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Adrian Becker. Orthodontic Treatment of Impacted Teeth
Table of Contents
List of Tables
List of Illustrations
Guide
Pages
Orthodontic Treatment of Impacted Teeth
List of Contributors
Preface to the First Edition
Preface to the Second Edition
Preface to the Third Edition
Preface to the Fourth Edition
About the Companion Website
1 General Principles Related to the Diagnosis and Treatment of Impacted Teeth
Dental age
Assessing dental age in the clinical setting – the Jerusalem method
When is a tooth considered to be impacted?
Impacted teeth and local space loss
Whose problem?
The timing of the surgical intervention
Patient motivation and the orthodontic option
References
2 The Logistics of Orthodontic Treatment for Impacted Teeth
The anchor unit
Attachments
Lasso wires
Threaded pins
Orthodontic bands
Bonded attachments
Standard orthodontic brackets
A simple eyelet or button
Intermediaries/connectors
Elastic ties and modules versus auxiliary springs
Temporary anchorage devices. Bone anchor screw
Zygomatic plate
Ankylotic, infra‐occluded, implanted or otherwise non‐movable teeth as bone anchors
Magnets
References
3 Biomechanics for Aligning Ectopic Teeth
Basic principles
Statically determinate and statically indeterminate systems
Consistent and inconsistent systems
Appliances
The active units
Cantilevers
Cantilever for extrusion of buccal displaced canines
Cantilever for extrusion and buccal movement of palatally displaced canines
Composite TPA TMA cantilever
Stainless steel TPA cantilever combination
Cantilevers used as uprighting springs
Ballista springs/torsion springs
Elastics
NiTi closed‐coil springs
NiTi open‐coil springs
Using continuous NiTi wires
Creative wire bending using V bends between anchorage unit and ectopic tooth
Root springs (alpha–beta springs)
Torqueing auxiliaries/torque application
Anchorage
Useful adjuncts
Appendix: Colour code convention for moments and forces
References
4 Diagnostic Imaging for Impacted Teeth
Planar radiography. Periapical radiographs
Occlusal radiographs. Mandibular arch
Maxillary arch. Maxillary anterior occlusal
True (vertex) occlusal
Extra‐oral radiographs
Three‐dimensional diagnosis of tooth position
Parallax method
Radiographic views at right angles
Standardization
Computerized tomography
Cone beam computerized tomography
Cone beam computed tomography technology
Processing the scanned information
3D module
Case 1: Ways of imaging and their effect on tooth size
Case 2: Peeling, clipping and sculpting
Automatic tooth segmentation
Multi‐planar reconstruction
Case 3: Diagnosing Resorption
Case 4: Multi‐planar reconstruction for an incisor that is almost horizontal
Inferior dental canal marking
Case 5: Inter‐relations between the inferior dental canal and the first molar
ALARA. This leads us to explain the term ALARA – and what it means in practice [30]
References
5 Surgical Exposure of Impacted Teeth
A brief history of surgery in relation to the treatment of impacted teeth
Aims of surgery for impacted teeth
Surgical intervention without orthodontic treatment
Exposure only
Exposure with pack
Exposure with pressure pack
The surgical elimination of pathology. Soft tissue lesions
Hard tissue obstruction
Infra‐occlusion
The principles of the surgical exposure of impacted teeth
The open eruption technique
The closed eruption technique
Initiation of traction
Speed of eruption
The final treatment outcome
A Cochrane Collaboration systematic review
Partial and full‐flap closure on the palatal side
The relief of crowding to reduce canine displacement
A conservative attitude to the dental follicle
Pathological pressure necrosis
Bone graft and the impacted canine
Quality‐of‐life issues following surgical exposure
Cooperation between surgeon and orthodontist
The team approach to attachment bonding
References
6 Impacted Maxillary Central Incisors
Aetiology
Obstructive causes. Supernumerary teeth
Odontomes
Ectopic position of the tooth bud
Attitudes to treatment of obstructed central incisors
Phase 1 treatment considerations
Trauma and dilaceration
Diagnosis. Clinical examination
Palpation
Radiographic examination
Collecting clinical and radiographic records in practice
Treatment timing
Orthodontic appliances. An orthodontic appliance for use in the early mixed dentition
Bonding brackets to the deciduous teeth
Johnson twin‐wire arch appliance
Obstructive causes. Case 6.1: Bilaterally impacted central incisors due to obstruction by supernumerary teeth
What determines the end‐point of a phase 1 treatment?
