Spear's Ankylosis eBook

A N KY LO S I S

BY GREGGORY KINZER, D.D.S., M.S.D.

Spear Education provides dental continuing education for striving dentists that are dedicated to the pursuit of clinical excellence in dentistry

CONTENTS

A L L C O N T E N T S © 2 0 2 0 S P E A R E D U C AT I O N

A N KY LOS I S

4

Part I: Etiology and Considerations

6

Part II: Treating Adults With an Ankylosed Tooth

10

Part III: Treating Children With Ankylosed Permanent Teeth

14

Part IV: The Use of Decoronation

18

Part V: Autotransplantation

PA R T I : ET I O LO GY A N D CO N S The ankylosis of a tooth is defined as an anatomical fusion of alveolar bone with cementum and can occur any time during eruption, either before or after the tooth erupts into the oral cavity. Essentially, the periodontal ligament is obliterated by a ‘bony bridge’ and the root becomes fused to the alveolar bone.

An ankylosed tooth can be diagnosed multiple ways: • A lack of mobility or a sharp, solid sound upon percussion with a hand instrument (typically only reliable when at least 20 percent of the root is affected) • The incisal or occlusal edge is below the incisal/occlusal plane • The gingival margin or, more accurately, the CEJ is at a more apical position compared to the adjacent teeth • Radiographic examination reveals obliteration of the periodontal ligament space

Figure 1

A N KY LOS I S

S I D E R AT I O N S SO WHAT IS THE

By far, the most common theory

CONCERN WITH

traumatic injury of the periodontal

that is known to cause ankylosis is

ANKYLOSED TEETH?

ligament (Kracke: 1975, Henderson:

The first concern is that the

ankylosis is highest for teeth with

ankylosed root is continually

subluxation or avulsion injuries

resorbed and replaced with bone,

because of the nature and severity of

thereby diminishing the support

damage to the periodontal ligament.

1979, Andreasen: 1981). Risk of

of the crown of the tooth – although

Deciduous teeth become ankylosed

the rate of the resorption may be

far more frequently than do

extremely variable.

permanent teeth, the ratio being

The second is the impact on

greater than 10-to-1, and lower teeth

normal alveolar development if an

are ankylosed more than twice as

ankylosed tooth is present while

often as upper teeth.

the patient is undergoing growth.

Although the initial treatment

The ankylosed tooth will appear as

thought when an ankylosed tooth is

if it is becoming submerged as the

encountered is often to immediately

adjacent teeth erupt.

extract the ankylosed tooth, the

Several theories have been proposed

actual treatment decision should be

on the different etiologies that may

made only after evaluating multiple

cause ankylosis:

different factors:

• A disruption of local metabolism

• Whether the ankylosed tooth

of the PDL (Biederman: 1962)

is deciduous or permanent

• Genetics (Kural, Magnusson: 1984)

• The time/age of the onset of ankyloses

• Deciduous teeth without a permanent successor

• The time/age at diagnosis;

(Brearly, McKibben: 1972)

patient gender • The location of the affected tooth • The smile line In the subsequent posts, I will look deeper into the different treatment recommendations and options given the variety of clinical findings that may be present.

5

PA R T I I : T R E AT I N G A D U A N A N KY LOS E D TO OT H Several factors need to be taken into consideration when deciding on the appropriate treatment option for an ankylosed tooth. These factors include: • Whether the ankylosed tooth is deciduous or permanent; • The time/age of the onset of ankylosis • The time/age at diagnosis • Patient gender • The location of the affected tooth • The patient’s smile line.

It is known that the root of the ankylosed tooth will typically undergo continual resorption and subsequent replacement with bone. In addition, depending on when the tooth ankylosed, a hard/soft tissue defect in the area of the ankylosed tooth will be present if the tooth became ankylosed prior to the completion of growth and development.

If, however, the tooth became ankylosed after growth was complete, there may be no impact on the hard and soft tissue positions. This patient is in her late 50s and has tooth #9 ankylosed. Given the position of the gingival margin and incisal edge of this tooth compared to other teeth in the arch, it is apparent that it became an ankylosed tooth at some time prior to the completion of growth.

