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Journal of Osteology and Biomaterials The official journal of the BioCRA and SENAME Societies

BioCRA Biomaterial Clinical and histological Research Association President Giampiero Massei Deputy-president Alberto Rebaudi Scientific Director Paolo Trisi Secretary Teocrito Carlesi Editor in-chief Paolo Trisi, DDS PhD Scientfic director BioCRA, Pescara, Italy Associate Editors Gilberto Sammartino, MD DDS University of Naples Federico II, Naples, Italy Francesco Carinci, MD DMD University of Ferrara, Ferrara, Italy Assistant Editor Teocrito Carlesi, DDS Secretary BioCRA, Chieti, Italy Managing Editor Renato C. Barbacane, MD University G. d’Annunzio, Chieti, Italy

www.osteobiom.com

SENAME The South European, North African, Middle Eastern Implantology and Modern Dentistry Society President Gilberto Sammartino Deputy-president Ahmed M. Osman Scientific Director Paolo Trisi Secretary Faten Ben Amor

Editorial Board

Roberto Abundo, Turin, Italy Mario Aimetti, Turin, Italy Moshe Ayalon, Hadera, Israel Luigi Ambrosio, Naples, Italy Massimo Balsamo, Thiene, Italy Francesco Benazzo, Pavia, Italy Ermanno Bonucci, Roma, Italy Mauro Bovi, Rome, Italy Maria Luisa Brandi, Firenze, Italy Paul W. Brown, Pennsylvania, USA Ranieri Cancedda, Genova, Italy Saverio Capodiferro, Bari, Italy Sergio Caputi, Chieti, Italy Chih-Hwa Chen, Keelung, Taiwan Joseph Choukroun, Nice, France Gabriela Ciapetti, Bologna, Italy Giuseppe Corrente, Turin, Italy Massimo Del Fabbro, Milan, Italy Marco Esposito, Manchester, UK Antonello Falco, Pescara, Italy Gianfranco Favia, Bari, Italy Paolo Filipponi, Umbertide, Italy Pier Maria Fornasari, Bologna, Italy Bruno Frediani, Siena, Italy Sergio Gandolfo, Turin, Italy David Garber, Atlanta, USA Thomas V. Giordano, New York,USA Zhimon Jacobson, Boston, USA Jack T Krauser, Boca Raton, USA Richard J. Lazzara, West Palm Beach, USA Lorenzo Lo Muzio, Foggia, Italy Gastone Marotti, Modena, Italy Christian T. Makary, Beirut, Lebanon

Gideon Mann, Jerusalem, Israel Ivan Martin, Basel, Switzerland Milena Mastrogiacomo, Genoa, Italy Anthony McGrath, Santmore, UK Alvaro Ordonez, Coral Gables, USA Zeev Ormianer, Tel-Aviv, Israel Carla Palumbo, Modena, Italy Sandro Palla, Zurich, Switzerland Ady Palti, Kraichtal, Germany Michele Paolantonio, Chieti, Italy Giorgio Perfetti, Chieti, Italy Adriano Piattelli, Chieti, Italy Domenique P. Pioletti, Lausanne, Switzerland Paulo Rossetti, Saint Paul, Brasil Sergio Rosini, Pisa, Italy Ugo Ripamonti, Johannesburg, South Africa Henry Salama, Atlanta, USA Maurice Salama, Atlanta, USA Lucia Savarino, Bologna, Italy Arnaud Scherberich, Basel, Switzerland Nicola Marco Sforza, Bologna, Italy Christian FJ Stappert, New York, USA Marius Steigman, Neckargemünd, Germany Hiroshi Takayanagi, Tokyo, Japan Dennis Tarnow, San Francisco, USA Tiziano Testori, Milan, Italy Anna Teti, L’Aquila, Italy Oriana Trubiani, Chieti, Italy Alexander Veis, Thessaloniki, Greece Raffaele Volpi, Rome, Italy Giovanni Vozzi, Pisa, Italy Hom-Lay Wang, Michigan, USA Xuejun Wen, South Carolina, USA

Journal of Osteology and Biomaterials (ISSN: 2036-6795; On-line version ISSN 2036-6809) is the official journal of the Biomaterial Clinical and histological Research Association (BioCRA) and SENAME Societies. The Journal is published three times a year, one volume per year, by TRIDENT APS, Via Silvio Pellico 68, 65123 Pescara, Italy. Copyright ©2011 by TRIDENT APS. All rights reserved. No part of this journal may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information and retrieval system, without permission in writing from the publisher. The views expressed herein are those of the publisher or the Biomaterial Clinical and histological Research Association (BioCRA). Information included herein is not professional advice and is not intended to replace the judgment of a practitioner with respect to particular patients, procedures, or practices. To the extent permissible under applicable laws, the publisher and BioCRA disclaim responsibility for any injury and/ or damage to person or property as result of any actual or alleged libellous statements, infringement of intellectual property or other proprietary or privacy rights, or from the use or operation of any ideas, instructions, procedure, products, or methods contained in the material therein. The publisher assumes no responsibility for unsolicited manuscript.

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Instructions to Authors Review/editing of manuscripts. Manuscripts will be reviewed by the editorial chairman and will be subjected to blind review by the appropriate section editor and editorial board consultants with expertise in the field that the article encompasses. The publisher reserves the right to edit accepted manuscripts to fit the space available and to ensure conciseness, clarity, and stylistic consistency, subject to the author’s final approval. Adherence to guidelines. Manuscripts that are not prepared according to these guidelines will be returned to the author before review. MANUSCRIPT PREPARATION The journal will follow as much as possible the recommendations of the International Committee of Medical Journal Editors (Vancouver Group) in regard to preparation of manuscripts and authorship (Uniform requirements for manuscripts submitted to biomedical journals. Ann Intern Med 1997;126:36–47). See www.icmje.org. Manuscripts should be double-spaced with at least a one-inch margin all around. Number all pages. Do not include author names as headers or footers on each page. Title page. Page 1 should include the title of the article and the name, degrees, title, professional affiliation, and full address of all authors. Phone, fax, and e-mail address must also be provided for the corresponding author, who will be assumed to be the first-listed author unless otherwise noted. If the paper was presented before an organized group, the name of the organization, location, and date should be included. Abstract/key words. Page 2 of the manuscript should include the article title, a maximum of 300-word abstract, and a list of key words not to exceed 6. Abstracts for basic and clinical research articles must be structured with the following sections: (1) Aim, (2) Materials and Methods, (3) Results, and (4) Conclusions. Abstracts for all other types of articles (ie, literature reviews, clinical reports, technologies, and case reports) should not exceed 250 words and need not be structured. Introduction. Summarize the rationale and purpose of the study, giving only pertinent references. Clearly state the working hypothesis. Materials and Methods. Present materials and methods in sufficient detail to allow confirmation of the observations. Published methods should be referenced and discussed only briefly, unless modifications have been made. Indicate the statistical methods used, if applicable. Results. Present results in a logical sequence in the text, tables, and illustrations. Do not repeat in the text all the data in the tables or illustrations; emphasize only important observations. Discussion. Emphasize the new and important aspects of the study and the conclusions that follow from them. Do not repeat in detail data or other material given in the Introduction or Results section. Relate observations to other relevant studies and point out the implications of the findings and their limitations. Conclusions. Link the conclusions with the goals of the study but avoid unqualified statements and conclusions not adequately supported by the data. In particular, authors should avoid making statements on economic benefits and costs unless their manuscript includes the appropriate economic data and analyses. Acknowledgments. Acknowledge persons who have made substantive contributions to the study. Specify grant or other financial support, citing the name of the supporting organization and grant number. Abbreviations. The full term for which an abbreviation stands should precede its first use in the text unless it is a standard unit of measurement. Trade names. Generic terms are to be used whenever possible, but trade names and manufacturer name, city, state, and country should be included parenthetically at first mention. REFERENCES All references must be cited in the text, numbered in order of appearance. The reference list should appear at the end of the

Journal of Osteology and Biomaterials

article in numeric sequence. Do not include unpublished data or personal communications in the reference list. Cite such references parenthetically in the text and include a date. Avoid using abstracts as references. Provide complete information for each reference, including names of all authors (up to six). If the reference is part of a book, also include title of the chapter and names of the book’s editor(s). Journal reference style: Lazzara RJ, Testori T, Trisi P, Porter SS, Weinstein RL. A human histologic analysis of osseotite and machined surfaces using implants with 2 opposing surfaces. Int J Periodontics Restorative Dent 1999;19:117-29. Book reference style: Skalak R. Aspects of biomechanical considerations. In: Brånemark P-l, Zarb GA, Albrektsson T (eds). Tissue-Integrated Prostheses: Osseointegration in Clinical Dentistry. Chicago. Quintessence 1985:117-128. ILLUSTRATIONS AND TABLES - All illustrations must be numbered and cited in the text in order of appearance. - Illustrations and tables should be embedded in a PC Word document. JPEG files are highly recommended. For graphs and charts, do not use patterned fills. Solid tones or colors are recommended instead. - All illustrations and tables should be grouped at the end of the text. Radiographs–Submit the original radiograph as well as two sets of prints. Color–Color is used at the discretion of the publisher. No charge is made for such illustrations. Original slides (35-mm transparencies) must be submitted, plus two sets of prints made from them. Electronic Files–must contain all parts of the manuscript including figures and tables Resolution must be at least 600 dpi; files saved in jpeg format are preferred. Legends–Figure legends should be grouped on a separate sheet and typed double-spaced. UNITS OF MEASUREMENT Measurements of length, height, weight, and volume should be reported in metric units or their decimal multiples. Temperatures should be given in degrees Celsius and blood pressure in millimeters of mercury. All hematologic and clinical chemistry measurements should be reported in the metric system in terms of the International System of Units (SI). Description of teeth should use the American Dental Association (i.e., Universal/National) numbering system. COPYRIGHT All manuscripts accepted for publication become the property of TRIDENT APS. A copyright form must be signed by the authors, and returned to the Managing Editor. A file containing this form always accompanies the acceptance e-mail. Ethical Considerations in the Conduct and Reporting of Research: Protection of Human Subjects and Animals in Research When reporting experiments on human subjects, authors should indicate whether the procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008. If doubt exists whether the research was conducted in accordance with the Helsinki Declaration, the authors must explain the rationale for their approach and demonstrate that the institutional review body explicitly approved the doubtful aspects of the study. When reporting experiments on animals, authors should indicate whether the institutional and national guide for the care and use of laboratory animals was followed. It should be noted that certain research protocols may require human subject informed consent. It is the responsibility of the author to obtain this. Conflicts of Interest A conflict of interest and financial disclosure form must be submitted for each author. In the interest of transparency and to allow readers to form their own assessment of potential biases that may have influ-

enced the results of research studies, the Journal of Osteology and Biomaterials now requires that all authors declare potential competing interests relating to papers accepted for publication. Conflicts of interest are defined as those influences that may potentially undermine the objectivity or integrity of the research, or create a perceived conflict of interest. Authors are required to submit: 1) A statement in the manuscript, following Acknowledgments, that includes the source of any funding for the study, and defines the commercial relationships of each author. If an author has no commercial relationships to declare, a statement to that effect should be included. This statement should include financial relationships that may pose a conflict of interest or potential conflict of interest. These may include financial support for research (salaries, equipment, supplies, travel reimbursement); employment or anticipated employment by any organization that may gain or lose financially through publication of the paper; and personal financial interests such as shares in or ownership of companies affected by publication of the research, patents or patent applications whose value may be affected by this publication, and consulting fees or royalties from organizations which may profit or lose as a result of publication. An example is shown below. 2) A conflict of interest and financial disclosure form for each author. This form can be found on JOB website (http://www. osteobiom.com). The form should be completed by each author and provided to the corresponding author. The corresponding author is responsible for submitting these forms from each author when the manuscript is submitted. These forms should be sent to fax number +39 085 28427. These forms can also be uploaded in the cover letter area during the manuscript submission process. Conflict of interest information will not be used as a basis for suitability of the manuscript for publication. Example of conflict of interest statement: This study was supported by a grant from the Company____, City, State. Drs. ____, ____ and____ report no financial relationships related to any products involved in this study. Dr. ____ is on the scientific advisory board for ____ and gives lectures sponsored by the company. Dr. ____ is a consultant and shareholder of the “ private company____”, City, State. Dr. _____ is employed full-time as chief technical officer of the ____ Company. REPRINTS Corresponding authors may purchase reprints at the time pages are received for proofreading. Reprints can be purchased in 4-color or black and white. Submit manuscripts via JOB’s online submission service: www.osteobiom.com Manuscripts should be written in PC Word (doc) file format with tables preferably embedded at the end of the document. Original figures in pdf, tif or jpg. No paper version is required. Info: info@osteobiom.com

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Journal of Osteology and Biomaterials The official journal of the BioCRA and SENAME Societies

contents

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Review

Implants loading, delayed versus immediate loading protocols: a literature review. Dana Piek, Noga Harel, Shiri Livne, Zeev Ormianer

Original articles

of implant diameter on micromotion and insertion 13 Impact torque. An in vitro study. Paolo Trisi, Marco Berardini

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Processing, Characterization and Investigation of Suitability of Cowry Shells for Bone Graft Application. Oyatogun Grace Modupe, Esan Temitope Ayodeji, Oziegbe Elizabeth Obhioneh, Adebiyi Kehinde E, Togun Rachel Adetoro, Dare Enoch O, Adeoye Mosobalaje Oyebamiji

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Projecting cranial capacities using vertebral foramina circumferences.

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The morphometric measurements of humerus segments.

Elizabeth Celata

Kaur Jaswinder, Singh Zora

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Review

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Implants loading, delayed versus immediate loading protocols: a literature review. Dana Piek DMD, Noga Harel DMD, Shiri Livne DMD, Zeev Ormianer DMD*

Osseointegrated dental implants traditionally have been placed in accordance with 2-stage protocol. This method dictated that the implant should be submerged and left to heal for a period of 3 to 4 month in mandibles and 6 month in maxillae, according to Branemark’s protocol. Removable prosthesis in frequently used during implant healing period, though uncomfortable and requires maintenance and alterations. Both patient and dentist will benefit if healing period could be shortened without jeopardizing implant success rate. Branemark requirements for healing period was based on his trials with challenging patients, simultaneously involving poor bone quality and quantity with non optimized implant and prosthesis design. Gradually, clinicians considered to shorten healing period in more standard situations, mainly using methods that limit implant micromotion under the critical threshold of 150 and up. The protocols often mentioned are the immediate and early loading. These protocols exhibit survival rates similar to the conventional loading in the short term, but it seems that the difference might be revealed when a longer followup period will be available. Both protocols require careful patient selection aimed to achieve the best primary stability. The objective of this article is to review immediate and early loading definitions and protocols. (J Osteol Biomat 2012; 1:5-11)

Keywords: early loading, immediate loading, progressive loading, edentulous mandible, edentulous maxilla, dental implants, loading protocols, partial edentulism.

