Clinical Implications of Growth & Indicators of Growth INDIAN DENTAL ACADEMY
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Growth:- the detailed analysis of human growth was first presented by Quetlet in 1842.
Definition:- It is physiochemical process of living matter by which an organism becomes larger.
J.S.Huxley defines growth as self multiplication of a living substance. Krogman defines physical growth as increase in size, change in proportion and progressive complexity.
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Types of Growth: Morphogenetic
Somatogenetic Somatogenetic:-
It is the growth of the body, controlled by target glands, thyroids and gonads.
Morphogenetic:It is the cellular and tissue differentiation in early embryo which leads to establishment of form & structure of various organs & parts of the body. This is controlled by anterior lobe of the pituitary. www.indiandentalacademy.com
*Factors influencing growth:1) Hereditary 2) Environmental 3) Sexual 4) Nutritional www.indiandentalacademy.com
In a newborn 100% of the body weight is divided into a) b)
35% - which is comprised of organs & blood 65% - which is comprised of bone, Muscle & fat
In a full-grown adult 100% body weight is divided into a) b) c) d)
20% - bone 40% - muscle 20% - fat 20% - organs & blood www.indiandentalacademy.com
*Rhythm of Growth :According to Hooton – it is not a steady & uniform process of accretion in which all the body parts enlarge at the same rate & the increment of 1 year is equal to that of preceding / succeeding years. Growth takes place by fits & starts. www.indiandentalacademy.com
*Parts of the Growth Rhythm are:1) 1st Rapid rhythm :- starts from Birth & continues till the 5th / 6th year for both males & females. Increased rapidity is found in the 1 st two years. (This stage is followed by) www.indiandentalacademy.com
2) Period of Slower Increase:For boys it’s from the 10th to the 12th For girls it’s up to the 10th year. ( followed by)
year
3) Period of Accelerated growth :This period is termed as Adolescence. For males it is between 16th to the 18th year, For females it gets completed between 14th to the 16th year of life www.indiandentalacademy.com ( followed by)
4) Final Period of Slow growth :For males it terminates about 25 th year, For females it ends between 18 – 20 years
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* Increments of growth :In infancy – absolute growth is small but percentage growth is proportionately large when compared to later years. Growth in infancy is very rapid than in any other period of postnatal life. In adults – variability of growth is much higher due to different times of onset of growth acceleration. www.indiandentalacademy.com
* Rate of growth :It is most rapid at the beginning of cellular differentiation , increases until birth & decreases thereafter because of continuation of cellular differentiation.
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* Spurts of growth:Occurs due to differential activity of growth centers wherein certain growth centers may be active at one time than the others. This rapid increase in the growth rate occurs a) Just before birth b) Just before & at the beginning of Puberty www.indiandentalacademy.com
* Patterns of Growth :According to Brodie it’s not only the shape & size of the body parts but also the rate, time & the manner in which these are attained.
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Cephalo Caudal gradient of growth :In fetal life – at about 3rd month of Intra uterine life, head occupies almost 50% of the total body length. At this stage the cranium is large relative to the face & represents more than half the total head. In contrast, the limbs are still rudimentary & the trunk is underdeveloped www.indiandentalacademy.com
By birth :- the trunk & the limbs are grown faster than the head & the face so that the portion of entire body devoted to the head has decreased to about 30%. Overall growth pattern follows this course, with a progressive reduction of the relative size of the head to about 12% of the adult. At birth the legs represent about one third of the total body length while in the adults they represent about half. These changes are termed as “ Cephalocaudal gradient of growth “ meaning that there’s an axis of increased growth extending from the head towards the feet. www.indiandentalacademy.com
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Scammons Growth curve:Growth curve showing 4 major tissue systems of the body. a) Growth of the Neural tissues is nearly complete by 6/7 yrs of age. b) General body tissues including muscle, bone & viscera show an “s� shaped curve with a definite slowing of the growth rate during childhood & an acceleration at puberty. c) Lymphoid tissue proliferation occurs far beyond the adult amount in late childhood & then undergo an involution at the same time that growth of the genital tissues accelerates rapidly. www.indiandentalacademy.com
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* Skeletal Maturation :Defined as the process of becoming fully developed. Skeletal maturation begins with puberty & is complete when the epiphyses are closed. The intermediate phase between puberty & closure of epiphyses is termed as Adolescencewherein most of individual’s growth & development occurs. www.indiandentalacademy.com
* Variation in rate of skeletal maturation:-
a) children who mature early follow a different course of growth than those who mature late. b) Rapid maturation of the skeleton is usually associated with lack of increase in height attained. c) Early maturing children show greater gain in skeletal age in relation to chronologic age. Late maturing children show retardation in skeletal maturation related to chronological age. www.indiandentalacademy.com
d) Bambha & Van Natta state that children who mature early & who have advanced skeletal age also show early adolescent dentofacial growth. e) Rate of skeletal maturation & degree of physical growth to be attained by each individual are basically controlled by Heredity. f) Variations in the rate of skeletal maturation does exist between boys & girls wherein girls tend to mature faster than the boys. www.indiandentalacademy.com
* Influences of disease on growth:-
a)Di sease & functional disturbances in
infancy & early childhood can interfere with growth & development. These interferences may/ may not be successfully overcome during later childhood & adolescence. b) Disease affects the relative rate of growth either in a transitory / in a permanent manner depending on the www.indiandentalacademy.com
* Factors causing disturbance of growth :1) Genetic/ Constitutional:Retardation of growth may be the result of organizer hormone deficiency which interferes with tissue differentiation during embryonic stage. These effects are manifested later in intra-uterine life/ after birth. Genetic Influence is strong on Height & weight which is related to Nutrition. Eg of genetic disorders are a) Achondroplasia b) Mongolism c) Primordial dwarfism d) Hereditary craniofacial dysostosis e) Ovarian agenesis www.indiandentalacademy.com