(Figure 1)

Figure 1

A N KY LOS I S

U LT S W I T H H In contrast, this patient in his

If the treatment chosen is to keep the

mid-30s also has tooth #9 ankylosed,

ankylosed tooth, many options exist:

but the gingival margin is level with

• Keep the tooth and restore in its

the adjacent central incisor, leading

current position;

us to conclude that it became an

• Subluxate the tooth and

ankylosed tooth after growth was

orthodontically reposition into

completed. (Figure 2)

the desired location; • Move the ankylosed tooth into the correct position using a segmental osteotomy containing the ankylosed tooth.

If the patient has a low smile line – or the gingival margin position is still correct – and the rate of resorption

Figure 2

is slow, keeping and restoring the ankylosed tooth in its current

When treatment planning an

position is a simple way to improve

ankylosed tooth in an adult, it must

the esthetics. The unknown of this

be stated that the ankylosed tooth

treatment option, though, is how long

does not need to be extracted just

with the tooth will last before the

because it is ankylosed. If you think

resorption advances to the point that

about it, an ankylosed tooth is not

the tooth structurally needs to be

that dissimilar from an osseointegrated

extracted. Even though there is a

implant. The treatment decision

significant gingival margin discrepancy

on whether to keep the ankylosed

on the ankylosed tooth #9, the impact

tooth – and possibly restore it – or

on the overall esthetics is low because

remove it, will depend on the esthetic

of the patient’s low smile. (Figure 3)

impact of any hard/soft tissue defect and the rate at which the resorption is occurring.

Figure 3

7

Given that the resorption is occurring at

If the ankylosed tooth is an esthetic

slow rate – the tooth became ankylosed

issue and the rate of the resorption is

prior to the completion of growth and

advancing quickly, extraction of the

the patient is now in her late-50s – the

tooth is recommended. The area will

treatment plan was just to restore the

typically require augmentation with

incisal edges of #8, #9 and #10 with

either hard or soft tissue depending if

composite. The composite restorations

the final restoration is a single tooth

were in place approximately 10 years

implant or a tooth supported FPD.

before the resorption advanced to the

(Figures 5-6)

point that #9 required extraction.

(Figure 4)

Figure 4

Figure 5

Figure 6

Delve Deeper Into Your Referral Community Do you feel blocked from networking with like-minded peers in your referral network?

Spear Study Club has virtual tools and online resources to directly address your practice’s clinical needs, in addition to extensive educational content to explore with your entire interdisciplinary team.

Meet virtually or in-person, supported by Spear curricula that’s proven to help streamline case work and generate more consistently predictable patient outcomes. Ask us how to join a club in your community, or start your own today.

Learn More

Discover how Spear Study Club impacts your entire practice: 855.773.2772 | studyclub@speareducation.com | speareducation.com/study-club

PA R T I I I : T R E AT I N G C W I T H A N KY LOS E D P E As was mentioned in Ankylosis Part I and Part II, several factors need to be taken into consideration when deciding on the appropriate treatment option for an ankylosed tooth. When ankylosis is diagnosed in a child, these factors are even more important to evaluate prior to making the treatment decision.

These factors include: • Whether the ankylosed tooth is deciduous or permanent • The time/age of the onset of ankylosis • The time/age at diagnosis • Patient gender • The location of the affected tooth • The patient’s smile line Here we have a female patient that presented to the office at the age of 15 with tooth #8 ankylosed. (Figure 1)

Figure 1 This tooth was avulsed when she was 11 years old and re-implanted after being out of the mouth for approximately one hour. The desire of the patient and her family was to improve the esthetics. As you can see, the incisal edge and gingival margin are more apically positioned compared to the adjacent teeth.

A N KY LOS I S

CHILDREN ERMANENT TEETH THE ANKYLOSIS PATIENT

TREATMENT OPTIONS

• The tooth most likely ankylosed at

AND CONCERNS FOR THE

age 11 to 12

ANKYLOSED TOOTH

• The patient is now 15

The treatment options are:

• The patient is female

• Extract the tooth and prepare

Prior to figuring out what we should do,

for implant placement

there are still a few questions that we

• Subluxate the tooth and

need to address:

orthodontically reposition

• How fast is the resorption occurring?