Lecturer, Dept. of Oral Rehabilitation, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel Correspondence to *Zeev Ormianer, DMD, Dept. of Oral Rehabilitation, School of Dental Medicine, Tel Aviv University, Ramat Aviv, Tel Aviv 69978 Israel email: ormianer@post.tau.ac.il Tel: +972-3-6124224 Fax: +972 (03)-6124226

INTRODUCTION Currently, treatment of edentulous patients using dental implants is a common practice. The ability to include dental implants in the treatment plan can facilitate dentists to overcome problems of missing teeth, extensive or localized, but it also compels them to deal with technical complexity of implant supported restorations. In addition, a treatment plan  that involves dental implants might take a additional time due to healing periods required for osseointegration. This process can be delayed further if bone augmentation and/or vertical or horizontal bone grafting is needed. On 1977 Branemark published his ten year follow up concerning dental implants, this article made a revolution regarding implant loading protocols4. Until then, it was common to load an implant immediately after implantation, assuming that stimulation of the bone will prevent the alveolar bone resorption. The fibrotic layer often seen between implant and bone was a desirable feature indicating a successful outcome, imitating the PDL. Branemark introduced his strict protocol to the dental world, this protocol included a list of demands, and the most important were: 1) use of a biocompatible material i.e. titanium; 2) use of a

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two stage procedure; 3) use of a stress free healing period of 3-6 months before loading; 4) use of an atraumatic surgery involving low speed drilling; 5) use a mucobuccal incision and avoid a crestal one; 6) use of sterile conditions as “in a fully equipped operatory”; 7) use of titanium ancillary; 8) avoid x-radiographsbefore the end of the healing period; 9) use of acrylic occlusal contact surfaces. Osseointegration was defined by Branemark as a direct structural and functional connection between ordered living bone and a surface of a load- carrying implant1. This correlation is formed by the reaction of bone to a implant titanium surface, leading to bone apposition without interposition of a fibrous scar tissue2. The most important factor for osseointegration is the initial stability achieved during the implantation. This Mechanical stability is dependent on implant design and bone quality in the osteotomy site. Initial stability is gradually replaced by secondary stability which is the result of maturation of the implant surrounding bone. The latter conversion is characterized by overactive osteoclasts, responding to the trauma created by the drilling process. Osteoclasts activity harms the initial stability and the secondary stability is not yet formed, thus this period is extremely sensitive to movements. This critical period lasts a month; two to six weeks after the implantation3. Branemark’s protocol was well documented in a study included 90 edentulous patients, mainly in the lower jaw6. This group was divided in half, 45 patients were rehabilitated by im-

Journal of Osteology and Biomaterials

plant overdenture and the rest was treated with implant fixed prostheses. This group of patients was kept under observation for 20 years, and the latest follow up was published on 2004, presenting excellent success rates of 93.09% for implant overdenture and 86.76% for implant fixed prostheses. Today, most patients demand rapid treatment because of the influence of the media for “teeth in a day”. These demands lead the dentist to lean towards shortened loading protocols, reducing the phase of edentoulism or interim prostheses. This review will examine the development of shortened loading protocols, comparing them to Branemark’s proven success. Three widespread loading protocols are commonly accepted literature8,9,10: Delayed occlusal loading – this is the conventional protocol introduced by Branemark. The protocol suggests a minimum period free of load, three months for mandible and six months for the maxilla. 1. Immediate occlusal loading – loading the implant up to 48 hours from the implantation. 2. Early occlusal loading - loading the implant from 48 hours to twelve weeks from the implantation. Another protocol is the progressive loading protocol, presented by Karl Misch11, describing in details the gradual phases of loading. This protocol is not considered abbreviated protocol that it requires four months without loading from the implantation until the beginning of the rehabilitation. The reason for a the intermediate protocols existing between conventional

to immediate loading is five years follow up data morebone loss compared with conventional loading. The purpose of early occlusal loading is to bridge the biological gap between destruction and formation of bone surrounding the implant, and offer high success rates, mainly regarding esthetic outcomes; bone loss followed by loss of soft tissue is an inconvenient complaint mostly in the anterior region8.


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Immediate loading protocols in the edentulous mandible The first region to be a candidate for immediate loading was the anterior mandible, known for its dense bone and lack of delicate anatomical structures. Between the two mental foramina bone volume is often kept, allowing the surgeon to insert standard implants with no preliminary procedure. One of the first articles12 presenting immediate implantation and immediate loading of screwed titanium plasma sprayed implants in the anterior mandible included 1793 implants on 484 patients, which were loaded with overdenture immediately or a few days after the implantation. Follow-up period lasted on average 32 months and the success rate was 87.96%.The implants were splinted to prevent micro-movements (over 150 microns) of the implants. Allowing the implants maintain adequate stability and thus to preserve success rates9. A recent review13, compared implant success rates of overdentures on two implants with early and dilates loading protocols. In was found that for short term follow up there was no effect of loading protocol on the implant’s success. Next site in terms of success rate is posterior mandible, i.e, distal to the mental foramen. In an article published in 199714 the authors resent a ten-year follow-up that included immediate loading, splinting teeth and implants and use of short implants. Ten consecutive patients who were about to lose their lower dentition (one of them already had a full mandibular denture received immediately and conventionally

loaded implants that were placed the same day. The immediate loaded implants were used to support the interim rehabilitation (along with remaining teeth). Success rates for these implants were lower (84.7%) comparing the conventionally loaded (93.4%), but most of the implants that failed out of the former group were 7 mm short. It cannot be exclude that splinting teeth and implants contributed to lower success rates, mainly because most teeth were mobile and did not maintain implant stability. Interestingly, implants that were immediately loaded and survived didn’t show a difference in bone resorption comparing conventional loading14.

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Immediate loading protocols in the Maxilla The upper jaw is a challenging site for immediate implant placement, both in terms of bone quality and of anatomical structures that make it difficult without using pre-prosthetic surgical procedures i.e. the maxillary sinuses and nasal cavity. In case report published199515 the authors demonstrated immediate loading in both upper and lower jaws of two complex patients. In both cases success rate was 100%. It was only two years later when more extensive article was published, including placing 107 implants in ten patients. in both jaws showing high success rate. Only three implants failed and all of them were placed in the mandible. In the conclusions, the aothors indicated that while implants can be placed into immediate function, a delayed loading protocol still remains the treatment of choice. Based on the high success rate, guidelines for immediate loading were obtainable16: 3. Immediate loading should be attempted in edentulous arches only, to create cross arch stability. 4. Implants should be at least 10 mm long. 5. A diagnostic wax up should be used for template and provisional restoration fabrication. 6. A rigid metal casting should be used on the lingual aspect of the provisional restoration. 7. A screw retained provisional restoration should be used where possible. 8. If cemented, the provisional restoration should not be removed dur-

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ing the 4-6 month healing period. 9. All implants should be evaluated with Periotest at stage 1, and the implants that show the least mobility should be selected for immediate loading. 10. The widest possible anterior-posterior distribution of implants should be utilized to provide resistance to rotational forces. 11. Cantilevers should be avoided in the provisional restoration. In an article presenting implants in the upper jaw, included 302 implants immediately loaded in the maxilla, 98% survival rate was reported. Although the focus of this research was the differences between immediate implantation and healed sites, there is relevant data regarding immediate loading. After 3-years of follow up only six implants failed to integrate. The authors attributed the failure to shorter length and narrow diameter of the implant, and concluded that immediate loading of implants splinted by cross arch rehabilitation might be as predictable as Branemark’s two stage protocol17.

Journal of Osteology and Biomaterials

Immediate loading protocols for partially edentulous jaw. The main advantage of using implants in a partially edentulous patient is the ability to avoid interim removable prosthetic during healing phase. The acrylic provisional crown supports the gingival tissue from the day of implantation. It allows the clinician to design the appropriate gingival contour, which would benefit the final prosthetic outcome. There is not sufficient data regarding success rate of single or a limited number of missing teeth restored by implants. It is important to note that the adjacent remaining teeth allow the clinicians to under occlude the interim restoration, what is defined in the literature as nonfunctional early restoration or immediate restoration9. This immediate restoration is not fully loaded and considered as an aesthetic restoration only. Food bolus and masticatory muscles also apply some force on the restoration, but it is not as powerful as close contact with the opposite dentition. The current published data often does not differentiate between immediate loading and immediate restoration and it is difficult to draw any conclusions regarding the precise success rate of immediate loading in the partially edentulous patient10. One of the articales that compared both cases showed no difference regarding survival rates, bone loss or soft tissue behavior. At a 3-year follow-up, success rates were 96%18. Other article from 2003 compared immediate loading with full occlusal contacts versus conventional loading. In this article, success rates after 42 months of follow up were 98.9%, implants that failed

were from the conventional loading control group. The authors classified the implants according to bone loss. 95.7% of the immediately loaded group lost 0-1mm bone in 2 years, compared to 93.3% in the control group19.


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Early loading protocols for the edentulous jaw. As previously mentioned, early loading is defined as restoration of implants 48 hours to 12 weeks from implantation. This period of time consists also the stage that the implants should not be subjected to micro-movement. Bone biology shows that 2 to 6 weeks after implant placement, the bone is less stable due to remodeling process that temporarily harm the primary stability3. A study of 37 edentulous patients who received fixed prosthesis two weeks from implant placement showed 84.9% success rate after 4.5 years of follow up; five implants were placed between the mental foramina and the patient was given fixed prosthesis with distal cantilever. This research included total of 185 implants and showed lower success rates compared with reported higher success rates for the front area of ​​the mandible. The authors did not recommend this kind of therapy because of high complication rate20. In a review from 2005 no differentiation between early and immediate loading in the anterior region of the mandible was done. In both cases success rates exceed 90% in short to medium terms, with no statistical significance to the type of rehabilitation, fixed prostheses or overdenture21. The same authors reported 93.09% and 86.76% success rates for overdenture and fixed prostheses, respectively – after 20 years of follow up of patients treated according to Branemark’s protocol6,7. Another interesting detail appears from this article is that a minimum of 4 implants required for a successful fixed prostheses in the edentulous mandible21.

Another article describes the restoration of the edentulous maxilla with early loading protocol. In the article22, rehabilitation procedures started 3 weeks from implant placement and the final prosthesis was delivered after another 3 weeks. 12 patients received 6-8 implants in the maxilla. The metal frame was divided to 2-4 segments, depending on the number of implants. Despite of the extensive prosthetic procedure even during the delicate stage of bone remodeling and no cross-arch stabilization, success rates after a year of follow up was high as 98.9%. Follow-up period of one year is too short to derive conclusions, especially in terms of loading and scheduling of rehabilitation procedures.

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Early loading protocol for partially edentulous jaw. Few articles deal with early loading in the partially edentulous jaw. In one study, 104 implants were placed in 51 partially edentulous patients. Most of the implants were placed in the posterior mandible (85%), all implants were loaded with provisional restoration six weeks after implant placement. The emphasis of the study was crestal bone changes during 3 years of follow up. 40% of the implants showed elevated bone measurements after 3 years. Implant survival was 99.03% for the same time period23. As mentioned earlier, the purpose of early loading as opposed to immediate loading is to preserve bone and soft tissue. Two papers recently publish by an Italian group, compared immediate loading (with no occlusal contacts for the first two months) and early loading two months from implant placement. It is unclear if there is a real difference between both groups because the both were fully loaded two months after implant placement24,25. The first article24 followed 52 patients for 14 months. After this time period there was no difference between the two groups regarding bone levels and soft tissue. Five years from implant placement there was another data collection for the same group of patients. the results were different even though bone levels were not statistically different (1.2 on average for 5 years in both groups), soft tissue recession of 0.2mm was observed for the immediately loaded group. Early loaded group did not show any soft tissue recession25. It should be noted that

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although there was no statistical difference between groups regarding soft tissue after 14 months of follow up, clinicians seemed to notice a slight difference in crown length: loss of 0.01mm and 0.13mm for the early and immediately loaded groups respectively24. In summary, both patients and dentists are benefits from immediate loading procedures, but the concern of failure is still evident. As seen, it is possible to achieve high success rates in cases of immediate loading implants, but it requires the restorative dentist to follow specific criteria such as primary stability, measured by high insertion torque26. There is still no uniformity in loading timing and specific criteria for loading protocols; it is for the dentist to be updated in recent literature and to adapt the changing protocols to his patients.

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Ormanier Z. et al.

REFERENCES 1. Branemark P-I, Zarb GA, Albrektsson T. Tissue-integrated prostheses: osseointegration in clinical dentistry. Chicago:quintessence, 1985:11. 2. Albrektsson T, Johansson C. Osteoinduction, osteoconduction and osseointegration. Eur Spine J. 2001;10 Suppl 2:S96-101. 3. Raghavendra S, Wood MC, Taylor TD. Early wound healing around endosseous implants: a review of the literature. Int J Oral Maxillofac Implants 2005;20(3):425-31. 4. Brånemark PI, Hansson BO, Adell R et al. Osseointegrated implants in the treatment of the edentulous jaw. Experience from a 10-year period. Scand J Plast Reconstr Surg Suppl. 1977;16:1-132. 5. Szmukler-Moncler S, Piattelli A, Favero GA, Dubruille JH. Considerations preliminary to the application of early and immediate loading protocols in dental implantology. Clin Oral Implants Res 2000;11(1):12-25. 6. Attard NJ, Zarb GA. Long-term treatment outcomes in edentulous patients with implant overdentures: the Toronto study. Int J Prosthodont 2004;17(4):425-33. 7. Attard NJ, Zarb GA. Long-term treatment outcomes in edentulous patients with implant-fixed prostheses: the Toronto study. Int J Prosthodont 2004;17(4):417-24. 8. Grütter L, Belser UC. Implant loading protocols for the partially edentulous esthetic zone. Int J Oral Maxillofac Implants. 2009;24 Suppl:169-79. 9. Misch CE, Wang HL, Misch CM, Sharawy M et al. Rationale for the application of immediate load in implant dentistry: Part I. Implant Dent 2004;13(3):207-17. 10. Cochran DL, Morton D, Weber HP.Consensus statements and recommended clinical procedures regarding loading protocols for endosseous dental implants. Int J Oral Maxillofac Implants 2004;19 Suppl:109-13. 11. Misch C. Progressive bone loading. Dent Today 1995;14(1):80-3. 12. Babbush CA, Kent JN, Misiek DJ. Titanium plasma-sprayed (TPS) screw implants for the reconstruction of the edentulous mandible. J Oral Maxillofac Surg 1986;44(4):274-82.

13. Ma S, Payne AG. Marginal bone loss with mandibular two-implant overdentures using different loading protocols: a systematic literature review. Int J Prosthodont 2010;23(2):117-26. 14. Schnitman PA, Wöhrle PS, Rubenstein JE et al. Ten-year results for Brånemark implants immediately loaded with fixed prostheses at implant placement. Int J Oral Maxillofac Implants 1997;12(4):495-503. 15. Salama H, Rose LF, Salama M et al. Immediate loading of bilaterally splinted titanium root-form implants in fixed prosthodontics--a technique reexamined: two case reports. Int J Periodontics Restorative Dent 1995;15(4):344-61. 16. Tarnow DP, Emtiaz S, Classi A. Immediate loading of threaded implants at stage 1 surgery in edentulous arches: ten consecutive case reports with 1- to 5-year data.Int J Oral Maxillofac Implants 1997;12(3):31924. 17. Artzi Z, Kohen J, Carmeli G et al. The efficacy of full-arch immediately restored implant-supported reconstructions in extraction and healed sites: a 36-month retrospective evaluation. Int J Oral Maxillofac Implants 2010;25(2):329-35.