2) Nutritional deficiency :Growth requires properly utilized adequate diet. Nutritional deficiencies result from defects in organs responsible for absorption, transportation, assimilation / excretion of essential food substances & their metabolites. 3) Metabolic disturbances:Disturbed calcium – phosphorous metabolism interferes with growth as in childhood diabetes & Hypocalcaemia. Metabolic disorders occurring during embryonic period & in childhood - alter the growth & development in 2 ways. a) by modifying the differentiation of tissues b) by changing the growth & development at a later stage and thereby result in marked deviation in the somatic pattern. www.indiandentalacademy.com
4) Chronic diseases:Celiac diseases, Hepatic insufficiency, allergy, rickets, chronic renal diseases, cystic fibrosis of pancreas etc. 5) Blood dyscrasias:Chondrodystrophy, dysostosis & osteogenesis imperfecta. 6) Circulatory diseases :- Pulmonary deficiency, cardiac malformations. www.indiandentalacademy.com
7) Endocrinal disturbances:a) Hypothyrodism :- characterized by 1) Stunting of growth 2) Infantile skeletal proportions 3) Delayed & defective tooth development 4) Epiphyseal dysgenesis Hypothyroidism occurs congenitally & in childhood. When occurring congenitally – it affects the bones which are both cartilagenous & intra-membranous in origin. www.indiandentalacademy.com
When it occurs in childhood its divided into 1) Cretinism:- Hypothyroidism occurs at 6yrs/ below. Here the patient has a large head, face is coarse, presents a dull & infantile facial expression & the nasal area appears shrunken. Dental changes seen are – delay of ossification of the tooth buds due to delay in Endochondral ossification. www.indiandentalacademy.com
Hypothyroidism after 6yrs & before puberty:- the characteristic features are a) retardation in normal rate of calcium deposition in bones & in tooth buds. b) Delayed carpal & epiphyseal calcification c) Disharmonies in the eruption of teeth. d) Incomplete unfolding of the nasal area & inadequate development of the maxilla. e) Prolonged retention of the deciduous teeth. f) Delayed eruption of the permanent teeth g) Abnormal dental calcification & root resorption. www.indiandentalacademy.com
B) Hyperthyroidism – produces an increase in rate of maturation. Characterized by a) Premature eruption & resorption of roots of deciduous teeth. b) Early eruption of permanent teeth c) Fragility of the bones d) Increased salivary secretion e) Acceleration of skeletal ossification f) Osteoporosis may be present which contra indicates orthodontic treatment. www.indiandentalacademy.com
Shirazi & Dehpour in J.Clin Pediatr Dent. ( spring 1999 ) performed a study to evaluate the effect of thyroid hormone on orthodontic tooth movement in rats. The study was performed on 50 rats which were divided into 5 groups namely a normal group with no intervention, a control group in which appliances were placed & 10ml/kg i.p/day normal saline was injected, & 3 thyroxin groups in which appliances were placed & 5,10,20 microgram/kg i.p /day L-thyroxin were administered, respectively. A fixed orthodontic appliance consisting of a 5 mm closed-coil spring was ligated between the maxillary www.indiandentalacademy.com
The results showed that administration of 20/microgram/kg i.p/day L-thyroxin significantly increased the amount of orthodontic tooth movement. The extent of root resorption as seen from scanning electron micrographs decreased with thyroxin administration. www.indiandentalacademy.com
B) Growth Hormone:Hypersecretion:- termed as gigantism in childhood & acromegaly in adulthood. If this condition occurs – growth may extend up to 25/ 30 yrs. Clinical features are, 1) enlargement of the supra orbital ridges & changes in the jaws especially the mandible. 2) Increase in the mandibular prognathism 3) Enlargement & spacing between the www.indiandentalacademy.com teeth of the maxillary arch.
4) Both the jaws show increased labial inclination of the incisors. 5) Head appears coarse, the ears , nose & the lips are thick, soft tissues are thickened. 6) Mandible:- greater increase in the length of the ramus of the mandible as a result of the type of ossification of the condyle. There’s an over apposition of the bone at alveolar crest which increases the height of the mandibular body leading to marked enlargement of entire mandible. 7) Spacing occurs in the mandibular dentition. In Hyposecretion:- there’s retardation of tooth development & eruption. www.indiandentalacademy.com
Kahlili , Forsberg et al (Acta Odontol Scand. 2002 Aug) performed a study to investigate whether craniofacial morphology differs between obese adolescents and normal weight adolescents. Lateral cephalograms from 39 adolescents with obesity, aged 14-16 years, were analysed and compared with lateral cephalograms from an equal number of sex- and agedmatched controls. The authors observed that compared to the controls, the subjects in the obesity group showed increased mandibular length, prognathic jaws and a reduced upper anterior face height. Despite low GH levels, obese children have normal levels of insulin-like growth factor (IGF-1). Therefore they conclude that craniofacial growth may be more dependent on free circulating IGF-1 than on the locally produced portion. www.indiandentalacademy.com
C) Adrenal Gland:1) In Adrenogenital syndrome – the teeth show acceleration of development & eruption. 2) Tumours of the Adrenals at the time of tooth development may produce premature eruption of permanent teeth. 3) Adrenocortic Hyperfunction brings about a reduction in protein body mass, including the bony matrix into which calcium is deposited when bone is formed thereby interfering with bone formation. www.indiandentalacademy.com
Precocious puberty:Sexual precocity may be due to disturbances in the brain, pituitary, adrenals/ gonads. The features are, growth is accelerated at first but advanced epiphyseal closure finally arrests growth. This precocious sexual development has been found to depend in one instance on a sex linked autosomal gene.The traits were transmitted by affected males, carrier females & genotypically affected but phenotypically normal males to about half their offspring. Precocious sexual development due to constitutional causes shows accelerated height & weight. Adolescent symptoms occur at much earlier age. Bone age is advanced. www.indiandentalacademy.com
* Effects of diseases on growth:1) Differentiation is inhibited – which is either A) Complete – as in Hypophyseal disorders, Achondroplasia (or) B) Temporary – as in Rickets, Celiac disease etc. Here the affected child may gradually recover. 2) local manifestations of growth disorders :a) Infantile paralysis – may impede growth of a part but not the general development b) Chronic osteochondritis www.indiandentalacademy.com
*Clinical appraisal of growth:1) Dental age & it’s relationship to growth:Chronologic age is related to dentition. Mean number of erupted permanent teeth at the respective age is higher in girls than in boys. 2) BMR:- it is the rate expressed in calories of body heat produced per square meter per hour. Wetzel states that there’s a direct relationship between BMR & Growth. www.indiandentalacademy.com