• Use a segmental osteotomy to

As can be seen from the radiographs

orthodontically reposition to the

that the patient brought, the rate of resorption seems to be progressing

desired area

very slowly. (Figure 2)

• Leave the tooth in its current

• Where is the smile line? The patient

position and restore the esthetics

has a very low smile line and does

If the tooth is extracted, she will need

not show the FGM. (Figure 3)

hard tissue augmentation, will have to

• Where is she in relationship to her

wait until she is 17-years-old to have an implant placed, and we will need to

growth? Females generally are done

provide an interim tooth replacement

growing at the age of 17. Given that

option throughout this time period.

she is 15 years of age now, it is

The downside of this option, as far as

anticipated that she is near the end

the ankylosis patient and her family

of her growth phase.

are concerned, is that this is a very formidable time in her life. Managing appointments, schedules and interim tooth replacement would be difficult.

Figure 2 Figure 3

11

Subluxating the tooth and

Although the tooth could be extracted

orthodontically repositioning it into

now in preparation for a single tooth

the desired position will have limited

implant, the decision was made to

success depending on how much of

leave the tooth and restore the incisal

the tooth is ankylosed. This option

edge length with composite. (Figure 4)

typically works better on teeth that only have partial or spot ankylosis.

Using a segmental osteotomy to reposition the desired tooth can be successful depending on the surgical approach, but could be very problematic if necrosis of the segment were to occur.

What about leaving the ankylosed

Figure 4

tooth for now and improving the esthetics by adding to the incisal

The ankylosis patient and her

edge? Will this create more problems?

family knew that the composite was

What we already know is:

an interim restoration and that the

• The replacement resorption is occurring slowly (so it could possibly be maintained for another 5-10 years) • The patient is 15 and near the end of her growth phase (so the defect created by the ankylosis shouldn’t

tooth would require extraction and implant placement in the future. The question of when depends on the rate that the resorption progresses. In this patient, the tooth lasted another 10 years before it required extraction.

(Figure 5)

appreciably increase) • The patient has a low smile (so you don’t see the gingival margin discrepancy)

Figure 5

A N KY LOS I S

The Gateway to Great Dentistry Dentistry’s Most Innovative Online Learning Resource

Membership to Spear Online provides your entire practice team with: PATIENT EDUCATION

TEAM TRAINING AND MEETING RESOURCES

Make chairside case presentation more engaging with our new tablet app, or stream animated videos to your lobby monitors via Fire TV Stick and Apple TV — options designed to empower even the most hesitant patient to take ownership of their oral health.

Utilize tools designed for your front office, hygienists and assistants. When your staff understands and communicates the value of the dentistry you provide, patients are better informed and more receptive to accepting treatment.

CLINICIAN EDUCATION

SPEAR TALK

Increase your skills and earn continuing education credits on your own schedule with more than 1,500 clinical and practice management lessons presented by dentistry’s most respected clinicians.

Connect with thousands of like-minded colleagues in a safe, supportive, clinicianonly environment meticulously monitored by Spear faculty and contributing authors to find answers to any clinical or practice challenge.

Discover how Spear Online impacts your entire practice: 855.625.2333 | online@speareducation.com | speareducation.com/spear-online 13

PA R T I V : T H E U S E O F D E C O R O N AT I O N Typically when managing ankylosis in permanent teeth in children, it is advisable to remove the ankylosed tooth prior to significant growth so that the subsequent eruption of the natural teeth during growth doesn’t create a significant hard and soft tissue defect. However, as surgeons know all to well, trying to extract ankylosed teeth can be a difficult undertaking.

In this example, we have an 11-year-old male who received trauma to the maxillary anterior when he was 10 years old and subsequently had ankylosis of tooth #8.

(Figure 1)

Figure 1 As can be seen radiographically, the root resorption is occurring at a significant rate given that the trauma only occurred approximately one year ago. At this time though, there hasn’t been much change in the incisal edge or FGM positions. With this in mind, the tooth can be monitored.