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lary fixed full-arch prostheses. Clin Oral Implants Res 2008;19(11):1129-34. 23. Bornstein MM, Lussi A, Schmid B et al. Early  loading  of nonsubmerged titanium implants with a sandblasted and acid-etched (SLA) surface: 3-year results of a prospective study inpartially  edentulous patients. Int J Oral Maxillofac Implants 2003;18(5):659-66. 24. Galli F, Capelli M, Zuffetti F et al. Immediate non-occlusal vs.  early  loading  of dental implants in partially edentulous patients: a multicentre randomized clinical trial. Peri-implant bone and soft-tissue levels. Clin Oral Implants Res 2008;19(6):546-52. 25. Capelli M, Esposito M, Zuffetti F et al. A 5-year report from a multicentre randomised clinical trial: immediate nonocclusal versus  early  loading  of dental implants in partially edentulouspatients. Eur J Oral Implantol 2010;3(3):209-19. 26. Esposito  M,  Grusovin  MG, Willings M et al. The effectiveness of immediate, early, and conventional loading of dental implants: a Cochrane systematic review of randomized controlled clinical trials. Int J Oral Maxillofac Implants  2007;22(6):893904.

18. Degidi M, Nardi D, Piattelli A. A comparison between immediate loading and immediate restoration in cases of partial posterior mandibular edentulism: a 3-year randomized clinical trial. Clin Oral Implants Res 2010;21(7):682-7. 19. Cannizzaro G, Leone M. Restoration of partially edentulous patients using dental implants with a microtextured surface: a prospective comparison of delayed and immediate full occlusal loading. Int J Oral Maxillofac Implants 2003;18(4):512-22. 20. Schwarz S, Gabbert O, Hassel AJ et al. Early loading of implants with fixed dental prostheses in edentulous mandibles: 4.5-year clinical results from a prospective study. Clin Oral Implants Res 2010;21(3):284-9. 21. Attard  NJ,  Zarb  GA. Immediate and early implant loading protocols: a literature review of clinical studies. J Prosthet Dent 2005;94(3):242-58. 22. Lai HC, Zhang ZY, Zhuang LF et al. Early loading of ITI implants supporting maxil-

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Original Article

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Impact of implant diameter on micromotion and insertion torque. An in vitro study Paolo Trisi1*, Marco Berardini2

Aim: Measuring impact of implant diameters on primary stability in relation to three different bone densities in vitro (Soft, Medium, Hard); the present study seeks to determine whether micromotion at the bone implant interface is related to implant diameters. Materials and methods: A total of 64 TRI® dental implants (TRI Dental Implants Int. AG Lindenstrasse 14, Baar, Svizzera) were used. 33 implants had a diameter of 4,1 mm and 31 implants had a diameter of 4,7 mm. The length of all implants was 10 mm. Implants were placed in fresh bovine bone samples representing three categories of density: hard, medium and soft (H, M, S). Customized electronic equipment connected to a PC was used to register the peak and insertion torque (IT) data. A loading device, consisting of a digital force gauge and a digital micrometer was used to measure the micromovements of the implant during the application of 25 N lateral forces. The data were analyzed for statistical significance by unpaired t-test and Pearson coefficient of correlation using a statistical software. Results: Data showed no statistically significant differences in micromotion between 4,1 diameter implants and 4,7 diameter implants in different bone densities. Both 4,1 and 4,7 implants, when inserted in the H bone, showed micromotion values statistically lower (P<0,0001) than when the same implants were placed in the S bone. The micromotion for 4,1 diameter implants changed significantly depending on the type of bone in which they are inserted. No statistically differences were found between 4,7 mm diameter implants inserted in M vs H bone while in S bone vs M bone were significant different. Implants with large diameter (4,7 mm) demonstrated higher mean values of IT than implants with smaller diameter (4,1 mm) but these differences were statistically significant only when implants were inserted in S bone. The statistical analysis, using Pearson coefficient of correlation, showed that by increasing IT the primary stability (P<0,0001) in both implant diameters increases significantly. Conclusions: Results show that increasing the implant diameter from 4,1 mm to 4,7 mm do not significantly reduce the level of micromotion. Bone densities influenced significantly the primary stability of implants regardless of implant diameter. The peak of insertion torque, which has a close relationship with primary implant stability, has a significant correlation with bone density but it does increase significantly with the widening of implant diameter only in the S bone type. In the soft bone the primary stability is not very high and so protocols of immediate loading in this type of bone are to be considered with caution. (J Osteol Biomat 2012; 1:13-19)

Key words: implant primary stability, implant diameter, bone density, insertion torque, micromotion, immediate loading, implant geometry. 1 Scientific Director, Biomaterial Clinical Research Association Private Practice, Pescara, Italy 2 Private Practice, Pescara, Italy

Corresponding author: *Dr. Paolo Trisi Biomaterials Clinical Research Association Via San Silvestro 163/3 65132 Pescara - Italy Fax: +39-85-28427 e-mail: paulbioc@tin.it

INTRODUCTION To improve patient comfort, deviations from the very successful standard of osseointegration protocols are being developed and protocols of immediate loading have been reported in several studies1. The possibility of immediate functional loading of implants has been explored with particular success for the anterior mandible and with lesser success for the upper jaw and posterior mandible2. Implant stability depends on the direct mechanical connection between its surface and the surrounding bone and can be divided into primary and secondary stability. There is sufficient evidence to suggest that the degree of achieved primary stability  during immediate loading protocols is dependent on several factors including bone density, implant shape, design and surface characteristics and surgical technique3. It has also been demonstrated that the cause of failure of immediate loaded  implants is due to the  micromotion  on the bone-implant  interface induced by immediate loading4. Micromovements of implants are responsible of the failures of bone healing after fracture5. Nowadays there are no instruments which can directly measure the amount of micromotions in the mouth of the patient. The Periotest (PTV) measures temporal contact

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Trisi P. and Bernardini M.

of the tip of the instruments during repetitive percussions on the implants. Resonance frequency analysis (RFA) developed by Meredith et al6 uses specified resonance characteristics of acoustically excited implants and utilizes a small L-shaped transducer which is screwed onto an implant fixture abutment. A previous study of Trisi et al7 demonstrated that the ISQ value is related to the amount of implant micromotion with a statistically significant correlation. Moreover, a high peak of insertion torque is considered advantageous in improving primary stability8. The host bone density can deeply influence the values of insertion torque and recent studies of review of literature showed that there is a positive association between implant primary stability and bone mineral density of the receptor site9. Since the implant geometry is considered a key factor, in order to achieve the primary stability10, we performed a literature search on the impact of implant diameter on micromotion immediately after placement and we found no study on this topic. Therefore, the aim of the present study was to conduct an experimental in vitro test of the micromotion of implants of two different diameters after placement into fresh bovine bone of different densities (Soft, Medium, Hard) in order to assess the differences of primary stability of different diameters. MATERIALS AND METHODS A total of 64 TRI® dental implants (TRI Dental Implants Int. AG Lindenstrasse 14, Baar, Switzerland) were tested: 33 implants were 4,1x10 mm and 31 were 4,7x10 mm. Implants

Journal of Osteology and Biomaterials

were inserted in the three different bone qualities, including hard (H), medium (M) and soft (S), as defined above. In the group of 4,1 mm in diameter 9 implants were inserted in S bone, 12 implants in M bone and 12 implant in the H type. In the group of 4,7 mm in diameter 9 implants were inserted in S bone, 12 implants in M Bone and 10 implants in the H type. The test was performed on 2cmx2cm samples of fresh humid bovine bone representative of the following quality categories: hard, medium and soft (H-M-S). The bone qualities were selected according to drilling resistance11 and a preliminary histologic analysis of the bone structure. Hard bone is dense with a completely compact structure. Medium bone is average hard bone with a 2–3mm cortical layer and a normal cancellous structure inside. Soft bone has low drilling resistance and no cortical layer with a low-density cancellous structure. 4,1mm and 4,7mm diameter TRI®-implants and 10mm in length were used for this study. Each implant was fitted with a one-piece fixed straight abutment 11mm in length to allow for the application of the lateral load. The implants were placed according to the manufacturer’s instructions using the appropriate burs. In the S bone implants were placed using only the 2mm pilot drill. In the H bone 4,1-diameter implants were placed after using the appropriate 4,1 mm tapper while 4,7-diameter implants were placed without using a tapper because we did not have it. For this reason 4,7 diameter implants inserted in H bone remained about 1,5-2 mm above the bone ridge. A customized digitally controlled hand wrench was used to measure the peak

insertion torque. In addition, electronic equipment consisting of a digital handoperated torque wrench, equipped with a calibrated strain gauge and connected to a PC reading the peak insertion torque value every 0.5 ms, was customized for this study. To obtain the peak insertion torque, the signal was subsequently evaluated by the MECODAREC software (ATech s.r.l., Bergamo, Italy). After implant placement, the bone blocks were fixed on a customized loading device for evaluation of micromovement. This device consisted of a digital force gauge [Akku Force Cadet (range of 0–90N and accuracy of 0.5%), Ametek, Largo, FL, USA] and, on the opposite side, a digital micrometer (Mitutoyo Digimatic Micrometer, Kawasaki, Japan) that measured the micromovements of the abutment during the lateral load application. Horizontal forces of 25 N/mm were tested on each implant, and the lateral movement of the abutment was measured by the digital micrometer at 10mm above the crest. On each implant, the load application was repeated two times for 2 s, simulating the occlusal load in a patient’s mouth. The values of these two measurements was calculated for each implant. We also compared statistically the correlation between torque-in values and micromotion in both implant groups regardless of the type of bone in which they were inserted. The data were analyzed for statistical significance by unpaired T-test and Pearson coefficient of correlation using the statistical software Graphpad Prism 5 (www.graphpad.com).


Trisi P. and Bernardini M.

RESULTS The average micromotion of the implants during the lateral load application are shown in the graphs (Fig.1, Fig. 2, Fig. 3). 4,1-diameter implants showed an average value of 215,2 ±75 S.D. µm of lateral micromovements when inserted in S bone (Fig.1), 29,83±17 S.D. µm when inserted in M bone (Fig.2) and 21,17±12 S.D. µm when inserted in H Bone. 4,7-diameter implants showed an average value of 193,7±82 S.D. µm when inserted in S bone, 26,63±9 S.D. microns when inserted in M bone and 27,4±11 S.D. µm when inserted in H Bone (Fig.3). The statistical analysis with unpaired t-test showed no statistical differences between the average values of micromovements between different implants diameter in the same bone density. Data are shown in the table 1. We also compared the micromotion value of implants in relation to the type of bone in which implants were inserted. Both 4,1 and 4,7 implants, when inserted in the H bone type, showed micromotion values statistically lower

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Figure 1. Diameter vs Micromotion in soft bone (S)

Figure 2. Diameter vs Micromotion in medium bone (M)

Table 1. Comparison of micromotion between 4,1 diameter implants and 4,7 diameter implants in different bone densities (S, M, H) Ø 4,1 mm

Ø 4,7 mm Mean ± S.D. µm

Mean ± S.D. µm

P value

SOFT BONE

215,2 ± 75

N=18

193,7 ± 82 N=18

0,4174*

MEDIUM BONE

29,83 ± 17

N=24

26,63 ± 9

N=24

0,3885*

21,17 ± 12

N=24

27,4 ± 11

N=20

0,1109*

HARD BONE * Non significant **Significant

Table 2. Comparison of micromotion between implants of the same diameter inserted in S bone vs H bone SOFT BONE

MEDIUM BONE Mean ± S.D. µm

Mean ± S.D. µm

P value

4,1 diameter implants

215,2 ± 75

N=18

29,83 ± 17

N=24

< 0,0001**

4,7 diameter implants

193,7 ± 82

N=18

26,63 ± 9

N=24

<0,0001**

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Table 3. Comparison of micromotion between implants of the same diameter inserted in M bone vs H bone MEDIUM BONE

HARD BONE Mean ± S.D. µm

4,1 diameter implants 4,7 diameter implants * Non significant **Significant

Mean ± S.D. µm

P value

29,83 ± 17

N=24

21,17 ± 12

N=24

0,0465**

26,63 ± 9

N=24

27,4 ± 11

N=20

0,8016*

Table 4. Comparison of micromotion between implants of the same diameter inserted in S bone vs M bone SOFT BONE 4,1 diameter implants 4,7 diameter implants * Non significant **Significant

HARD BONE Mean ± S.D. µm

Mean ± S.D. µm

215,2 ± 75

N=18

21,17 ± 12

N=24

< 0,0001**

193,7 ± 82

N=18

27,4 ± 11

N=20

< 0,0001**

(P<0,0001) than the same implants placed in the S bone. The comparison of data is shown in the table 2. The statistical analysis showed that micromotion for 4,1 diameter implants changes significantly depending on the type of bone in which they are inserted. No statistically differences were found between 4,7 diameter implants inserted in M vs H bone while in S bone vs M bone were significant different (Tables 3-4). In the S bone, with no cortical layer, it was possible to reach an average of 50

Figure 4. Diameter vs Torque-in in soft bone (S)

Journal of Osteology and Biomaterials

±6,61 S.D. N/cm of IT for 4,7-diameter implants and 40,56±4,64 S.D. N/cm for 4,1-diameter implants. The bone started to be damaged beyond 50 N/ cm, and the implants started spinning (Fig.4). The average of insertion torque of 4,7 diameter implants, when they were inserted in S bone, was significantly higher (P=0,0029) than the IT of the group of 4,1 diameter implants. In the M bone the average of peak insertion torque value was 80±21,98 S.D. N/cm for 4,1-diameter implants and

P value

87,50±10,34 S.D. N/cm for 4,7-diameter implants (Fig.5). The statistical analysis showed no significant differences (P=0,9065) of insertion torque between the two groups of implants when inserted in M bone. In the H bone type the average of insertion torque was 86,88±9,64 S.D. N/ cm using 4,1-diameter implants and 96±8,43 S.D. N/cm using 4,7-diameter implants. (Fig.6). In H bone, torque-in values are not statistically different (P=0,0516) between 4,1 diameter implants e 4,7 diameter implants. The statistical analysis showed that increasing torque insertion values increases significantly the primary stability (P<0,0001) in both groups (Pearson r: Ø 4,1= -0,7734; Ø 4,7=-0,7982). DISCUSSION Primary stability is nothing more than the absence of micromotion immediately after implant placement and it is achieved when the implant is positioned into the host bone site that it is well seated; it has been defined as “a sufficiently strong initial bone-implant


Trisi P. and Bernardini M.