3) Calcium retention & bone growth:Stearns has indicated that retention of calcium can be used as an index for evaluating the rate of bone growth. All retained skeletal phosphorous is held in combination with calcium & calcium : Phosphorous ratio of bone is approximately 2:1. Therefore with amount of calcium retention, it’s possible to predict whether bone is being formed slowly / rapidly. www.indiandentalacademy.com
* Methods of studying Physical growth :There are 2 basic approaches to study physical growth , they are 1) Measurement approach – wherein measurements are made on animals / humans 2) Experimental approach www.indiandentalacademy.com
The measurement approach is divided into 3 types as follows,
a) Craniometry :Based on measurements of skulls found among human skeletal remains. Initially this method was used to study Neanderthal & Cro-Magnon people’s skulls which were found in the European Caves in the 18th & 19th century. This study gives an idea about the pattern of growth by comparing one skull with another. Advantage:- Precise measurements can be made on dry skulls Disadvantage:- All the growth data accumulated is only cross sectional wherein the skull of an individual can be measured at one time only. www.indiandentalacademy.com
b) Anthropometry:Defined as skeletal dimensions measured on living individuals. Various landmarks measured on dry skulls are measured in living individuals by using soft tissue points overlying these bony landmarks. Adv:- Measurements can be made on dry skulls as well as in living individuals. Disadv:- results would be different between the measurements on dry skull & on soft tissues overlying the bony landmarks. Even though there’s variation due to soft tissue covering, the measurements can be made repeatedly on the same person over a period of time- making it a longitudinal study. www.indiandentalacademy.com
c) Cephalometry:This procedure combines the advantage of Craniometry & anthropometry. This technique depends on precisely orienting the head before making a radiograph with equally precise control of magnification. Adv:- 1) allows direct measurement of bony skeletal dimensions. 2) Measurements can be recorded in the same individual over the time. Disadv:- it produces a 2 dimensional representation of a 3D structure & with even precise head positioning – not all measurements are possible. www.indiandentalacademy.com
II) Experimental approach:1) Vital staining:- dyes staining the mineralized tissues are injected into an animal to know more about skeletal growth. These dyes remain in the bone & teeth & can be detected later after sacrifice of the animal. The dye used is Alizarin. This reacts with calcium at sites where bone calcification is occurring. As these sites are of active skeletal growth, the dye marks the location where the active growth occurs. Areas where bone is being removed can also be identified as in those areas – the vital stain is removed. www.indiandentalacademy.com
Disadv:- not possible to be employed in human studies. Therefore with the advent of Radioactive tracers – vital staining could be performed in humans. The materials used is Gamma emitting isotope – Technicium 99, which can be used to detect areas of rapid bone growth in humans. The location is detected by weak radioactivity given off at the site where the material is incorporated. But these images are more useful for diagnosing localized growth problems. www.indiandentalacademy.com
2)Autoradiography:- a film emulsion is placed over a thin section of tissue containing the radioactive isotope & then is exposed in the dark by radiation. After the film is developed the location of the radiation indicating the area of growth occurrence can be observed by looking at the tissue section through the film. 3) Molecular genetics:a) Transforming growth factor beta genes are important for regulating cell growth & organ development. b) Bone morphogenic protein – directly affect www.indiandentalacademy.com the skeletal development, they are helpful in
4) Implant radiography:Inert metal pins are placed in bones anywhere in the skeleton including face & jaws. These pins are well tolerated by the skeleton & become permanently incorporated into the bone without causing any problems. Prof. Arne Bjork – Royal Dental College, Denmark, performed growth study by placing metallic implants in the jaws , wherein with the help of cephalometric radiographs preoperative & postoperative, the growth could be measured. Ie:-the consecutive radiographs taken at the time of implant placement & over a period of time was superimposed on the implant & with which the following werewww.indiandentalacademy.com analyzed,
a) position of 1 bone relative to another b) changes in external contours of idividual bones. Adv:- Precise evaluation of dentofacial growth in humans can be performed by this method. www.indiandentalacademy.com
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* Occurrence of Growth:a) at the skeletal level :- occurs by 1) Hypertrophy :- defined as increase in the size of the individual cell Or 2) Hyperplasia :- increase in the no. of cells Or 3) Secretion of extra cellular material:- thereby the size of the body part increases independent of the no. / size of the cell. www.indiandentalacademy.com
b) at the soft tissue level :- occurs by Hypertrophy & Hyperplasia which result in growth occurring at all points within the tissue which is termed as Interstitial growth.
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* Assessment of Skeletal Age
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Bone age presents an indication of physical development & maturation of the skeleton. Standards obtained by means of roentgenograms are employed to determine the order, rate, time of appearance and progress of ossification of various centers of skeletal ossification. Certain bones like Carpal’s, Femur, elbow joint, shoulder joint & the skull can be used for this purpose. The hand, the wrist & the distal Epiphyses of the Radius & the Ulna present a large no. of secondary centers of ossification which can be reproduced on a Roentgenogram to determine the state of skeletal maturation. www.indiandentalacademy.com
Pyle & coworkers advice that assessment of skeletal age must take into consideration the time of onset of calcification. This onset of calcification for some children may begin later than in others and may extend over a longer period. Familial pattern of ossification should be ascertained. www.indiandentalacademy.com
Carpal’s in orthodontic diagnosis a) The carpal bones, epiphyses, phalanges& meta carpals provide a clue to the bone growth in the body as a whole. b) Ossification occurs in the period after birth & before maturity Carpal bones:1st named by Lyser in 1683. they are short, spongy bones enclosed in a thin layer of compact bone. www.indiandentalacademy.com
Carpal bones are of 2 rows, a) proximal row:- made up of 1 Navicular – bone with a concave surface with some resemblance to a boat. 2 Lunate- distal surface shows deep concavity, lateral surface like crescent moon. 3 Triquetral – Pyramidal, triangular wedge shaped. 4 Pisiform – smallest of the group, round spheroidal, pea shaped.