The parents are informed that continued recalls are imperative so that the tooth can be extracted prior to formation of a significant hard and soft tissue defect. This must be stressed to the parents because if the patient gets lost in the system or doesn’t return for recalls the defect will become greatly amplified and the treatment needed to correct it will be more difficult. At the age of 12, a change in the incisal edge position and FGM location can be seen. (Figure 2)

Figure 2

A N KY LOS I S

DECORONATION AS A SOLUTION It was at this time that it was decided to

This will allow for the periosteum to

remove the ankylosed tooth prior to the

grow over the remaining root creating

continuation of growth. Mamlgren et al.

a periosteal sling between the adjacent

described a technique in a 2006 paper

teeth over the edentulous ridge and

that discussed the use of decoronation

underlying root. The creation of the

in circumstances such as this. (Figure

periosteal sling will allow some vertical

3) Rather than remove all of the tooth

ridge development in the edentulous

fragments, decoronation removes the

site due to the tension created by the

crown of the tooth approximately 1mm

eruption of the adjacent teeth, while

below the osseous crest. (Figure 4)

the remaining root continues to undergo replacement resorption.

(Figure 5)

Figure 3

Figure 4

Figure 5

15

This decoronation technique has been

If decoronation is considered in the

modified to include hollowing out the

growing patient, the key is that provide

internal of the root in addition to

the treatment prior to the patient

cutting off the coronal portion below

undergoing significant growth.

the osseous crest. The benefit of this is that the resorption will occur at a more rapid rate as it will be occurring from the internal as well as the external aspect of the root.

The difficulty in managing these patients with extraction of the ankylosed tooth is providing interim tooth replacement until the cessation of growth (this is especially true in males where growth may not be completed until 21-22 years of age). As can be seen though, when the patient is ready to undergo implant treatment, the ridge height is relatively good, making the management of the ridge more predictable for an implant or a pontic. (Figure 6)

Figure 6

Introducing Virtual Seminarsthe Spear Experience with Online Flexibility New format provides the same dynamic CE content as campus seminars – but with online flexibility The new virtual Spear Seminar format allows you to refine your clinical skills following the same lessons that you would at the Spear Campus in Scottsdale — but from anywhere, as a safe online alternative to large-attendance campus events.

Experience the same clinical dental CE seminars as you would in Scottsdale but in a virtual format that provides the comfort of intimate online engagement with faculty from your home or office.

What would your practice team like to accomplish next? Take part in a virtual seminar and you will be invited to return to experience the seminar in person when we reopen the Spear Campus.

Check upcoming dates and register for the Spear Virtual Seminar that works best for your schedule at SPEAREDUCATION.COM/VIRTUAL-SEMINARS

PA R T V : A U T O T R A N S P L A N TAT Typically when managing ankylosed teeth in children it is advisable to remove the ankylosed tooth prior to significant growth cycles so growth and subsequent eruption of teeth don’t create significant hard and soft tissue defects. However, the difficulty in managing these patients is providing interim tooth replacement until the cessation of growth. This is especially true in males when trauma occurs early in life (ie. age 9 to 11) and where growth may not be completed until 21 to 22 years of age.

This can be a considerable amount of time to manage the edentulous ridge and provide an interim restoration that doesn’t significantly impact them socially.

The main image shows a 10-year-old male patient with an ankylosed tooth #9 that is beginning to show signs of incisal edge and gingival margin asymmetry.

Figure 1

A N KY LOS I S

TION ANKLYOSIS AND

THE REQUIREMENTS

AUTOTRANSPLANTATION

NEEDED FOR

One option that I have previously

AUTOTRANSPLANTATION?

written about is the use of

The harvested tooth needs to have a

autotransplantation to manage these

root length that is two-thirds to fully

young patients. Autotransplantion is

developed and have an open apex.

a procedure that utilizes the patient’s

This will provide the most predictable

own teeth, typically the mandibular

transplant for retaining vitality as

second premolar, as a replacement

well as having continued root

for missing anterior teeth by extraction

development. Generally, the patient

and re-implantation. The transplanted

that has a mandibular second premolar

tooth can then serve as an esthetic

that meets these criteria is typically

and functional replacement for the

between the ages of 10-12. (Figure 2)

patient. The major concern for most dentists is: how predictable is this type of treatment?