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Table 5. Mean values of IT between the two different implant diameters in S bone type Mean value of IT in S bone N/cm

Standard Deviation

4,1 implant diameter

40,56

±4,64

4,7 implant diameter

50

±6,61

Table 6. Mean values of IT between the two different implant diameters in M bone type Mean value of IT in M bone N/cm

Standard Deviation

4,1 implant diameter

80

±21,98

4,7 implant diameter

87,50

±10,34

Table 7. Mean values of IT between the two different implant diameters in H bone type Mean value of IT in H bone N/cm

Standard Deviation

4,1 implant diameter

86,88

±9,64

4,7 implant diameter

96

±8,43

fixation”12. The peak insertion torque measures the maximum torque of insertion which is obtained during implant placement until it is totally lodged in its site. This procedure could be influenced by the preparation of host bone sites, the bone density and the type of implant. A recent study13 has demonstrated that high insertion torque values are related to a high degree of primary stability of

an implant and that, by increasing the peak insertion torque, the level of implant micromotion is reduced. The results of the present study show that by increasing the implant diameter from 4,1 mm to 4,7 mm, the peak of insertion torque increases significantly only in soft bone. Bilhan et al14 in a previus “in vitro study” inserted implants in cancellous bone and they stated that, in this type of bone appear to be

Figure 5. Diameter vs Torque-In in medium bone (M)

useful, in order to enhance the primary stability, to place implants with a wider diameter. Our statistical analysis also showed that, the peak of insertion torque had a significant correlation with primary stability: by increasing the IT (regardless of the diameter) micromotion decreases under lateral loads. Therefore, the peak of insertion torque has a close relationship with primary implant stability. The peak insertion torque is also correlated to the host bone densities and we registered the highest values of torque-in when implants were inserted in cortical bone (H). Rebaudi et al15 evaluated in vivo the correlation between implants insertion torque and bone density. Statistically, significant correlation was found between bone volume and IT values (r = +0.771, P < 0.0001). They did not find any statistically significant correlation between  implant  length and/or  diameter  and insertion torque in all bone densities. The data of this study show that pri-

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Trisi P. and Bernardini M.

mary stability, measured with our “in vitro” model, is not significantly influenced by implants diameter; the increase in diameter from 4,1 mm to 4,7 mm do not show statistically higher levels of primary stability. Implants that were inserted in H bone showed the lowest mean micromovements values and the highest values of insertion torque. Statistically significant differences in micromotion under lateral forces were found between implants inserted in cortical dense bone (H) and implants inserted in soft bone (S) regardless of the diameter. Many studies12,16 demonstrated that the presence of a cortical bone increases the primary stability. Hsu JT17 et al investigated the effect of the cortical thickness and the trabecular strengths on the primary stability of implants; they used synthetic bone models and they concluded that the initial stability, at the time of implant placement, is influenced by both the cortical bone thickness and the strength of trabecular bone. Therefore, the quality of the host bone is a key factor in order to achieve good primary stability. Results of recent studies show that high implant insertion torque in dense cortical bone does not induce bone necrosis or implant failure18, but it does increase the primary stability of implants19, which is extremely important in immediate loading protocols. There are, in addition, no significant differences between different diameters on the values of micromovements under lateral forces on implants inserted in medium bone or in hard bone. Probably, it is due to the fact that, only the first millimeters of cortical bone are im-

Journal of Osteology and Biomaterials

portant for implant stability. Marquezam et al20, in an in vitro study, evaluated the primary stability of miniscrews inserted in two different bone densities and they found no differences when cortical bone was around 1 mm thick. The results of the present study show that, by increasing the implant diameter from 4,1 mm to 4,7 mm the level of micromotion is not significally reduced in all bone densities. In H bone, despite the large diameter implants (4,7 mm) reached an average IT values higher (no significant differences) than 4,1 mm diameter implants, micromotion was higher in the 4,7 mm group of implants (no significant differences). Probably this difference is due to the fact that we did not have the tapper 4,7 in diameter and 4,7 implants in this type of bone (H) remained 1,5-2 mm above the bone ridge. In S bone the average of micromotions exceed the critical level of 100-150 microns in both the implants diameter and this figure suggests caution when a protocol of immediate loading in this type of host bone is scheduled. In fact, previous animal studies21 reported that a micromotion above the value of 100 micrometers could induce bone resorption at the interface and these micromovements are able to produce fibrosis around implants. CONCLUSION Increasing implant diameter from 4,1 mm to 4,7 mm does not significantly influence the primary stability in any type of bone density. Protocols of immediate loading in soft bone should be considered with caution and the increase of diameter from 4,1 mm to

4,7 mm seems, from our data, not to be able to increase significantly the primary stability. The density of host bone is a key parameter in order to obtain high values of primary stability after the implant insertion and the peak of insertion torque has a significant correlation with primary stability. Aknowledgments The authors wish to thank the company TRI® Dental Implants. The authors declare that they have no financial relationship or interest that may pose a conflict of interest between them and TRI® Dental Implants.


Trisi P. and Bernardini M.

REFERENCES 1. Attard NJ, Zarb GA. Immediate and early  implant  loading  protocols: a literature review of clinical studies. J Prosthet Dent. 2005;94(3):242-58. 2. Del Fabbro, M., Testori, T., Francetti, L., Taschieri, S. & Weinstein, R. Systematic review of survival rates for immediately loaded dental implants. Int J Periodontics Restorative Dent 2006;26: 249-263 3. Javed F, Romanos GE. The role of primary  stability  for successful immediate loading of dental implants. A literature review. J Dent. 2010;38(8):612-20 4. Szmukler-Moncler, S. Salama, H, Reingewirtz, & Dubruille, J.H. Timing of loading and effect of micromotion on bone-dental implant interface: a review of experimental literature. J Biomed Mater Res 1998;43: 192–203. 5. Perren, S.M. Evolution of the internal fixation of long bone fractures. The scientific basis of biological internal fixation: choosing a new balance between stability and biology. J Bone Joint Surg 2002;84: 10931110. 6. Meredith N, Alleyne D, Cawley P Quantitative determination of the stability of implant-tissue interface using resonance frequency analysis. Clin Oral Implants Res 1996;7:261-267. 7. Trisi, Carlesi, Colagiovanni, Perfetti Implant Stability Quotient (ISQ) vs direct in vitro measurement of primary stability (micromotion): effect of bone density and insertion torque J Osteol Biomat 2010;1:141-151. 8. O’Sullivan D, Sennerby L, and Meredith N Measurements comparing the initial stability of five designs of dental implants: a human cadaver study. Clinical Implant Dentistry & Related Research 2000;2: 85-92. 9. Marquezan M, Osório A, Sant’Anna E, Souza MM, Maia L. Does bone mineraldensity  influence the primary stability of dental implants? A systematic review. Clin. Oral Impl. Res. 2011. 10. Lachmann S, Laval JY, Axmann D, Weber H, Influence of  implant  geometry  on  primary insertion stability and simulated peri-

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implant  bone loss: an in vitro study using resonance frequency analysis and damping capacity assessment. Int J Oral Maxillofac Implants 2011;26(2):347-55.

20. Marquezan M, Souza M, Araùjo MT, Nojima LI, Nojima Mda C. Is miniscrew primary stability influenced by bone density? Braz Oral Res 2011;25(5):427-32.

11. Trisi P, and Rao W. Bone classification: clinical-histomorphometric comparison. Clin Oral Implants Res 1999;10: 1-7.

21. Overgaard S, Lind M, Glerup H, Bünger C, Søballe K, Porous-coated versus grit-blasted surface texture of hydroxyapatite-coated implants during controlled micromotion: mechanical and histomorphometric results. J Arthroplasty 1998 ;13(4):449-58.

12. Roberts W E. Bone dynamics of osseointegration, ankylosis, and tooth movement. J Indiana Dent Ass 1999;78: 24-32. 13. Trisi P, De Benedittis S, Perfetti G, Berardi D. Primary stability, insertion torque and bone density of cylindric implant ad modum Branemark: is there a relationship? An in vitro study. Clin Oral Implants Res. 2011;22(5):567-70. 14. Bilhan H, Geckili O, Mumcu E, Bozdag E, Sünbüloğlu E, Kutay O. Influence of surgical technique, implant shape and diameter on the  primary  stability  in cancellous bone. J Oral Rehabil 2010;37(12):900-7 15. Makary C, Rebaudi A. Mokbel N, Naaman N, Peak insertion torque correlated to histologically and clinically evaluated bone density. Implant Dent 2011; 20(3):182-91. 16. Andrés-Garcìa R, Vives NG, Climent FH, Palacìn AF, Santos VR, Climent MH, Bullòn P, In vitro evaluation of the influence of the cortical bone on the  primary  stability  of two  implant systems. Med Oral Patol Oral Cir Bucal 2009;14(2):E93-7. 17. Hsu JT, Fuh LJ, Tu MG, Li YF, Chen KT. GUang HL. The Effects of Cortical Bone Thickness and Trabecular Bone Strength on Noninvasive Measures of the Implant  Primary Stability Using Synthetic Bone Models. Clin Implant Dent Relat Res 2011;20. 18. Trisi P, Todisco M, Consolo U, Travaglini D. High versus low implant insertion torque: a histologic, histomorphometric, and biomechanical study in the sheep mandible. Int J Oral Maxillofac Implants 2011;26(4): 837-49. 19. Trisi P, Perfetti G, Baldoni E, Berardi D, Colagiovanni M, Scogna G. Implant micromotion is related to peak insertion torqu and bone density. Clin Oral Impl Res 2009;20:467-471.

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Original article

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Processing, Characterization and Investigation of Suitability of Cowry Shells for Bone Graft Application Oyatogun Grace Modupe,1* Esan Temitope Ayodeji,2 Oziegbe Elizabeth Obhioneh,3 Adebiyi Kehinde E,4 Togun Rachel Adetoro,5 Dare Enoch O,6 Adeoye Mosobalaje Oyebamiji1 Aim: This work attempted to process and investigates the suitability of cowry shell as a bone graft substitute material. Materials and Methods: The cowry shell was washed with distilled water to remove foreign bodies such as dust, dirt, and insect larva which might have entered it from the sea. They were crushed and dried in the oven at 80Ë&#x161;C for about 20 minutes. The shell was pulverized into powdery form and sieved to obtain a particle size of 300 Âľm. Biochemical analysis was carried out to ascertain the types and quantity of proteins present in the cowry shell. The powder was compacted into the different test piece specimen for the different mechanical tests and sintered at 490oC. This was followed by mechanical and chemical characterization of the material. Finally, in-vivo test was carried out to ascertain the materialsâ&#x20AC;&#x2122; biocompatibility with bone cells. Results: The immunoassay results show that the use of cowry shell as bone graft substitute will not present any antigenic interaction that may results in adverse immunological response in the host. The mechanical test also shows that the hardness and compressive strength of the processed cowry shell is comparable to that of other bone graft substitute materials. The material was however very brittle, subsequently limiting its application for load bearing. The in-vivo results, showed integration of the materials with the bone cells at 14th day post insertion. Conclusion: The material was found to be biocompatible with bone cells: Thus affirming the materials suitability as bone graft substitute for bone repair and replacement. (J Osteol Biomat 2012; 1:21-27)

Keywords: cowry shell, bone graft substitute, hardness, compressive strength, osseointegration and biocompatibility.

1 Department of Materials Science and Engineering, Faculty of Technology, Obafemi Awolowo University, Ile Ife, Nigeria 2 Department of Restorative Dentistry, Faculty of Dentistry, College of Health Sciences, Obafemi Awolowo University, Ile Ife, Nigeria 3 Department of Child Dental Health, Faculty of Dentistry, College of Health Sciences, Obafemi Awolowo University, Ile Ife, Nigeria 4 Department of Oral/Maxillofacial Surgery & Oral Pathology, Faculty of Dentistry, College of Health Sciences, Obafemi Awolowo University, Ile Ife, Nigeria 5 Department of Hematology and Immunology, Obafemi Awolowo University, Ile-Ife., Nigeria 6 Department of Chemistry, University of Agriculture, Abeokuta, Nigeria

Correspondence to *Oyatogun Grace. M., Department of Materials Science and Engineering, Faculty of Technology, Obafemi Awolowo University, Ile Ife, Nigeria +234-8037524422. E mail: oparinde@oauife.edu.ng

INTRODUCTION The treatment of bone fracture, bone disease, bone repair and bone replacement is so prevalent that every year, over one million people in the U.S. alone require bone graft procedures, particularly jaw bone replacement, while over 500,000 patients require dental implants worldwide1-2. Most often these implants are made from metallic materials such as titanium based alloys, or alloys made from cobalt and chromium, etc. However, these materials fail due to adverse immunological response, inflammatory responses, infection, and implant loosening, which result in regular dental replacement surgeries being performed to replace these failed implants2-6. To address the problems highlighted above the use of biological grafting techniques, such as autograft, allograft and xenograft were adopted. These were however found to be fraught with diverse limitations such as morbidity of the donor site, suitability of donors, the need for life long immuno-suppressant treatment and susceptibility to infection and diseases5,7. Consequently, the need for other methods and materials that would properly replace damaged bones, reducing the multiple and extended surgical procedures and trauma.

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Material that would successfully serve as a bone substitute must be highly biocompatible and similar in composition to bone, to enhance osseointegration, prevent inflammatory responses, and limit the possibility of implants failure by loosening1, 5, 8-14. Cowry shell is a natural composite composed of calcium carbonate (CaCO3) in a matrix of chitin, a polysaccharide. Proximate analysis of the shell shows that its major constituent is calcium,15. The possibility of the use of cowry shells as a bone graft substitute is therefore envisaged because of the similarity in its elemental compositions with the human bone. Hence this work attempted to process and characterizes cowry shell to verify its suitability as a possible bone graft substitute for dental and orthopaedic applications. MATERIALS AND METHODS Sample Preparation Perforated cowry shells were thoroughly washed to remove sand, dust, dirt and insect larva. The clean shells were subsequently oven dried at 80oC for 20 minutes to remove moisture. The dried shells were pulverized and screened to a particle size of 300 Âľm. Some of the pulverized shells were compacted into a cylindrical form using hydraulic mounting press and some were compacted into moulds already designed for tensile test specimen. The compacted cowry samples were sintered in the furnace at a sintering temperature of 490oC. These samples were utilized for the mechanical characterization of the processed material.