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Triquetral
Lunate Pisiform
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b) Distal row made up of :1 Greater Multangular- 4 sided bone with none of the sides parallel. 2 Lesser multangular – somewhat wedge shaped 3 Capitate- largest bone with rounded extremity/ head on the proximal surface. 4 Hamate- hooked curved on the inner side. www.indiandentalacademy.com
Capitate
Hamate
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Each of the carpal bones except the pisiform has 6 surfaces which are ( proximal, Distal, Volar, Dorsal, Lateral, Medial) Carpals in the assessment of skeletal maturation:Ranke in 1896 was the 1st to study skeletal developmental progress by means of wrist roentgenograms. Rotch in 1910 recognised that weight, height & tooth eruption were at best but rough estimates of physical maturity in terms of chronological age. Bayley in 1943 found a correlation between maturation of the hand & the knee as seen on the roentgenogram up to the age 13yrs. www.indiandentalacademy.com
Garn & Rohmann conclude that hand wrist ossification is useful in detecting growth abnormalities, but not a precise method of measuring developmental progress in normal individuals. The approximate skeletal age of the child may be estimated by the no. of carpal bones showing centers of ossification and by degree of ossification attained by the respective carpals. However there’s a wide range of variation within the normal limits of the carpal ossification, as well as a difference between the sexes. www.indiandentalacademy.com
An infant at 1yr of age may show ossification of 2 & occasionally 3 carpal bones. All carpal bones should show ossification between 67yrs of age in boys & between 4-5 yrs in girls. But every hand may show some minor variations from the usual developmental patterns and the hands of the same child may vary. Disadvantage :- are to establish a maturation rate one hand wrist film is not sufficient and gives only little information. In addition the average maturation rate of the girls is significantly greater than that of boys. www.indiandentalacademy.com
Fishman system:- (1982 AO) This system employ’s only four stages of bone maturation – found at six anatomical sites located on the thumb, third finger , fifth finger and radius. On these six sites eleven discrete adolescent skeletal maturation indicators are present. www.indiandentalacademy.com
The four ossification stages are:Widening of epiphyses on selected phalanges . Ossification of adductor sesamoid of the thumb Capping of selected epiphysis over the diaphyses Fusion of selected epiphysis & diaphysis www.indiandentalacademy.com
I) Epiphyseal widening on selected phalanges present on
1. Proximal phalanx Of 3rd finger 2. Middle phalanx 3. Middle phalanx – of fifth finger
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II) Ossification of Adductor Sesamoid of thumb ( SMI no. 4)
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III Capping of epiphysis a) Distal phalanx - 5 Middle phalanx - 6
Of 3rd finger
b) Middle phalanx – of fifth finger - 7
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IV) Epiphysis and Diaphyses fusion seen in a. Distal phalanx - no. 8 Proximal phalanx -no. 9 Middle phalanx -no.10
Of third finger
b.Radius no.11
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III Hagg & Taranger in 1982 (AJO) Performed a study in Swedish population to find out whether dental development / skeletal development could be considered as the diagnostic criteria for assessing the pubertal growth spurt in children so as to time the orthodontic treatment modalities accordingly. In order to obtain maturation indicators of shorter duration, they included 2 new stages in the skeletal maturity indicators One stage in the middle phalanx of the 3rd finger denoted as MP3-FG One stage in the distal end of radius denoted as R-IJ www.indiandentalacademy.com
The ulnar sesamoid (S) of the metacarpophalangeal joint of the first finger before and after ossifying. The distal phalanx of the third finger (DP3) before and after Stage l: fusion of the epiphysis and metaphysis is completed. The middle phalanx of the third finger (MP3): Stage F— the epiphysis is as wide as the metaphysis. Stage FG— the epiphysis is as wide as the metaphysis and there is distinct medial and/or lateral border of the epiphysis forming a line of demarcation at right angles to the distal border. Stage G— the sides of the epiphysis have thickened and also cap its metaphysis, forming a sharp edge distally at one or both sides. Stage H— fusion of the epiphysis and metaphysis has begun. Stage I— fusion of the epiphysis and metaphysis is completed. The distal epiphysis of the radius: Stage I— fusion of the epiphysis and metaphysis has begun. Stage IJ— fusion is almost completed but there is still a small gap at one or both margins. Stage J— fusion of the epiphysis and metaphysis is completed. www.indiandentalacademy.com
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Dental development was assessed by dental emergence stages(DES) and pubertal development was assessed from 10 to 18 years by determining the occurrence of menarche in girls and voice changes in boys. They conclude in their study that a) There was a 2 year sex difference in age at beginning , peak and end of pubertal growth spurt b) Dental development assessed by means of dental emergence stages was not useful as an indicator of pubertal growth spurt www.indiandentalacademy.com
c) Dental development in relation to pubertal growth spurt was more advanced in boys than in girls. d) The peak high velocity (PHV) & the end but not the beginning of pubertal growth spurt could be determined by means of indicators taken from the skeletal development of the hand & wrist. www.indiandentalacademy.com
Sesamoid S was usually period of the pubertal growth spurt (ONSET-PHV). Middle third phalanx MP3-F was attained before ONSET. MP3-FG was attained 1 year before or at PHV . MP3-G was attained at or 1 year after PHV MP3-H was attained after PHV but before END MP3-I was attained before or at END Distal third phalanx DP3-I was attained during the deceleration period of the pubertal growth spurt (PHV-END) by all subjects. Radius R-I was attained 1 year before or at END R-IJ and R-J were not attained before END by any subject.