A 2002 paper from the Am J Orthod Dentofacial Orthop (Czochrowska EM, et al.) entitled Outcome of Tooth Transplanation: Survival and Success

Figure 2

Rates 17-41 Years Post-treatment showed a 90% survival rate (with a mean observation time of 26 years).

By comparison with other treatment options, this is an extremely favorable outcome. However, it must be stated that the success rates is highly dependent on the skill and experience of the surgeon performing transplantations. I have been fortunate to work with Dr. Jim Janakievski in Tacoma, WA whom I consider to be one of the world experts in the area.

19

Hence, this treatment option has a narrow window of time where it is viable. The transplanted teeth placed in a similar position of eruption as they were in when harvested. (Figure 3) These teeth typically have continued root development and even maintain their vitality which can be attributed to their stage of root development at

Figure 3

the time of harvest.

The transplant tooth can be built up with composite and the patient can continue on with orthodontic treatment. (Figures 4 and 5) Although this is not a treatment option that needs to be utilized every day, it is wonderful to know

Figure 4

that autotransplantion can provide a predictable esthetic and functional replacement for these patients that would otherwise have to wait 10 to 12 years, until the completion of growth, before the implant can be placed.

Figure 5

ABOUT THE

AUTHOR A gifted academician and clinician, Dr. Kinzer’s interdisciplinary approach to dentistry is founded in empirical research and clinical experience.

His unique ability to impart complex clinical processes in a logical, systematic and understandable way differentiates him from other dental educators of our time.

Committed to advancing the art and science of restorative dentistry, Dr. Kinzer continues to serve as an affiliate assistant professor in the graduate prosthodontic program at the University of Washington School of Dentistry. He also taught with Dr. Frank Spear at the Seattle Institute for Advanced Dental Education from 1998-2009 prior to joining Spear Resident Faculty.

In addition, Dr. Kinzer has written numerous articles and chapters for many dental publications and serves on the editorial review board for the Journal of Esthetics and Restorative Dentistry. He maintains a private practice in Seattle limited to comprehensive restorative and esthetic dentistry.

Dr. Kinzer received his D.D.S. from the University of Washington in 1995 and an M.S.D. and certificate in prosthodontics in 1998.

Greggory Kinzer, D.D.S., M.S.D.

T H E P U R S U I T O F G R E AT D E N T I S T R Y Based in Scottsdale, Arizona, Spear Education is an innovative dental education company that includes the following practice-building, member-based services:

Spear Online

Spear Study Club

The “Gateway to Great Dentistry”

Involves small groups of peers that

includes more than 1,500 video

meet locally as many as eight times

lessons spanning restorative,

a year to collaborate on real-world

esthetics, occlusion, worn

cases, improve their clinical expertise

dentition, treatment planning and

and discuss growing practice

more. But access is not only for

profitability. Spear has the largest

dentist continuing education.

network of study clubs, with active

Membership provides the entire

clubs in more than 40 states and

office team with staff training, team

six countries.

meeting and patient communication tools — like the Patient Education platform and native apps, in addition to “Conversation Essentials” video vignettes — to align the entire practice on patient care.

A N KY LOS I S

Spear Masters Program Specialist Workshops

Spear Campus

With 2½-day workshops for

Scottsdale campus annually for seminars

both endodontists and surgical

and workshops. Members attend sessions

specialists tailored to meet the

in a state-of-the-art, 300-person lecture

needs of doctors and their teams,

hall and receive hands-on training in

you will learn how to strengthen

Spear labs.

Thousands of dentists visit Spear’s scenic

relationships with your referring practices, develop your team for growth and build the leadership skills necessary to streamline

Spear Faculty Club

case flow.

Designed as a prestigious community of doctors who share the journey to Great Dentistry with others. While all Faculty Club members demonstrate a commitment to continued learning,

Spear Practice Solutions

professional growth and providing the

The technology-enabled business

best patient care, many also serve as

and clinical solutions platform

Visiting Faculty and mentor attendees

blends custom education,

during campus seminars and workshops.

personalized coaching and real-time analytics to help your practice reach its full potential.

23