Journal of Osteology and Biomaterials

Table 1. XRD Spectrum Data for Cowry 2θ 19.15 19.50 20.45 21.02 21.30 22.33 23.00 23.24 23.52 24.26 24.99 25.16 25.64 26.28 27.42 28.19 28.94 29.61 30.65 31.57 32.02 32.84 33.19 33.42 33.63 34.17 35.33 36.51 37.16 37.55 38.11 38.54 38.98 39.15 39.46 40.07 40.61 40.97 41.14 41.33 41.60

D spa 4.63406 4.55235 4.34309 4.22607 4.17160 3.98098 3.86654 3.82659 3.78195 3.66833 3.56333 3.53874 3.47369 3.39078 3.25284 3.16577 3.08548 3.01673 2.91636 2.83413 2.79509 2.72690 2.69903 2.68095 2.66451 2.62402 2.54074 2.46128 2.41948 2.39534 2.36100 2.33572 2.31048 2.30079 2.28357 2.25007 2.22145 2.20290 2.19390 2.18445 2.17103

I int 110 64 71 103 142 69 290 158 151 1639 599 776 228 75 67 129 156 74 945 112 57 89 381 552 678 345 887 209 84 89 174 225 102 95 102 446 213 103 114 150 107

I max 2.8 1.6 1.8 2.6 3.6 1.8 7.4 4.0 3.9 42.0 15.4 19.9 5.8 1.9 1.7 3.3 4.0 1.9 24.2 2.9 1.5 2.3 9.8 14.2 17.4 8.8 22.7 5.4 2.1 2.3 4.5 5.8 2.6 2.4 2.6 11.4 5.5 2.6 2.9 3.9 2.7

I rel 6.7 3.9 4.3 6.3 8.6 4.2 17.7 9.6 9.2 100.0 36.6 47.4 13.9 4.6 4.1 7.9 9.5 4.5 57.7 6.8 3.5 5.4 23.2 33.7 41.4 21.1 54.1 12.8 5.1 5.4 10.6 13.8 6.2 5.8 6.2 27.2 13.0 6.3 7.0 9.2 6.5

I corr 7.7 4.4 4.8 6.8 9.3 4.4 18.1 9.8 9.4 100.0 36.1 46.6 13.5 4.4 3.8 7.4 8.8 4.2 52.4 6.2 3.1 4.8 20.6 29.8 36.5 18.5 47.1 11.0 4.4 4.6 9.1 11.7 5.3 4.9 5.3 22.9 10.9 5.3 5.8 7.7 5.4

Fwhm 0.521 0.521 0.521 0.521 0.521 0.521 0.521 0.521 0.521 0.521 0.521 0.521 0.532 0.539 0.539 0.539 0.539 0.539 0.539 0.539 0.538 0.538 0.538 0.538 0.538 0.538 0.537 0.536 0.536 0.535 0.534 0.533 0.532 0.532 0.531 0.530 0.529 0.528 0.528 0.527 0.527


Oyatogun G. M. et al.

Immuno-Assay Test The protein present in the cowry was extracted with phosphate buffered saline (PBS) at a pH of 7.5. The extract was used to verify the type and concentration of proteins that might be present in the cowry shell using the Kjedahl and Bradford method respectively. In addition, haemagglutination test using 2% human erythrocytes (red blood cells) of groups A, B and O was carried out to verify the lectin activity of the material. Extract was also used to immunize rabbits, using established protocols, for 12 weeks. Serum of immunized rabbits (antiserum) was reacted against the protein extracts in Ouchterlony double immuno-diffusion test, to study the immunological response, which might have been triggered by the material. Elemental Analysis Chemical analyses of the samples were carried out using the Debye-Scherrer, XRD powder technique. The materials, in their pulverized forms, were subjected to CuKÎą radiation with an exposure time of 1200/1200 seconds using the MD-10 mini diffractometer. Mechanical Characterization Mechanical tests were carried out to verify the mechanical properties of the material. The tests carried out include; hardness test, compressive test and tensile test. Hardness test: The compacted cowry and chitosan were subjected to Vickers hardness test after sintering at the temperature of 490oC and 215oC respectively. The planar surfaces of the samples were polished with 1-micron diamond solution to obtain smooth surfaces. A load of 50 kg-f was applied

23

Figure 1. XRD Spectrum of Cowry Shell

Figure 2. Compressive Strength of the Coimpacted Cowry Shell

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CI

CI Figure 3. Photomicrograph of a section of tissue showing bone formation (Arrow) around Cowry shell based implant â&#x20AC;&#x201C;CI, (a) 14 Days Post-Operation, (b) showing the implant also exbiting lacunae containing osteocytes 21 Days Post-Operation H&E x 100]. on the chitosan while 60 kg-f was applied on the cowry shell for 15 seconds. The resulting impression observed was measured under a microscope. The Vickers hardness value VHV for the material was calculated using Equation 1. (Where P is the applied load and D is the diameter of impression) Compressive and tensile test: The compacted samples, after sintering, were subjected to compression test using the Instron universal testing machine to determine the compressive strength of the materials. Similarly, the tensile test samples were subjected to tensile test using the Instron testing machine. In-vivo test: The interaction of the materials with the bone cells was studied after insertion of the cowry shell into the jaw bone of four mice. The mice were sacrificed at 14th day post operation and 21 days post operation. The specimen were stored in formalin

Equation 1.

Journal of Osteology and Biomaterials

and thereafter processed for histological examination. National guideline for care and use of laboratory animals were observed and the study protocol was approved by Obafemi Awolowo University Ethical Committee.

RESULTS The X-ray diffractometric spectrum for the cowry shell is presented in Fig. 1 and the measured data, which include the Bragg angles and interplanar spacing for the different compounds present in the cowry shell, are shown in Table 1. The Vickers hardness result is presented in Table 2 and the compressive test result for the cowry shell is presented in Fig. 2. The materials however fracture without undergoing any significant plastic deformation when under tensile loading; hence the tensile property of the material could not be measured. Finally the in-vivo results, showing the interaction of the materials with the bone cells, are presented in Fig. 3. Histological examination of tissues, 14 days post-operation, showed that cowry shell based material exhibited osseointegration with evidence of woven bone formation and integration around the implanted materials. There were no intervening soft tissue (fibrosis) between implant and bone. Neither were there inflammatory cell infiltrates in the tissues


Oyatogun G. M. et al.

25

Table 2. Vickers Hardness of Compacted Cowry Shell Sample Cowry

Sintering Temperature (0C)

Applied Load (kg-f)

Diameter of Impression (mm)

Area of Impression (mm2)

Vickers Hardness (VHN)

490

60

0.45

0.159

549

immediately adjscent to the implants. Some of the implants were also beginning to show lacunae containing osteocytes (Fig 3a). At 21days post-operation larger amounts of bone had formed around the implants and some implants had become entirely filled with lacunae containing osteocytes (Fig 3b).

DISCUSSION The immuno assay test results shows that the protein extract from the cowry shell was found negative against lectin activity. In addition, the Ouchterlony double immuno-diffusion test revealed there was no reaction between the extract and the mice serum. Finally, analysis of extract with Kjedahl method showed that the protein content was 1.9097%, signifying that the material has little or no protein in it. Hence it may be inferred that the use of cowry shell as bone graft substitute will not present any antigenic interaction that may results in adverse immunological response in the host. One of the basic applications of Debye-Scherrer, powder method, is the identification of unknown crystalline phases present in a material based on the fact that each crystalline material has its own characteristics set of interplannar spacings and Bragg angles. Identification of an unknown crystalline phase in a metal can be made by a careful matching of the powder pattern Bragg angles and reflected intensities of the unknown substance with those in the diffraction data index16. The XRD spectrum of the pulverised cowry shell, through the predominant peaks, shows the presence of the different compound, or phases, present in the sample: The spectrum revealed the presence of traces of K, Na, Al, Fe, Mn and silicate in the cowry shell, these elements are found in the physi-

ological system and would therefore not impair the biocompatibility of the material. The highest peak was however located at 2θ equals 24.26° and when this was cross referenced with a number of compounds in the X-ray Diffraction Data Index Database the best fitted compound was calcium carbonate (Fig. 1). This shows that the predominant compound in the shell is calcium carbonate and corroborates the findings of Oloyede15. Bone is a natural composite made up of matrix of collagen (polymer) reinforced with approximately 69% volume fraction of calcium phosphate (ceramic) nanometre-scale crystals, 9% of water and small quantities of other organic materials, such as proteins, polysaccharides, and lipids9. Thus, the similarity in the composition of the material with that of bone can be noted. This would no doubt enhance the adsorption, adhesion and proliferation of bone cells on the material, consequently enhancing the integration of the material with the bone cells. Analysis of the Vickers hardness results shows that the Vickers hardness value for compacted cowry is 549 VHN, see Table 2. This value is in the range of the hardness value of hydroxyapatite, which has been used clinically in different applications such as middle ear implants, alveolar ridge reconstruction and augmentation, in porous form as granules for filling body defects in dental and orthopeadics surgery and as a coating on metal implants10, 17- 19. Fur-

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Oyatogun G. M. et al.

thermore, the result of the compressive test gave a compressive strength value of 1.4 MPa, which also fall within the values of some of the materials used in orthopedic and dental implant10 ,17. Hence it may be inferred that the material can be used as bone graft substitutes for bone repair and replacement. The tensile test however shows that the material is rather brittle and may not be sultable for laod bearing applications. The in vivo test result also confirms the suitability of the materials for bone repair and/or bone substitute. Histological examination of tissues at 14 days and 21 days post-operation, showed that cowry shell based material exhibited osseointegration with evidence of woven bone formation and integration around the implanted materials. This formation of a direct interface between implant and bone, without intervening soft tissue showed that the Cowry shell based implant had integrated well with the bone.

Journal of Osteology and Biomaterials

CONCLUSSION Although researchers have worked extensively on dental and orthopaedic implant6, 13-14, 18- 25, this study provides an insight in the fact that processed cowry shell is a suitable material for the production of bone substitute material: in view of the fact that it has been found to have satisfactory biocompatibility, osseointegration and adequate mechanical properties.


Oyatogun G. M. et al.

REFERENCES

plantation bed. J Biomed Mater Res 1998; 19: 251.

1. Suchanek W, Yoshimura M. Processing and Properties of Hydroxyapatite- based Biomaterials for Use as Hard Tissue Replacement Implants. Journal of Materials Research 1997; 13: 94-117

15. Oloyede OI. Chemical Constituent of Cowry (Cyparica Samplomoneta). Pakistan Journal of Nutrition 2008; 7:540-542.

2. Giannoudis PV, Dinopoulos H, Tsiridis E. Bone Substitutes: An Update, Injury. Int J Care Injured 2005;365: 20-27 3. Weiss P, Obadia L, Magne D, Bourges X, Rau C, Weitkamp T, et al. Biomaterials 2003;24: 4591-4601. 4. Porter AE, Patel N, Skepper JN, Best SM, Bonfield W. Comparison of in vivo dissolution processes in hydroxyapatite and silicon-substituted hydroxyapatite bioceramics. Biomaterials 2003;24:4609-4620.

16. Reed-Hill RE. Physical Metallurgy Principles. Van Nostrand Company. NY. 1973; 46- 51. 17. Reilly DT, Burstein AH. The elastic and ultimate properties of compact bone Tissue. J Biomechanics 1975; 8: 393-405. 18. Lazic S, Zec S, Miljevic N, Milonjic S. The effect of temperature on the properties of hydroxyapatite precipitated from calcium hydroxide and phosphoric acid. Thermochim Acta 2001; 374:13-22. 19. Man and Mollusc, 2010, http://www. manandmollusc.com.

5. Binon PP. Treatment planning complications and surgical miscues. J Oral Maxillofac Surg 2007;65:73-92.

20. James RA. Host response to dental implants. In biocompatibility of dental materials, CRC Press, Boca Raton, FL, 1982;163.

6. Lancefleld WR, Hench LL, The bonding of Bioglass速 to a cobalt-chromium surgical implant alloy. Biomaterials 1986;7: 104-108.

21. Ratner BD, Hoffman AS, Schoen FJ, Lemons JE. Biomaterials science, an introduction to materials in medicine, 2nd edition. Elsevier Academic Press, San Diego. 2004;162

7. Hench LL, Paschall HA. Histochemical responses at a biomaterials interface. J Biomed Mater Res 1974; 5: 49-54. 8. Kumari TV, Vazuelev U, Kumari A, Menon B. Cell surface interactions in the study of biocompatibility. Trends Biomater and Artif Organ 2002;16:37-41. 9. Hench LL, Wilson J. Bioceramics. MRS Bulletin 1991; 62-74. 10. Gibson P. Microstructure and Mechanical Property of human tooth. J Biomed Mater Res 1985;75:128-134. 11. Elbjeirami WM, Yonter EO, Starcher BC. Ehancing mechanical property of tissue engineered constructs via lysyl oxidase crosslinking activity. J Biomed Mater Res 2003;66:513-521.

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22. Brunski JB. Biomechanics of oral implants: Future research directions. J Dent Ed. 1988; 52: 775-778. 23. Burdinski K. Engineering Materials, properties and selection. 5th Ed. prenticeHall, Old Tapan, NJ, 1995. 24. Wang M. Developing bioactive composite materials for tissue replacement. Biomaterials 2003; 24: 2133-2151. 25. Katti KS. Biomaterials in total joint replacement. Colloids and Surfaces 2004;39: 133-142.

12. Jones RJ, Hench LL. Regeneration of Trabecular Bone Using Porous Ceramics. Current Opinion in Solid State & Materials Science 2003; 7:301-307. 13. Hench LL, Julian R, Jones RJ, Jefrey K. Bonding mechanisms at the interface of ceramic prosthetic materials. J Biomed Mater Res 2005;2: 117-141. 14. Agrawal V. The interface of various glasses and glass-ceramics with a bony im-

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Original article

Projecting cranial capacities using vertebral foramina circumferences Elizabeth Celata

The human spine, in particular the vertebral foramina, can be used to determine the approximate cranial capacity of a Homo sapiens specimen. This approximation is possible due to the relationship between the spinal cord and the brain. A formula for estimating cranial capacity was proposed based upon a number of ratios. These basic ratios include the circumference of the cranium, from the occipital lobe to the frontal lobe; the crest of the skull to the palate; and the circumference of each vertebral space. Understanding the ratio within Homo sapiens sapiens could enable us to make predictions about our ancestors and the process of evolution within our species. (J Osteol Biomat 2012; 1:29-43)

Key words: vertebral, foramina, formula, cranial, capacity

Corresponding author: Elizabeth Celata 42 Aldwick Rise Fairport, NY 14450 (585) 360-6182 celatae@hartwick.edu

INTRODUCTION Evidence of the volume of the cranium is built into the structure of each vertebra as the vertebral foramina cradle the spinal cord. An example of a vertebral foramen is shown using the Atlas vertebra in the picture to the right (Figure 1.). The biological connections between the brain and the off-shooting nerves that travel down through the vertebral foramina make it plausible that a formula that is dependent on vertebral circumferences could predict the size of a specimenâ&#x20AC;&#x2122;s cranial capacity. This formula would be based on a ratio of four major circumferences: transverse cranial, sagittal cranial, coronal cranial and transverse vertebral. The ratio of these four circumferences could be utilized to estimate cranial capacity with some accuracy even when the skull is absent as the following research shows. The hypothesis tested here is that a relationship exists between the circumference of the vertebral foramina and the cranial capacity. Although the spine and the cranium have both been studied, this major connection between the two has not been previously discussed; therefore, there is a general lack of source material that connects the vertebral foramen and cranial capacity. The data

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Elizabeth Celata

Vertebral foramen

Figure 1. Vertebral foramen

and the mathematics within this paper are solely derived from the research described within this article. All figures, tables, and methods were created or were repurposed such, as the ellipsoid formula, to work within the boundaries of this research. MATERIALS AND METHODS The cranial capacities of the specimens utilized in this research were determined in two manners: via displacement and via measurements made directly to the skull. The difference between the capacities found through both methods averaged less than one percent. The cranial capacities found through the use of the vertebral foramina were compared to those received via displacement and measurement to further ensure their accuracy. Twenty-five specimens were used from the Hamann-Todd Collection at the Museum of Natural History in Cleveland, Ohio. Additionally, there were three specimens from the Anthropology Department at Hartwick College Oneonta, New York, which were used to outline the basic process of mathematical analysis. To determine which specimens would be part of the sample size from the Hamann-Todd collection, a random number generator was utilized to determine which specimens were used.