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IV) Alicia M.Sierra (AO 1987 Jul) Performed a study to evaluate the correlation between stages of those individual ossific centers that exhibit the least variability in their onset of ossification & the calcification of the upper & lower cuspids, bicuspids & 2nd molars in the permanent dentition. The teeth were selected because their period of formation corresponds with age range of the subjects in this study. www.indiandentalacademy.com
Hand wrist films were based on maturity indicators developed by Greulich & Pyle (1959). & these were compared to the Nolla’s Dental classification of stages of tooth calcification. The results obtained in this study ( ossific center method) were compared with Todd Inspectional method (TIM) performed in the same study. This was done to compare the efficacy of the methods. www.indiandentalacademy.com
8 ossific centers exhibiting least variability in timing of the onset of ossification were assessed. The correlations found between calcification of the teeth & skeletal age assessment by OCM method were found to be high. Strongest correlation was between ossific centers & lower cuspids followed by upper 1st bicuspid. 2nd bicuspid seemed least reliable when correlated to ossific centers. The author concludes that correlation of dental age with OCM & TIM are similar but OCM provides the same information from a quicker & easier assessment of skeletal age. www.indiandentalacademy.com
Tooth mineralisation as an indicator of pubertal growth spurt Seymour Chertkow (1980 AJO Jan) performed a study to evaluate whether tooth could be used as a maturational indicator to predict growth. He found that the Mandibular canine calcification stage G, ie stage of root formation prior to closure of the apices, corresponded with the maturational stage characterised by, 1) Adductor sesamoid ossification, 2) Ossification of the Hook of the Hamate, 3) Capping of the Epiphyses of the Middle Phalanx of the 3rd finger, These stages characterize the onset of Pubertal Growth spurt. www.indiandentalacademy.com
V) Shigemi Goto & Takamasa Kondo ( AJO 1996 Nov) performed a study in Japanese population to find out the rate of mandibular growth when associated with ossification of the epiphyses of the distal phalanx of the 1 st digit. Recent studies have shown that epiphyseal ossification of the distal phalanx of the 1 st digit occurs after the pubertal growth spurt. As this maturation event is closely ass. With a declining growth rate of mandibular condyles in particular in girls, it may be an indication for when to initiate orthodontic treatment in subjects with mild – moderate skeletal Cl III malocclusion. www.indiandentalacademy.com
Ossification event of distal phalanx of first digit. Stage E0: No epiphysis; Stage E1: Narrower epiphysis than diaphysis; Stage E2: As wide epiphysis as diaphysis; Stage E3: Wider epiphysis than diaphysis; Stage E4: Wider epiphysis than diaphysis with threequarters of epiphysis union; Stage E5: Complete epiphyseal union www.indiandentalacademy.com
The author’s state that ossification begins at an early age & continues over a period of several yrs. Complete epiphyseal union in over half of the subjects took place between 12-13 yrs in girls & after 14 yrs in boys.
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Clinical Implications The author’s conclude that determination of the stage of skeletal maturation of the 1st digit of the distal phalanx may provide a quick & useful clinical method for assessing residual growth potential in patients with mild – moderate Cl III malocclusion. However caution should be exercised as mandibular growth may still continue after the closure of the distal Phalanx of the 1st digit, especially in more severe cl III malocclusions that are due to mandibular prognathism. www.indiandentalacademy.com
Rajagopal and kansal(2002) Hagg and taranger were based on five stages of MP3 growth based primarily epiphyseal change This method used changes observed in the metaphyseal region. They provided an additional bone stage between MP3-H (deceleration of the curve of the pubertal growth spurt) and MP3-I (end of the pubertal growth spurt), which they called the MP3-HI stage, resulting in a total of six stages of MP3 growth. www.indiandentalacademy.com
MP3-HI stage: Maturation of the curve of pubertal growth spurt Features of this “new� stage observed in this study: 1. Superior surface of epiphysis shows smooth concavity. 2. Metaphysis shows smooth, convex surface, almost fitting into reciprocal concavity of epiphysis. 3. No undulation is present in metaphysis. 4. Radiolucent gap between epiphysis and metaphysis is insignificant.
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MP3-I stage: End of pubertal growth spurt 1. Fusion of epiphysis and metaphysis complete Additional features observed in this study 2. No radiolucent gap exists between metaphysis and epiphysis 3. Dense, radiopaque epiphyseal line forms integral part of proximal portion of middle phalanx
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Cervical vertebra
The first seven vertebrae in the spinal column constitute the cervical spine. The first two, the atlas and the axis, are quite unique, the third through the seventh have great similarity Vertebral growth takes place from the cartilagenous layer on the superior and inferior surfaces of each vertebrae.Secondary ossification nuclei on the tips of the bifid spinous processes and transverse processes appear during puberty.Secondary ossification nuclei unite with the spinous processes when vertebral growth is complete. After completion of endochondral ossification, growth of the vertebral body takes place by periosteal apposition. It appears to take place only at the front and sides www.indiandentalacademy.com
II) Cervical Vertebral Maturation Method.:History:Todd & Pyle , Lanier & taylor measured dimensional growth modifications in the cervical vertebrae on the lateral radiographs. Lamparski created separate standards of cervical vertebral maturation for female & male subjects as related to both chronological age & skeletal maturation observed in the hand & wrist radiograph. The method analyzed size & shape changes in the bodies of 5 cervical vertebrae. Â www.indiandentalacademy.com
Hassel & Farman (1995 AJO) Developed a method of assessing skeletal maturation of the cervical vertebra assessed from lateral cephalometric head film & combined it along with the skeletal maturity indicator of hand & wrist developed by Fishman. www.indiandentalacademy.com
Category 1 was called INITIATION. This corresponded to a combination of SMI 1 and 2. At this stage, adolescent growth was just beginning and 80% to 100% of adolescent growth was expected. Inferior borders of C2, C3, and C4 were flat at this stage. The vertebrae were wedge shaped, and the superior vertebral borders were tapered from posterior to anterior
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Category 2 was called ACCELERATION. This corresponded to a combination of SMI 3 and 4. Growth acceleration was beginning at this stage, with 65% to 85% of adolescent growth expected. Concavities were developing in the inferior borders of C2 and C3. The inferior border of C4 was flat. The bodies of C3 and C4 were nearly rectangular in shape
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Category 3 was called TRANSITION. This corresponded to a combination of SMI 5 and 6. Adolescent growth was still accelerating at this stage toward peak height velocity, with 25% to 65% of adolescent growth expected. Distinct concavities were seen in the inferior borders of C2 and C3. A concavity was beginning to develop in the inferior border of C4. The bodies of C3 and C4 were rectangular in shape
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Category 4 was called DECELERATION. This corresponded to a combination of SMI 7 and 8. Adolescent growth began to decelerate dramatically at this stage, with 10% to 25% of adolescent growth expected. Distinct concavities were seen in the inferior borders of C2, C3, and C4. The vertebral bodies of C3 and C4 were becoming more square in shape
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Category 5 was called MATURATION. This corresponded to a combination of SMI 9 and 10. Final maturation of the vertebrae took place during this stage, with 5% to 10% of adolescent growth expected. More accentuated concavities were seen in the inferior borders of C2, C3, and C4. The bodies of C3 and C4 were nearly square to square in shape.