Journal of Osteology and Biomaterials

Of the twenty-five specimens from the tested against displacement values. All Hamann-Todd Collection, five females three radii are labeled for visual referof African origin were included with ence in the above picture (See Figure ages ranging from twenty-four to sev- 2., France 2004:68). The base of the enty-two years of age.1 The majority of ratio was either coronal or transverse The circumferences were measured using measuring tape, and each measurement was the specimens were Caucasian males. due to the ease of measurement and three times The three placed in an factcranial thatmeasurements the two were measurements There weretaken fifteen within order theirto assure ages accuracy. at the ellipsoid brain’s shape death falling in a formula rangeasofthetwenty-two Sagittal
(c) Coronal
(b) to sixty-fivemost years old. The sample also closely relates to an ellipsoid rather included four Caucasian females rangthan a spherical form. The ellipsoid Transverse
(a) Transverse
(a) ing from twenty-five to forty-nine years formula is: 4/3πabc. The “a” within the old. The age ranges of the specimens formula represents the transverse radius were generally good except for males shall be determined from the of African that descent as there was only circumference measured as will one male specimen ofmanually African descent Figure 2. who was thirty years old his radius timewill be “b.” The final value “c” is the sagittal radius which the coronal radius. The at coronal were the largest. of death. The results shouldinto not was directly determined ratiohave format through a digital approximation that was then tested With each specimen of the twentybeen influenced by sexual dimorphism against displacement values. All three radii are labeled for visual reference in the above picture five from the Hamann-Todd Collection, as 64% of specimens used were male (SEE Fig. 2, France 2004:68). The base of the ratiocoronal was either value coronal or transverse due toby the the the was divided whereas 36% were female. Ethnic oritransverse vice versa in order to ease of measurement and the fact that the two measurementsand were the largest. gin was split, with 24% being of African determine which was the most stable With76% each were specimen the twenty-five from the Hamann-Todd Collection, the coronal ethnic origin while ofofCaucabetween all twenty-five specimens. value was divided by the transverse and vice versa in order to determine which was the most sian descent. Therefore, the coronal value was choThe circumferences were measured us- Therefore, the coronal value was chosen as the base stable between all twenty-five specimens. sen as the base for the ratio. Thus, the ing measuring tape, measurefor the ratio. and Thus,each the coronal circumference gained the value of 1 within the ratio whereas the coronal circumference gained the value ment was taken three times in order transverse circumference gained the value ofof 1.1.1As related the to theratio coronal ratio value the of 1, transthe within whereas to assure accuracy. The three cranial circumference gained the value sagittal was found to be .83333333333. The verse coronal appeared to be more stable and produced the measurements were placed in an ellipof 1.1. As related to the coronal ratio 1:1.1 (coronal: transverse) ratio with only a few exceptions rather than the multitude of soid formula as the brain’s shape most value of 1, the sagittal was found to be alterations due torather the general irregularity of the transverse value in comparison to closely relates to that an occurred ellipsoid .83333333333. The coronal appeared the sagittal.form. Due to the limitations of cranial measurements and the ellipsoid shape of the brain than a spherical The ellipsoid to be more stable and produced the formula is: 4/3πabc. The “a” within 1:1.1 (coronal: transverse) ratio with 5 the formula represents the transverse only a few exceptions rather than the radius that shall be determined from multitude of alterations that occurred the circumference manually measured due to the general irregularity of the as will the coronal radius. The coronal transverse value in comparison to the radius will be “b.” The final value “c” is sagittal. Due to the limitations of crathe sagittal radius which was directly nial measurements and the ellipsoid determined into ratio format through shape of the brain that does not allow a digital approximation that was then calculation of the axis backwards from

Exact ages are available upon request if they are not stated within the article. The ‘exact ages” are the absolute ages which were recorded at each individual’s death.

1

circumference, calculating axis length was done working backwards with the


Elizabeth Celata

formula C = π*d. Two of the three cranial circumferences were easily taken, which were the coronal and transverse, but the sagittal proved to be difficult as it would involve destruction of the skull if it were to be taken manually. The ratio of the sagittal cranial axis and circumference were determined in part from trial and error; however, a general estimation was formed through the use of a digital approximation when compared with the frontal view of the cranium. The result went straight to ratio instead of forming separate circumferences due to the fact that it was found through comparison rather than a direct measurement. The cranial capacities gained through displacement were already on file at the Cleveland Museum of Natural History. The capacities found via measurements used the manually determined transverse and coronal circumferences with the sagittal moving through the ratio to gain the cranial capacities via the ellipsoid formula. When compared, there was a less than one percent different on average. The fluid measurements, which were on file at the Cleveland Museum of Natural History, assisted in the confirmation of the sagittal value of the ratio as the cranial capacities found through the measured formula with the approximated sagittal proved to be relatively close to the displacement value. Three vertebrae appeared to be the most accurate in predicting cranial capacity due to the close relation between the ratio of the circumference of those particular vertebrae and the coronal circumference of the skull. These most accurate vertebrae were

C3, T6, and T8. Of all the vertebrae, they had the highest percentage of accuracy falling within a 2.0 range of the correct coronal circumference 14 times out of 21. As they had the highest frequency within the 2.0 range, these three vertebrae were placed into the formula to determine their accuracy at projecting the cranial capacity. Calculating each one’s average percent found that C3 had an average error percentage of 14%, T6 an average variance percentage of 15.39%, and T8 an average error percentage of 18.87%. In total, they have an average error percentage of 16.09%. However, upon going through the method with the first few specimens, it became obvious that the results would produce a higher percentage of error than was desirable. Therefore, this method was abandoned in favor of a multiple measurement method that would allow for more accurate results. A secondary method wherein four vertebrae were selected at random and then placed through the formula with their results being averaged proved to be promising and is the method further utilized in this paper. In theory, the vertebrae available would undergo this method process; however, as all vertebrae were available, four were chosen at random by a random number generator: T3, T4, T7, and T10 which were used for HTH-269. The four vertebrae were then put through the formula to determine the coronal circumference. The coronal circumference was then used to determine the transverse, coronal and the sagittal radii, which were then inserted in the ellipsoid formula, such as in the example below:

31

T3 – Coronal Estimate = 41 Therefore, Transverse = 45 A – 7.16 B – 6.52 C – 5.43 T3 Cranial Capacity = 1061.82 cm³ T4– Coronal Estimate = 43 Therefore, Transverse = 47 A – 7.48 B – 6.84 C – 5.70 T4 Cranial Capacity = 1221.58 cm³ T7– Coronal Estimate = 43 Therefore, Transverse = 47 A – 7.48 B – 6.84 C – 5.70 T7 Cranial Capacity = 1221.58 cm³ T10– Coronal Estimate = 43 Therefore, Transverse = 47 A – 7.48 B – 6.84 C – 5.70 T10 Cranial Capacity = 1221.58 cm³ Average = 1181.64 cm³ The four resulting cranial capacities were then averaged to get the final cranial capacity. After going through with the random number generator and finding the average of a group of four random vertebrae, the total average percentage of error was 9.24%, which is less than all three averages for each vertebra which appeared most frequently within the 2.0 range as the percentage is within 10%. Thus, averaging all available vertebrae for a specimen would result in a close estimate of the specimen’s cranial capacity. When compared with the displacement capacities, the percentage of error was 9.31%, which remains within the desired zone of less than 10%.

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Elizabeth Celata

RESULTS In order to best understand the possibility of a relationship between a specimen’s cranial capacity and the circumference of its vertebrae, the two were separated in an attempt to observe any patterns that might arise in the comparison of vertebrae to vertebrae and between the three cranial circumferences. The specimens used for this early process were the three available at Hartwick College; two were cranial specimens and the third was a vertebral specimen. The process began with a single spinal column of specimen HCPA-7617, which is shown below:

Figure 3.

C1 C2 C3 C4 C5 C6 C7 C8 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 L1 L2 L3 L4

10.5 8.6 7.9 7.8 7.7 7.5 7.2 7.0 6.8 6.5 6.2 5.8 5.7 5.5 5.3 5.3 5.0 4.8 4.6 4.8 5.5 5.8 6.0 6.2

St. -1.9 -.7 -.1 -.1 -.2 -.3 -.2 -.2 -.3 -.3 -.4 -.1 -.2 -.2 NC -.3 -.2 -.2 +.2 +.7 +.3 +.2 +.2

Journal of Osteology and Biomaterials

Specimen: HCPA-7617 The leftmost column is the position of the vertebra in the spinal cord. The middle column is the circumference of said vertebra in centimeters. The column furthest to the right is the difference between the vertebra and the one preceding it (Fig. 3). It is possible that a relationship exists between the vertebral space and the number of nerves that leaves the spinal cord and ventures out into the rest of the body at each point. Therefore, it is unlikely that there is a concise relationship that can readily be interpreted. This, however, does not mean that it is impossible for a relationship to exist between cranial size and circumference of the vertebrae. The two following specimens (HCPA7420 and HCPA-2356) were taken to assist in ascertaining the ratio between the three cranial circumferences when vertebral consideration is removed (Fig. 4).

If (1.1:1:.83333333) ratio: CPC should be approximately 46.4 centimeters with the axis being 14.7695787… (14.8). B would then be 7.4. Therefore, C would be 6.166666666666...42 (6.17). The Cranial Capacity would then be 1558.70203283… (1558.70cm³). If utilizing unrounded ratio: CPC should be approximately 46.67926078028… (46.7). the axis should then be 14.8584701861167… (14.86). Therefore, B would be 7.429… or 7.43 and C would be 6.191… or 6.19. The Cranial Capacity would then be 1565.02109513… (1565.02cm³). The full process of analyzing a specimen is shown in Figure 5 using the initial specimen (HTH-730) taken from the Hamann-Todd Collection. Specimen: HTH-730 (Fig. 5) The first specimen taken at the Cleveland Museum of Natural History and was a Caucasian male, age 54 at his time of death.

Figure 4.

Specimen: HCPA- 7420 Frontal-Occipital Circumference (cm) Crest to Palate Circumference (cm)

48.7 44.4

FOC/CPC = 1.0968468468468468468468… (1.10: 1) CPC/FOC= .91170431211498973305954825462012… (.91:1) FOC approximate axis length ≈ 15.50169145… (15.5) FOC radius ≈ 7.75 CPC approximate axis length ≈ 14.13295894… (14.1) CPC radius ≈ 7.05 C ≈ b (.8333333333…) ≈ 5.874999999999999999765 (5.87) Cranial Capacity = 4/3πabc ≈ 4/3π (7.75) (7.05) (5.87) ≈ 1343.43769565827648 76671609586701 (1343.44 cm³) Specimen: HCPA-2356 Frontal to Occipital Circumference (cm) Crest to Palate Circumference (cm) FOC approximate axis ≈ 16.233804… (16.2) FOC radius ≈ 8.1 Cranial Capacity = 4.3πabc ≈ 4/3π (8.1) (B) (C)

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Figure 5.

Vertebrae C1 C2 C3 C4 C5 C6 C7 C8 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 L1 L2 L3 L4

Circ. 9.3 7 6 5.8 5.9 5.9 5.8 5.4 5.3 5.2 5.3 5.4 5.4 5.3 5.2 5.5 5.4 5.2 5.9 6.4 6.5 6.4 7.3 6.8

Frontal-Occipital Circumference (cm) Crest to Palate Circumference (cm)

Dif. St. -2.3 -1 -0.2 0.1 0.0 -0.1 -0.4 -0.1 -0.1 0.1 0.1 0.0 -0.1 -0.1 0.3 -0.1 -0.2 0.7 0.5 0.1 -0.1 0.9 -0.5 47 42

FOC/CPC = 1.119047619047619047619… (1: 1.1) CPC/FOC= .89361702127659574468085… (1: .89) There is a change in the CPC/FOC but the FOC/CPC remains the same when rounded to the first decimal place. FOC approximate axis length ≈ 14.96056… (15.0) FOC radius ≈ 7.50 CPC approximate axis length ≈ 13.36901… (13.4) CPC radius ≈ 6.70 C ≈ b (.8333333333…) ≈ 5.58333… (5.58) Cranial Capacity = 4/3πabc ≈ 4/3π (7.50) (6.70) (5.58) ≈ 1174.515829… (1174.52 cm³)

33

The Cranial Capacity is within human range (1000 cm³ - 1800 cm³) but is below the average range (1300 cm³ - 1500 cm³). It is below average by only 125. 48 cm³ and the capacity is within the human range, so it was included in the study. C6 – 5.9 / .13 = 45 5.9/.14 = 42 The table below shows the estimated circumference from crest to palate. The ones highlighted in red round to the exact value. The ones in bright yellow deviate by 1.0 and the ones in goldenrod deviate by 2.0. This is the first of the three that had no exact matches upon rounding. Whether this is due to the skull being an outlier or due to some fault in measurement is uncertain. With this specimen, C3 to C7 are the best examples with none in the second range. C3, C5, and C6 were 1.0 away upon rounding. C4 and C7 were 2.0 away. Though these results will be taken into general account, I put less weight when comparing them to the Table 1. 41.3793103448276 40 40.6896551724138 40.6896551724138 40 46.9565217391304 46.0869565217391 45.2173913043478 46.0869565217391 46.9565217391304 46.9565217391304 46.0869565217391 45.2173913043478 47.8260869565217 46.9565217391304 45.2173913043478

C3 C4 C5 C6 C7 C8 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10

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18 with exact matches. I will use HTH730 to demonstrate the process using the three vertebrae that had the most results throughout the specimens that fell within the 2.0 range (Fig. 6).

Figure 7. C3 – CPC Rounded = 41 Therefore, FOC =45.1 A – 7.18 B – 6.53 C – 5.44 C6 Cranial Capacity Estimate – 1068.38 cm³ C7 – CPC Rounded = 40 Therefore, FOC =44 A – 7.00 B – 6.37 C – 5.31 C7 Cranial Capacity Estimate – 991.79 cm³ T10 – CPC Rounded = 45 Therefore, FOC =49.5 A – 7.88 B – 7.17 C – 5.97 T10 Cranial Capacity Estimate – 1412.89 cm³ T6 – CPC Rounded =46 Therefore, FOC =50.6 A – 8.05 B – 7.32 C – 6.10 T6 Cranial Capacity Estimate – 1505.65 cm³ Ave – 1244.68 cm³

Figure 6. HTH-730 Actual Cranial Capacity - 1174.52 cm³ C3 – CPC Estimate = 41.4 Therefore, FOC = 45.54 A – 7.25 B – 6.60 C – 5.50 C3 Cranial Capacity = 1102.38 cm³ The C3 estimate is off by 72.14 cm³, leaving the estimate off by 6%. T6 – CPC Estimate = 46.1 Therefore, FOC = 50.7 A – 8.07 B – 7.34 C – 6.12 T6 Cranial Capacity = 1518.48 cm³ The T6 estimate was off by 343.96 cm³, leaving the estimate off by 29%. T8 – CPC Estimate = 47.8 Therefore, FOC = 52.6 A – 8.37 B – 7.61 C – 6.34 T8 Cranial Capacity = 1691.56 cm³ The T8 estimate was off by 517.04 cm³, which is off by 44%. Average Cranial Capacity = 1437.47 cm³ (off by 22%) As there is no exact measurement, I took four different results and calculated each ones Cranial Capacity and then averaged them to see if that will result in a close estimation of the actual Cranial Capacity (Fig. 7). I used a random number generator, as stated above, to determine which vertebrae to use.

Journal of Osteology and Biomaterials

The average is more than the actual Cranial Capacity by 70.15 cm³, which makes it off by 5%. I will attempt this with the other two who have no exact numbers as HTH-730 has the least that fall within the 2.0 range of the three that have no exact matches. Thus far, averaging four vertebrae to receive a general estimate seems to be a plausible manner of estimation2. 2

For the rest of the specimens, the full length analysis is available as Appendixes 1-24.

Although the majority of specimens maintained the 1:1.1 ratio, there were some that had a greater difference between their transverse cranial circumference and their coronal cranial circumference. The specimens with ratios of 1:1.2 are HTH-1558, HTH-908, HTH1324, and HTH-1367. The specimens do not seem to have much in common as all had different cranial capacities compared to displacement or manual measurements. HTH-1558 was a female of African origin who was twenty-four years of age whereas HTH-908 was a male of Caucasian ancestry who was thirty-eight years of age. Three of the four were female, and two of the four were of African heritage. The ages for all four are varied, from twenty-four to seventy-two with two in-between at thirtyeight and forty-nine. The four that were not Metopic were included in the rest of the mathematical analysis, and all fit within one and a half standard deviations of the mean. However, HTH1558 and HTH-908 were the greatest distance above the mean save for one point3 that appeared to be outlying continuously; however, the point could not be removed as it fell within three standard deviations. The ratio of 1:1.1 was kept as the majority fell within it without difficulty. From there, the comparison was made to estimate that the sagittal would be .83333333333 due to the comparisons and trial/error testing. The separate circumferences were generally circles, so to gain the radii they were divided by pi and then by two to get the estimated radius (Fig. 8). This point came from specimen HTH-1556.

3


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Figure 8. Transverse approximate axis length ≈ 15.2788… (15.3) Transverse radius ≈ 7.65 Coronal approximate axis length ≈ 13.6873… (13.7) Coronal radius ≈ 6.85 Sagittal radius ≈ b (.8333333333…) ≈ 5.7083… (5.71)1 All sample mathematical material is taken from that done to specimen HTH-269.

1

Figure
9

The resulting radii were then inserted into the ellipsoid formula to gain a measured cranial capacity: Cranial Capacity = 4/3πabc ≈ 4/3π (7.65 cm) (6.85 cm) (5.71 cm) ≈ 1253.3625 cm³. The cranial capacities were the rounded to the sixth significant figure: 1253.36 cm³. The vertebral circumferences and cranial circumferences were measured in centimeters. The differences between the vertebral circumferences for each specimen were taken to determine a pattern of increase and decrease to see if there were sections of vertebrae that would be best suited for use within the hypothesized ratios. These were then charted and clearly showed areas which would later be the main two focus areas for the ratios. The general pattern was the same with a quick decrease followed by minor periods of increase within an overarching decrease with a final increase period at the end (Fig. 9). The main focus of the line graph was to determine if there was a section or multiple sections in which there was a tight clustering, or a period where the range remained approximately the same for an extended period of time. Resulting from these charts, there are two sections with two different comparative numbers, .115

Figure 9. This line graph is Figure 3 put into a graphical format alone with the same tables of differences found for each specimen. The table showed the presence of two areas in which the rate was general even. These areas would be the vertebrae that would work best within the formula method.

and .145, which can be most easily entered into the ratio. The sections were C3-C7 as .145 and C8-T10 as .115. In both sections of vertebrae, the majority of points surrounded the area, or the points were closest to the number provided for those sections. The resulting cranial capacities were then compared with the cranial capacities that were originally taken using the displacement method. The cranial capacities as determined via displacement were subtracted from those found through measurement. The differences were divided by the displacement to determine the percent of error; the average of all those percentages was determined to be .041%. For further results through mathematical and graphical understanding, fluid and measured cranial capacities will be compared to the vertebral cranial estimations that work backwards from the

vertebral foramen. The vertebral-cranial estimations were compared first to the cranial capacities found via measurements and then to the displacement measurements (Table 2). The tables show the possibility of an outlier; however all points fall within three standard deviations. Therefore, the point, which results from specimen HTH-1556, cannot be removed (Table 3). The cranial capacities found via the measurements when compared to those found via the vertebral-cranial ratio have a general range of -.244% to .303%. The majority of the data points, however, fall within the range of -.08% to .15%. The average difference when compared to measurements was .032% with a standard deviation of .117% (Figure 10). HTH-690 and HTH-1556 are both more than one and a half deviations from the mean. HTH-690, however, fell within

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Table 2. Method Comparison Specimen Displacement CC HTH 0069 1333.8 HTH 0306 1242.5 HTH 0385 1504.8 HTH 0609 1662.4 HTH 0650 1328.3 HTH 0668 1201.2 HTH 0670 1460.4 HTH 0672 1366.9 HTH 0690 1221.6 HTH 0707 1376.4 HTH 0730 1162 HTH 0867 1368.5 HTH 0908 1490.4 HTH 0969 1441.1 HTH 1324 1356.8 HTH 1367 1098.6 HTH 1486 1366.1 HTH 1556 1532.8 HTH 1558 1259.5

Measured CC 1359.01 1223.54 1543.1 1710.74 1277.94 1310.78 1419.08 1296.28 1093.57 1348.47 1174.52 1337.94 1359.86 1376.1 1213.41 1359.86 1505.91 1501.93 1090.49

Difference -25.21 18.96 -38.3 -48.3399999999999 50.3599999999999 -109.58 41.3200000000002 70.6200000000001 128.03 27.9300000000001 -12.52 30.5599999999999 130.54 65 143.39 -261.26 -139.81 30.8699999999999 169.01

Table 3. Comparing Displacement and Measured to Vertebral Cranial Capacities Difference (Displacement) Percent Error Difference (Measured) -57.02 -0.0428 -70.1600000000001 134.32 0.108 14.98 -171.81 -0.114 248.08 257.35 0.155 168.3 -21.1400000000001 -0.0159 79.88 -29.75 -0.0248 -266.92 209.62 0.144 -123.49 39.4100000000001 0.0289 455.36 -138.89 -0.114 166.53 132.43 0.096 -66.98 -82.6800000000001 -0.0711 305.69 45.54 0.0333 104.5 297.07 0.199 -31.21 -58.49 -0.0406 -31.8099999999999 76.4099999999999 0.0563 79.8299999999999 -94.73 -0.0862 -133.51 -60.0600000000002 -0.044 79.75 486.23 0.317 -71.5 248.89 0.198 71.7199999999998 115.36 12.6099999999999

Journal of Osteology and Biomaterials

Percent -0.0189 0.0153 -0.0245 -0.0291 0.0379 -0.0921 0.0283 0.0517 0.105 0.0203 -0.0108 0.0223 0.0876 0.0451 0.106 -0.238 -0.102 0.0201 0.134

Percent Error -0.059735040697476 0.0111963167257127 0.158834225420647 0.118597964878654 0.0732514741079698 -0.244081311667292 -0.089739117796671 0.303183237567663 0.122461135705146 -0.055199808803289 0.178688754574044 0.0774952353407936 -0.024076588391396 -0.023406744615565 0.0609026686400463 -0.086520640269587 0.0529580120989966 -0.055949418595552 Fig. 130.0572221867619836 0.09428379946712 0.009273013398438


S P E C I M E N S

Figure
10

Percentage
of
Error

Elizabeth Celata

S P E C I M E N S

Figure
11

Percentage
of
Error

Figure 10. The data points shown in Table 2 placed upon a graph to show outliers and ranges. The first standard deviation is shown in yellow; the range of one and a half deviations is show by the orange lines, and the green circles surround points within three standard deviations that are generally outlying in comparison with the rest of the points. The red line is the average - .32.

Fig. 11. The data points shown in Table 3 placed in graphical form to show outlier and ranges. The first standard deviation is outlined in orange with the area where the two ranges meet as the average of .041. One and a half deviation marks, meaning between the end of the first and halfway through the second deviation, is outlined in blue. The single outlying point is circled in green.

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one and a half deviations when compared to the cranial capacities as determined via displacements. The range of the vertebral-cranial ratio error is -.114% to .317% with -.08% to .16%. The average mean when compared to the displacement capacities is .041% while the standard deviation is .121% (Figure 11). HTH-1556 falls within three standard deviations, and it is the only one that was beyond one and a half standard deviations of the mean. The cranial capacities measured via displacement have a similar range as the same specimen’s capacities as estimated through circumferences. However, the displacement capacities also only have one outlier whereas the measured cranial capacities have two that fall outside of the one and a half deviations away from the mean. This shows that the vertebral foramen circumferences as processed through the formula produce a generally tighter cluster of data when compared with the more accurate cranial capacities. Furthermore, the results support the hypothesis that there is a relationship between the circumferences of the vertebral foramina and a specimen’s cranial capacity. To further determine the relationship between the data, the Measured Cranial Capacities were compared to the Displacement Cranial Capacities (Table 2). A Simple Linear Regression was used at first to compare the two with Measured Cranial Capacities being placed on the y-axis and Displacement Cranial Capacities being placed upon the x-axis. The slope’s range of .44903581.1960706 is too large and far from 1.0 to suggest that the Simple Linear

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Figure 13. Polynomial Regression Results (with no Intercept): Dependent Variable: Measured CC Independent Variable: Displacement CC Variable

Estimate

Std. Err.

DF

95% L. Limit

X

0.9877921

0.01765653

18

0.9506971

Analysis of variance table for polynomial regression model: Source DF SS MS F-stat Model 1 3.45E+07 3.45E+07 3129.8267 Error 18 198183.48 11010.193   Total 19 3.47E+07     Summary of fit: Root MSE: 104.92947 R-squared: 0.9943 R-squared (adjusted): 0.994

Journal of Osteology and Biomaterials

95% U. Limit 1.0248871

Regression is a good fit for the data. As a result, the two cranial capacities were compared using a Polynomial Regression with a degree of 1. By forcing the data to go through the origin, the range was dramatically slimmed, so it became .9506971-1.0248871 (Fig. 13). Thus, the data shows that the correlation between the two sets of data is extremely close to 1.0. As a result, I decided to compare the cranial capacities discovered through the formula process and compare them first to the displacement cranial capacities then to the measured cranial capacities (Table 4). The Displaced Cranial Capacities were once again placed upon the x-axis with the Formula Cranial Capacities taking the y-axis (Fig. 14) The range for the 95% confidence interval between the Formula Cranial Capacities and the Displacement Cranial Capacities is .880102922 – 1.013933596. Although this is a wider range than that of the Displacement Cranial Capacities to the Measured Cranial Capacities, the comparison shows promise as it is still quite close to the 1.0 for which we are looking. The final polynomial regression comparison is that of the Measured Cranial Capacities on the x-axis with the Formula Cranial Capacities being placed upon the y-axis once more (Fig. 15). In all three comparisons, the range of the confidence intervals is close to 1.0; therefore, this supports the correlation between the cranial capacities generated by the formula versus those generated through displacement or measurement. Thus, the polynomial regressions demonstrate that the formula can estimate the cranial capaci-


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ties of specimens accurately with a slim margin of error.

Figure 12. Simple linear regression results: Dependent Variable: Measured CC Independent Variable: Displacement CC Measured CC = 226.41908 + 0.82255316 Displacement CC Sample size: 19 R (correlation coefficient) = 0.748 R-sq = 0.5594389 Estimate of error standard deviation: 105.28111 Parameter estimates: Parameter Intercept Slope

Estimate

Std. Err.

226.41908 241.36903 0.82255316 0.17703792

DF 17 17

Analysis of variance table for regression model: Source DF SS MS Model 1 239274.42 239274.42 Error 17 188429.9 11084.112 Total 18 427704.34  

95% L. Limit -282.82507 0.4490358

95% U. Limit 735.6632 1.1960706

F-stat 21.587152    

P-value 0.0002    

DISCUSSION These ratios can be utilized to discover the cranial capacity of a specimen that includes vertebrae but has an incomplete or absent skull. Knowing the cranial capacity, a general outline for the reforming of the skull can be determined by utilizing the formula for estimations in the three cranial circumferences. Further research could prove that these ratios or similar ratios exist within early hominids and could dramatically alter anthropological understanding of the evolutionary timeline. Alternatively, the very existence of a ratio could change the understanding of the spinal cord and the brain as well as the relationship between them. Additionally, the discovery of the correct ratios could alter academic understanding of the implications of the vertebrae in physical and biological anthropology. Although the collection is generally vast, no Asian American or Native American specimens were available. The use of both ethnic categories as well as specimens from outside the United States of America would assist in providing further support for the formula created through this research. There was only one male of African origin who was thirty years of age. In a study in which this research is duplicated, it would be profitable if the sample were to include a greater number of males of African descent. . A greater variation of ethnic origin is needed to determine whether the formula is appropriate for all populations or if the relation between vertebral foramen circumference and cranial capacity

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Table 4. Specimen HTH 0069 HTH 0306 HTH 0385 HTH 0609 HTH 0650 HTH 0668 HTH 0670 HTH 0672 HTH 0690 HTH 0707 HTH 0730 HTH 0867 HTH 0908 HTH 0969 HTH 1324 HTH 1367 HTH 1486 HTH 1556 HTH 1558

Displacement CC 1333.8 1242.5 1504.8 1662.4 1328.3 1201.2 1460.4 1366.9 1221.6 1376.4 1162 1368.5 1490.4 1441.1 1356.8 1098.6 1366.1 1532.8 1259.5

Measured CC 1359.01 1223.54 1543.1 1710.74 1277.94 1310.78 1419.08 1296.28 1093.57 1348.47 1174.52 1337.94 1359.86 1376.1 1213.41 1359.86 1505.91 1501.93 1090.49

Variable  Estimate Standard Error DF 95% L. Limit 95% U. Limit X 0.947018259 0.031716202 18 0.880102922 1.013933596 Analysis of variance table for polynomial regression model:   DF SS MS F-Stat Model 1 30078343.45 30078343.45 891.567741 Error 18 573519.8967 33736.46451   Total 19 30651863.35    

Journal of Osteology and Biomaterials

Figure 14. Summary of Fit: Root MSE R Square Adjusted R Square

Formula CC 1390.82 1108.18 1676.61 1405.05 1349.44 1230.95 1250.78 1327.49 1360.49 1243.97 1244.68 1322.96 1193.33 1499.59 1280.39 1347.25 1426.16 1046.57 1010.61


Elizabeth Celata

Figure 15. Variable X

Standard Error 0.959163333 0.028894021 Estimate

DF 18

95% U. Limit 0.898202277 1.020124389 95% L. Limit

Analysis of variance table for polynomial regression model:   DF SS MS Model 1 30186182.94 30186182.9 Error 18 465680.4082 27392.9652 Total 19 30651863.35   Summary of Fit: Root MSE R Square Adjusted R Square

165.5082028 0.984807436 0.925983906

F-Stat 1101.968434    

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changes. As previously stated, study of specimens originating from outside the United States as well as those of Asian, Hispanic, and Native American origin from within the United States of America would be profitable if another experiment were to occur. The mathematical calculations utilized with the ellipsoid formula makes estimation of a specimen’s cranial capacity to be not only possible but profitable. With further research utilizing earlier hominids as well as more diverse specimens, the vertebral method could enable anthropologists to have a more accurate understanding of early hominids, which would assist in organizing the evolutionary timeline. However, more research would be necessary to determine whether or not the formula is viable with species other than Homo sapiens sapiens. The discovery of the correct ratios would allow a clarification of the brain size of early hominids and help students understand the implications of the vertebrae in physical anthropology. It is also possible that this formula would be useful for investigations in which the cranium was separated from the torso as it would enable anthropologists to estimate the size and general form of the specimen’s cranium. This research furthers our understanding of the connections between the cranium and the vertebrae. With further research, the formula may be perfected, and other uses may be found for it. In order to determine if it would be appropriate to utilize the formula for ancestors of Homo sapiens sapiens, earlier specimens that were found with the majority of their cranium still intact

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must be tested. Theoretically, the relation between the brain and the nerves should be similar if not the same within early hominids as they are in modern humans. It is possible that the formation of the different lobes of the brain contributed to an alteration in the ratios. The same can be stated about other primates and other vertebrates, which may also adhere to their own ratio that could be defined by species. Further study within specimens of other species as well as earlier hominids could provide a greater understanding of vertebral-cranial connections within hominids and within all other vertebrates as well.