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Category 6 was called COMPLETION. This corresponded to SMI 11. Growth was considered to be complete at this stage. Little or no adolescent growth was expected. Deep concavities were seen in the inferior borders of C2, C3, and C4. The bodies of C3 and C4 were square or were greater in vertical dimension than in horizontal dimension.
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Stages 1 through 3 were generally observed prior to peak velocity for all the mandibular dimensions, with stages 2 and 3 occurring in the year immediately preceeding peak. Stages 2 and 3 were observed in the year immediately preceeding the maximum increment for corpus length stage 3. Stage 4 also occurred prior to peak in three subjects, and in the other ten subjects stages 4 through 6 occurred after peak velocity.
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Advantage:The orthodontist could obtain additional information about the growth potential in the adolescent patient by observing the anatomical changes of the cervical vertebrae, thereby formulation of a treatment could be made. Apart from this any anomalies in the Cervical spine of children & adolescents like fractures, infections, polyarthritis, ankylosis & ankylosing spondylitis etc can be identified. www.indiandentalacademy.com
Franchi, Bacetti & McNamara (2002 AJO) Presented an improved version of the CVM method to test its validity for the appraisal of mandibular skeletal maturity in the individual patient. The morphology of the bodies of the second (odontoid process, C2), third (C3), and fourth (C4) cervical vertebrae were analyzed in the six consecutive observations (T1 through T6). The analysis consisted of both visual and cephalometric appraisals of morphological characteristics of the cervical vertebrae. www.indiandentalacademy.com
On the lateral cephalograms, the following points for the description of the morphologic characteristics of the cervical vertebral bodies were traced and digitized. C2p, C2m, C2a: the most posterior, the deepest and the most anterior points on the lower border of the body of C2. C3up, C3ua: the most superior points of the posterior and anterior borders of the body of C3. C3lp, C3m, C3la: the most posterior, the deepest and the most anterior points on the lower border of the body of C3. C4up, C4ua: the most superior points of the posterior and anterior borders of the body of C4. C4lp, C4m, C4la: the most posterior, the deepest and the most anterior points on the lower border of the body www.indiandentalacademy.com
With the aid of these landmarks, the following measurements were performed:
C2Conc: a measure of the concavity depth at the lower border of C2 (distance from the line connecting C2p and C2a to the deepest point on the lower border of the vertebra, C2m). C3Conc: a measure of the concavity depth at the lower border of C3 (distance from the line connecting C3lp and C3la to the deepest point on the lower border of the vertebra, C3m). C4Conc: a measure of the concavity depth at the lower border of C4 (distance from the line connecting C4lp and C4la to the deepest point on the lower border of the vertebra, C4m). C3BAR: ratio between the length of the base (distance C3lp-C3la) and the anterior height (distance C3ua- C3la) of the body of C3. C3PAR: ratio between the posterior (distance C3up-C3lp) and anterior (distance C3ua-C3la) heights of the body of C3. C4BAR: ratio between the length of the base (distance C4lp-C4la) and the anterior height (distance C4ua- C4la) of the body of C4. C4PAR: ratio between the posterior (distance C4up-C4lp) and anterior (distance C4ua-C4la) heights of the body www.indiandentalacademy.com
The findings of both the inspective and cephalometric analyses revealed that no statistically significant discrimination can be made between Cvs 1 and Cvs 2 as defined in the former CVM method. two former stages (Cvs 1 and Cvs 2) merge into one single stage. This newly described Cervical Vertebral Maturation Stage is referred to as CVMS The appearance of a visible concavity at the lower border of the third cervical vertebra is the anatomic characteristic that mostly accounts for the identification of the stage immediately preceding the peak in mandibular growth (former Cvs 3, actual CVMS II)
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CVMS I: the lower borders of all the three vertebrae are flat, with the possible exception of a concavity at the lower border of C2 in almost half of the cases. The bodies of both C3 and C4 are trapezoid in shape (the superior border of the vertebral body is tapered from posterior to anterior). The peak in mandibular growth will occur not earlier than one year after this stage. CVMS II: Concavities at the lower borders of both C2 and C3 are present. The bodies of C3 and C4 may be either trapezoid or rectangular horizontal in shape. The peak in mandibular growth will occur within one year after this stage. CVMS III: Concavities at the lower borders of C2, C3, and C4 now are present. The bodies of both C3 and C4 are rectangular horizontal in shape. The peak in mandibular growth has occurred within one or two years before this stage. CVMS IV: The concavities at the lower borders of C2, C3,and C4 still are present. At least one of the bodies of C3 and C4 is squared in shape. If not squared, the body of the other cervical vertebra still is rectangular horizontal. The peak in mandibular growth has occurred not later than one year before this stage. CVMS V: The concavities at the lower borders of C2, C3,and C4 still are evident. At least one of the bodies of C3 and C4 is rectangular vertical in shape. If not rectangular vertical, the body of the other cervical vertebra is squared. The peak in mandibular growth has occurred not later than two years before this stage. www.indiandentalacademy.com
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The authors conclude that:The new CVM method is comprised of five maturational stages (CVMS I through CVMS V, instead of Cvs 1 through Cvs 6 in the former CVM method), with the peak in mandibular growth occurring between CVMS II and CVMS III.