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REFERENCES 1. Celata, Elizabeth. Vertebral Picture. Personal Collection. France, D.L. (2004). Structures of the cranium. Lab Manual and Workbook for Physical Anthropology. Belmont: Wadsworth; 2010, 68. 2. Hamann, Carl August, & Todd T. Wingate. (1893-1938). The Hamann-Todd Osteological. Collection. Cleveland: Museum of Natural History. 3. Todd, T. Wingate. (1938). The Cleveland Museum of Natural History Hamann-Todd Human. Collection Database. Cleveland: Museum of Natural History.

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BioCRA


Original article

45

The morphometric measurements of humerus segments Kaur Jaswinder,1* Singh Zora2

Aim: The aim of the present study was to determine the lengths of humerus segments in the North population and compare these with the data available earlier for use if forensic and archeological cases. Materials and Methods: For this purpose one hundred (50 right side and 50 left side) adult dry humerus bones were taken to measure the morphometric properties of humerus segments. Six segments on the articular surface of humerus Maximum height of humerus (MHH), and the distance between the articular segment of the humeral head and the greater tuberosity (H1),Humeral head and anatomical neck(H2), proximal and distal point of the olecranon fossa(H3), the distal point of olecranon fossa and trochlea (H4), and proximal edge of olecranon fossa and proximal point of trochlea of humerus (H5)were measured with vernier caliper. Results: The distances in MHH, H1, H2, H3, H4 and H5 segments were found to be 307.0±20.9mm, 11.1±2.9mm, 31.5±3.3mm, 18.5±2.9mm, 22.6±3.0mm and 38.3±3.4mm on the right side of humerus and 303.9±18.7mm, 9.9±2.6mm, 31.6±3.1mm, 18.2±2.1mm, 21.7±2.2mm and 37.6±3.8mm on the left side of humerus respectively. No significant difference was found in the morphometric measurements between right and left side specimens. Conclusion: Our measurements on the humerus have demonstrated that the length of humerus in Northern population in our study is similar to that in Turkish population and other country population values. (J Osteol Biomat 2012; 1:45-49)

Key Words: humerus, segments, anatomy, morphometry, anthropometry, northern population

1 Associate Prof, Deptt of Anatomy Adesh Institute of Medical Sciences & Research, Bathinda 2 Professor, Deptt of Anatomy GGS Medical College, Faridkot

Correspondence to: *Jaswinder Kaur - M.S Anatomy Associate professor-Department of Anatomy, Adesh Institute of Medical Sciences & Research, Barnala Road, Bathinda Phone- 9876005164; Fax- 0164-5055255 E mail: jaswindpreet@gmail.com

INTRODUCTION The stature as a measure of biological development of both an individual and a population is commonly used in physical anthropology. The development of the stature as a very sensitive trait depends on a number of factors, such as sex, age, race, body composition, social stratum and secular trends. The proportions of its particular components also reveal great variability in relation to the overall stature within a population and between populations1. The term stature originated from the Latin statura, meaning ``height” or ``size of body”, and from the Latin verb stare meaning `` to stand”. Stature relates to the natural standing height of a living individual2. The determination of sex and estimation of stature are among the important aspect of forensic anthropology. These characteristics display population specific variation and therefore, need further attention for major populations of the world3. Estimating of stature from bones play an important role in identifying unknown bodies, parts of bodies or skeletal remains. Anthropometric techniques have been commonly used to estimate stature and bone length from the skeletal remains and unknown

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Jaswinder K. and Singh Z.

body parts by anthropologists, medical scientists and anatomists for over a hundred years4-6. Knowing the mean values of humerus segments is very important for anatomic and forensic science and helps the investigator to define the identity of a skeleton. Also, these data give evidence to indicate the characteristic features of a population for archaeological materials7-9. The estimation of bone length from incomplete long bones was firstly identified by Muller. She defined 5 segments for the humerus using the margins of articular surfaces and key points of muscle attachment9. Knowing these segment measurements which are defined, is very helpful for determining the humerus length10. Therefore, the study was made to determine the mean values and standard deviation of humerus segments in our population and compare the findings with other populations to assist in forensic and archeological cases. MATERIAL AND METHODS The bones were collected from Department of Anatomy, Adesh Institute of Medical Sciences and Research, Bathinda and Department of Anatomy, GGS Medical College, Faridkot. Different morphometric measurements from 100 (50 right, 50 left) adult humerus were taken. The lengths of the segments were measured with Vernier Caliper in mm. Six measurements were taken following the longitudinal axis of the humerus and were as follows (Figure 1.): A-F: Maximum length of the humerus, the distance between the most proximal point of the head of humerus to

Journal of Osteology and Biomaterials

Figure 1. Measurements of Humerus

the most distal point of the trochlea of humerus (MHH) Figure 2. A-B: The distance between the most proximal point of the articular segment of the humeral head to the most proximal point of the greater tuberosity( H1) A-C: The distance between the most proximal point of the head of humerus and anatomical neck of humerus (H2) D-E: The distance between the most distal point and the most proximal point along the edge of the olecranon fossa (H3) E-F: The distance between the most distal point of the olecranon fossa and trochlea of humerus (H4) D-F: The distance between along the proximal edge of the olecranon fossa and the most proximal point of the trochlea of humerus (H5)

RESULTS A total of 100adult humerus bones were included in this study. With the morphometric evaluation of the humerus, the distance from the most proximal point of the head of humerus to the most distal point of the trochlea of humerus(MHH) was found to be 307±20.9mm and 303.9±18.7mm on the right and left side of humerus respectively. The H1and H2 i.e. the distance between the most proximal point of the articular segment of the humeral head to the most proximal point of the greater tuberosity and the distance between the most proximal point of the head of humerus to the greater tuberosity were found to be 11.1±2.9 mm, 9.9±2.6 mm and 31.5±3.3 mm, 31.6±3.1 mm on right and left side of humerus respectively. The other two dimensions were from the proximal margin of olecranon fossa to distal margin of olecranon fossa and trochlea was 18.5±2.9 mm and 22.6±3.0mm on the right side and 18.2±2.1mm and 21.7±2.8mm on the left side respectively. The last measurement, between distal margin of olecranon fossa and trochlea was 38.3±3.4mm on the right side and 37.6±3.8mm on the left side of humerus. No significant difference was found between left and right sides of specimens in all parameters. The mean and standard deviation (SD) for humerus are shown in the table. DISCUSSION The humerus is the longest and largest of the upper limb and it is very important to identify the humeral length from the segmental measurements11. In forensic anthropology, a method for estimating length based on the dis-


Jaswinder K. and Singh Z.

Figure 2. Maximum length of Humerus.

tances of segments of long bones is important. In forensic and archeological studies, the mean value of total humerus length gives important evidence to indicate the characteristic features of a population 7-10. In this study the mean values of the total humerus length was identified as 307±20.9mm and 303.9±18.7mm on the right and left side respectively. When we compare our findings with other populations, the results were similar to the Spanish and Turkish population, but there were significant differences with Bulgarian and Maya populations10 . It was reported over 100 years ago that dry bones are slightly smaller than fresh ones. Proximal humeral fractures are common injuries. They occur along the physeal lines of the proximal humerus

and within its segments. Soft tissue attachments including the insertions of the rotator cuff tendons and the deltoid, pectoralis major, latissimus dorsi and teres major muscles can cause displacement of the various parts in proximal humeral fractures and likewise isolated displaced fractures of the greater tuberosity. In anatomic studies it was reported that the highest point on the articular segment of the humeral head is found 6-8mm above from the most proximal point of the greater tuberosity12-13. This relationship is important because the relative length of the greater tuberosity determines the amount of subacromial clearance as the arm is elevated. Moreover in clinical assessment this point is important for the treatment of isolated greater tuberosity fractures. In our study we found this distance on the Left humerus to be 9.9±2.6mm and on the right humerus 11.1±2.9 mm .Our mean values are similar to other anatomic studies. In a study from Guatemala with forensic Maya samples, the distance from the proximal point on the articular surface of the head of humerus to Measurements MHH H1 H2 H3 H4 H5

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the distal point of anatomical neck was32.8±2.7mm. In this study this measurement was 31.5±3.3mm and 31.6±3.1mm on the right and left side respectively. Our study is similar to this study. Olecranon fractures occur in 10% of all upper extremity lesions. The lesions might be the result of indirect or direct trauma, especially forced hyperextension of the elbow joint14. In an archeological study the distance between the proximal and distal margin of olecranon fossa was identified as 20.2±1.9mm for females and for males as 20.3± 1.3mm whereas the same distance in our study was found to be 18.5±2.9 and 18.2±2.1 mm on the right and on the left humerus respectively15. Moreover in another study the distance between the distal margin of the olecranon fossa & trochlea was identified on the right humerus as 14.2±1.8mm for males whereas in our study the same measurements was 22.6±3.0mm and 21.7±2.8mm on the right & left side respectively9. In the final measurement, the distance from the proximal margin of the olecranon fossa to the distal end of tro-

Right/Left

Mean±Standard deviation (mm)

Right Left Right Left Right Left Right Left Right Left Right Left

307±20.8 303.9±18.7 11.1±2.9 9.9±2.6 31.5±3.3 31.6±3.1 18.5±2.9 18.2±2.1 22.6±3.0 21.7±2.8 38.3±3.4 37.6±3.8

Table 1. Morphometric Measurement of the Humerus n=50(right), 50(left). From these measurements mean and standard deviation were calculated.

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Jaswinder K. and Singh Z.

chlea was found to be38.3Âą3.4 mm on the right side and 37.6Âą3.8mm on the left side. The distal humerus has a unique and special anatomy and it freely articulates with the radius and ulna. Complex distal humerus fractures provide reconstructive problems and complications such as damage to the nerves and blood vessels. Therefore these fractures are difficult for orthopedic surgeons to treat. Various implants are available for the diverse fracture patterns observed in the distal humerus and these plates are contoured specifically for the anatomy of this region. Several companies have developed anatomically based precontoured condylar plate systems that can assist with fracuture reduction 16.

Journal of Osteology and Biomaterials

CONCLUSIONS The knowledge of morphometric values of humerus segments is important in forensic, anatomic and archeological cases in order to identify unknown bodies and statures. It is also helpful for the clinicians in the treatment of proximal and distal humerus fractures. Therefore our study supplies the mean values of the different morphometric measurements from the humerus. As a result, these measurements may help to indicate the characteristic morphological features of humerus segments in our population and also help the orthopedic surgeons to place the various implants in the reconstruction of humerus fractures.


Jaswinder K. and Singh Z.

REFERENCES 1. Kozak J. Stature reconstruction from long bones. The estimation of the usefulness of some selected methods for skeletal populations from Poland. Variability and evaluation ,1996;Vol.5:83-94 2. Baines KN, Edmond S and Eisma R. Forensic anthropology: Introduction and overview. 2000 to 2010 edited by Eilidh ferguson Taylor & francis: 95-96

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influencing outcome. Injury Int J care Injured 2004;34:1149-1157 15. Churchill SE,Smith FH. A modern human humerus from the early Aurignacian of Vogelherdhole ( Stetten , Germany) Am J Phys Anthropol 2000;112:251-273 16. Jupiter JB, Mehne DK. Fracture of distal humerus. Orthopedics 1992;15:825-833

3. Iscan MY. Forensic anthropology of sex and body size. Forensic international journal 2005;Vol.147, issue2,:107-112 4. Beddoe J. On the stature of the older races of England, as estimated from the long bones. JR Anthropol Inst 18871888;17:202-207 5. Ozaslan A, Iscan MY, Ozaslan l et al. Estimation of stature from body parts. Forensic Sci Int 2003; 1:1-6 6. Pearson K. Mathematical contribution to the theory of evaluation.On the reconstruction of the stature of prehistoric races. Philos Trans R Soc Lond 1899;192:169-244 7. Koshy S, Vettivel S and Selvaral KG. Estimation of length of calcanuem and talus from their body markers. Forensic Sci INt 2002;129:200-204 8. Mall G, Hubig M and Buttner. A sex determination and estimation of stature from the long bones of the arm. Forensic Sci Int 2001; 117:23-30 9. Wright LE and Vasquez MA. Estimation the length of incomplete long bones. Forensic standards from Guatemala. Am J Phys Anthropol 2003;120:233-251 10. Munoz JI, Iglesias ML and Penaranda JMS. Stature estimation from radiographically determined long bone length in a Spanish population sample. Forensic Sci Int 2001;46:363-366 11. William PL, Warwick R, Dyson M, Bannister LH.The humerus. In: Gray`s anatomy, 37th edn. Churchill Liningstone 1989; 406 12. Green A,lzzi J. Isolated fractures of the greater tuberosity of the proximal humerus. J Shoulder Elbow Surg 2003;12:641-649 13. Lannotti JP,Gabriel JP and Schneck SL . Hundred and forty shoulders. J Bone joint Surg Am 1992;74:491-500 14. Rommens PM,Kuchle R,Schneider RU etal.Olecranon fractures in adults: factors

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JOB - Vol. 3 N. 1 - 2012