The pubertal peak has not been reached without the attainment of both CVMS I and CVMS II.
The new method is particularly useful when skeletal maturity has to be appraised on a single cephalogram and only the second through fourth cervical vertebrae are visible.
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Other methods of skeletal assessment Frontal sinus development :- Sabine Ruf & Hans Pancherz ( 1996 AJO Nov)
Lateral radiographs were oriented with the nasion sella line horizontally. The peripheral border of the frontal sinus was traced, and the highest (Sh) and lowest (S1) points of sinus extension relative to the nasion sella line were marked. Perpendicular to the interconnecting line (Sh-S1), the maximum width of the frontal sinus was assessed The average yearly growth velocity (millimeters per year) of the frontal sinus was calculated separately for each of the prediction intervals (Tl or T2). .
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From longitudinal growth data of the subjects, the average yearly body height growth velocity (millimeters per year) was calculated. The maximum body growth velocity at puberty was assigned as body height peak (Bp). The body height growth data were used only to test the accuracy of the prediction of pubertal stage as assessed from frontal sinus development. • Frontal sinus growth velocity at puberty is closely related to body height growth velocity. • Frontal sinus growth shows a well-defined pubertal peak (Sp), which on the average, occurs 1.4 years after the pubertal body height peak (Bp). • In male subjects, the average age at frontal sinus peak is 15.1 years. • In a l-year observation interval, a peak growth velocity in the frontal sinus of at least 1.3 mm/yr. is attained by 84% of the subjects • In a 2-year observation interval, a peak growth velocity in the frontal sinus of at least 1.2 mm/yr. is attained by 70% of the subjects www.indiandentalacademy.com
Disadvantage:The presented prediction procedure for somatic maturity stage will not be able to replace hand-wrist radiographs in routine orthodontic diagnostics.
Advantage:It may deliver important information with respect to the person's stage of somatic development when two lateral head films are available spaced approximately 1 to 2 years apart
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Midpalatal suture ossification:Revelo & Fishman ( 1994 AJO Mar) performed a study to determine whether a positive correlation exists between adolescent maturational development & the approximation of the mid palatal suture.
Stages of ossification of the midpalatal suture were compared with Fishman's standards of skeletal maturation indicators (SMI stages 1 to 11), allowing for comparison of the differences of maturational development between delayed, average, and accelerated maturation,
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The following key landmarks and planes were identified: Point A, most anterior point of the premaxilla; Point B, most posterior point on the posterior wall of the incisive foramen; and Point P, point tangent to a line connecting the posterior walls of the greater palatine foramens . Measurements of length and associated percentage of osseous development were recorded for the following dimensions: A-P (total dimension of the suture), A-B (anterior dimension of the suture), and B-P (posterior dimension of the suture). www.indiandentalacademy.com
Clinical Implications Maturational development related to the midpalatal fusion can provide information about the treatment timing for maxillary expansion. This study reveals that for the expansion forces to physically open an approximated suture – the best time would be before SMI 9 as the % of approximation is less. The ideal time to initiate orthopedic expansion is during the early maturational stage corresponding to SMI 1 to 4. During this period less orthopedic force values might be required. This study has also verified the fact that mid-palatal approximation occurs more posteriorly during the entire adolescent period. Therefore Orthodontic mechanics could probably be more efficiently designed if more force value is expressed more posteriorly to the suture!!! www.indiandentalacademy.com
Antegonial notch as indicator of growth potential I) Singer, Mamandras, and Hunter (AJO 1987 Feb) performed a study to evaluate the effectiveness of Antegonial Notch in predicting Mandibular growth. They further stated that, Deep notch cases had more retrusive mandibles with a shorter corpus, smaller ramus height, and a greater gonial angle than did shallow notch cases. The lower facial height in the subjects with a deep mandibular notch was found to be longer, and both the mandibular plane angle and facial axis were more vertically directed. www.indiandentalacademy.com
During the average 4-year period, they found the deep notch sample experienced less mandibular growth as evidenced by 1) a smaller increase in total mandibular length, 2) corpus length, and 3) less displacement of the chin in a horizontal direction than did the shallow notch sample. The results of this study suggest that the clinical presence of a deep mandibular antegonial notch is indicative of a diminished mandibular growth potential and a vertically directed mandibular growth pattern. www.indiandentalacademy.com
II) Ronald, Thomas E. Southard, Karin A. Southard (AJO 2002 Apr)
Performed the investigation to test the hypothesis that the antegonial notch depth is a useful predictor of facial growth in a longitudinal sample of untreated growing patients selected at random.
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Linear & Angular measurements measured were 1) Notch depth Linear distance measured from the greatest point of convexity in the antegonial notch to the line connecting ACP with Igo along a line perpendicular to the ACP-Igo line (Figure 3) 2) Y-axis Anterior-inferior angle formed between the lines connecting porion with orbitale and sella with gnathion 3) SN-MP Angle formed between the line connecting sella with nasion and inferior gonion with menton 4) ANB Angle formed between the N-A point and N-B point lines 5) A-Pointx Linear distance from sella to A-point along the x-axis 6) A-Pointy Linear distance from sella to A-point along the y-axis 7) B-Pointx Linear distance from sella to B-point along the x-axis 8) B-Pointy Linear distance from sella to B-point along the y-axis 9) Pogonionx Linear distance from sella to pogonion along the x-axis 10) Pogoniony Linear distance from sella to pogonion along the y-axis 11) Mentonx Linear distance from sella to menton along the x-axis 12) Mentony Linear distance from sella to menton along the y-axis www.indiandentalacademy.com
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Conclusion:As notch depth decreased, more horizontal jaw growth was observed. Conversely, as notch depth increased, less horizontal jaw growth was observed, but the strength of this relationship was weak & concluded that antegonial notch depth fails to sufficiently indicate future Facial growth to warrant its application as a growth predictor
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Ricketts Growth Prediction Ricketts in 1955 AO, proposed a method for estimating the facial growth based on which a treatment plan could be formulated for a patient. He divided the investigation into 2 parts,wherein the 1 st part dealt with cephalometric procedures & findings culminating in the application of a single head film for the estimation of growth & treatment changes. The Basion www.indiandentalacademy.com – Nasion plane was taken as the
The following were determined:-
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The second part deals with a study of Facial esthetics.
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Clinical Implications of Growth:-
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C-Axis and maxillary growth:Definition :- C axis is defined as the line from Sella (s) to M-point . M-point – proposed by Merill & Nanda, it’s a constructed point representing the center of the largest circle that is tangent to the Superior, Anterior & Palatal surfaces of the Maxilla This C-Axis is studied to quantify the anterior & www.indiandentalacademy.com
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M point is determined using a specially designed template containing a no. of circles whose diameter increases in 1mm increments. The best fit circle that is tangent to the surfaces of the maxilla mentioned is selected. The line from Sella – M point is drawn & termed as C-axis.
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The authors conclude that, C-axis permits quantification of a complex maxillary growth process in cephalometric terms relative to various craniofacial structures in the sagittal plane. This has been performed from 7.4yrs to 18.75 yrs for both males & females. They found that up to the age of 14, males & females display avg. yearly growth increments of 1.14mm & 1.31mm respectively. www.indiandentalacademy.com
After the age 14, growth increments in females decreases & ceases at 16 years. Whereas for males it’s linear throughout the range of time studied.
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The Effect of Frankel II and Modified Twin Block Appliances on the ‘C’-axis: performed a study to evaluate the changes of dentomaxillary complex ‘s growth vector related to FR II & the Modified Twin Block appliances.
Stanley Braun, Nelson R. Diers, Gabriel ( AO 2004 )
The patients were chosen a) Females between 7.4 – 14 yrs, b) Males between 7.8 to 15.6 yrs c) Females – 11 – 14.3 yrs d) Males – 11.5 – 16.3 yrs.
For FR II group
For Twin Block group
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They conclude that The growth axis (‘C’-axis), which describes the growth vector of the dentomaxillary complex is not altered in any clinically meaningful manner through the use of either the Frankel II or the modified Twin Block appliances. They have reported that any positive changes found in the correction of Class II malocclusions are due to dentoalveolar changes fortified by relatively favorable mandibular growth. www.indiandentalacademy.com
Jaw Rotation & Tooth Eruption:In the short face individuals, the internal rotation pattern of the mandible is forwards & this alters the eruption path of the incisors more posteriorly for a tendency towards deep bite. The rotation also progressively uprights the incisors, displacing them lingually & causing a tendency towards crowding. In long face individuals, openbite will develop as anterior facial height increases unless the incisors erupt for an extreme distance. www.indiandentalacademy.com The rotation of the jaws also carries the incisors
Clinical significance of Jaw rotation According to Bjork 1969, In forward rotation of the jaw, the fulcruming point is located at the incisors. In patients where the incisor contact is stable the overbite remains unchanged. In unstable cases, the fulcruming point is located further back along the occlusal plane, resulting in deepening of the bite combined with greater increase of the posterior facial height. www.indiandentalacademy.com
Occlusal deterioration continues throughout the growth periods. Therefore deep bite should be treated early & the occlusion supported throughout the growth period. Retention should be maintained till mandibular growth is completed.
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Timing of Cervical H.G treatment Kopecky & Fishman (1993 AJO Aug) performed a study to determine a skeletal maturation period when maxillary cervical head gear can be optimally used for Orthopedic movement. They assigned each record to the maturational stage of Fishman. They conclude that, 1) Greatest skeletal correction is obtained during the periods of greatest growth velocity between the matruational stages SMI 4-7. 2) If maximal skeletal retraction is the objective, treatment can be initiated during the stages of SMI 1-3 & continued during SMI 4-7. www.indiandentalacademy.com
Benefits Of Early Class II Treatment Camilla Tulloch Et al ( 1998 AJO Jan) conducted a randomized clinical trial to test whether 2 phase treatment had any advantages when compared to the conventional methods. They collected Pre adolescent children with overjet greater than 7mm and assigned them to 3 groups. They found that the children under the functional group had attained better results in the 1st phase thereby the 2nd phase of treatment with fixed appliance yielded better results. They concluded that children treated early did not need the option of orthognathic surgery as they had better results with 2 phase therapy. www.indiandentalacademy.com
Franchi, Bacetti & McNamara ( 2004 AJO Nov), conducted a study to evaluate the treatment timing for RME & Face Mask therapy in post pubertal children. They found out that early treatment with RME, FM at the early Mixed / late deciduous dentition was more effective than treating in the late mixed dentition. Kapust et al ( 1998 AJO) compared 3 groups of children of different age groups to find out the cephalometric changes of treatment with RME , FM therapy. They conclude that children 4 -10 yrs of age respond better to treatment than those between 10 – 14 yrs of age. www.indiandentalacademy.com
Timing for effective application of anteriorly directed orthopedic force to the maxilla. Daniel Merwin, Peter Ngan, Urban Hagg , ( 1997 AJO Sep), conducted a study in children below & above 8 yrs to evaluate the efficacy of RME, FM therapy. Results indicated strikingly similar response between the younger & the older age groups. Thereby they concluded that Similar type of response can be obtained with RME, FM therapy whether it’s started before 8 yrs / afterwww.indiandentalacademy.com 8 yrs.
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Conclusion:If utilized properly hand-wrist radiograph and cervical vertebra radiograph provide a reliable and efficient means for assessing the individual’s growth scheme. By Modifying Growth at the appropriate time better treatment results could be obtained. Proper treatment plan formulation based on the growth status of the patient done prior to the start of the treatment will always lead to success !!! www.indiandentalacademy.com
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