Recommendations of the Jerusalem Group
Case 6.2: Maxillary incisor impaction and its relationship to canine displacement
Traumatic causes
Dilaceration
‘Classic’ recurring dilaceration
Case 6.3: A clinical view of the dynamic development of a ‘classic’ central incisor dilaceration
Research into the development of ‘classic’ central incisor dilaceration
Treatment in the early mixed‐dentition stage (phase 1)
Retention of the phase 1 treatment outcome
Case 6.4: Treatment in the early mixed dentition and the significance of its effect on the root shape of a dilacerate incisor
Treatment in the later mixed‐dentition stage and thereafter
Case 6.5: Treatment of a dilacerate incisor in the middle to late mixed dentition and the need for apioectomy
How much labial root torque should be attempted in phase 1?
Arrested root development
The impacted permanent incisor tooth with a poor prognosis: Extraction
The impacted permanent incisor tooth with a poor prognosis: Eruptive rehabilitation and alveolar ridge restoration
Case 6.6: Resolving the impaction of a severely damaged central incisor with a closed apex and a poor prognosis, for use as a provisional replacement in the medium to long term
Severe trauma causing arrested root development, with open root apices and non‐eruption of four maxillary incisors
Case 6.7: Resolving the impaction of severely damaged central and lateral incisors with open apices and poor prognoses, for use as provisional replacements in the medium to long term
Case 6.8: Resolving the impaction of severely damaged central and lateral incisors with open apices and a poor prognosis, for use as a provisional replacement, in a case with high caries incidence
Postscript
Root length
Surgical exposure
Type and height of periodontal attachment
Treatment duration
Relative bone height of the crestal alveolus
Preservation of vitality
Oral hygiene
References
7 Palatally Impacted Canines
Prevalence
Aetiology: Local causes of palatal displacement. Long path of eruption
Space‐occupying hard tissue entities of dental origin
Abnormally located adjacent teeth
Crowding
Non‐resorption of the root of the deciduous canine
Trauma
Soft tissue pathology
Normal development of the maxillary anterior teeth
The guidance theory of impaction
The genetic theory of impaction
Abnormality in the embryonic dental lamina and primary displacement of the tooth bud
Tooth transposition
Problems with the genetic theory of canine impaction
Associated clinical features
Complications of the untreated impacted canine. Morbidity of the deciduous canine
Cystic change in the follicle of the permanent canine
Crown resorption
Resorption of the roots of the incisors
Diagnosis
Inspection
Palpation
Preliminary radiography
Treatment timing
Prevention and interception
Extraction of deciduous teeth. Deciduous canines
Extraction as a means of prevention. First premolars
Lateral incisors
Orthodontic space opening
Rapid maxillary expansion
Mechano‐therapy
General principles of mechano‐therapy
Resorption of the roots of adjacent teeth and the ‘surgery first’ protocol
Creating space for the canine
The need for a practical classification of palatally impacted canines
The Jerusalem classification
Group 1
Planning the orthodontic strategy
Surgery
Problems that may be encountered
Complications
Rotation
Mesial crown displacement
Palatal root displacement
Group 2
Planning the orthodontic strategy
Surgery
Problems that may be encountered
Complications
Group 3
Surgical and orthodontic strategy
The buccal approach
The tunnel approach
The palatal approach
Group 4
Surgery
Planning the orthodontic strategy
Problems that may be encountered
Group 5
Canine‐first premolar transposition (CPm1)
Canine–lateral incisor transposition (I2C)
Orthodontic/surgery strategy
Gold chain or twisted steel ligature?
Group 6
Treatment duration
References
8 Buccally Impacted Maxillary Canines
Canines impacted in the line of the arch
Buccally displaced maxillary canines
Buccally ectopic canines in the absence of crowding
Buccally impacted canines with mesial displacement
Palatally impacted labial canines
The ‘window of opportunity’
Buccally impacted canines with distal displacement
References
9 Resorption of the Roots of Neighbouring Teeth
Impaction and the transition from deciduous to permanent dentition
Can resorption be equated with dental caries?
Prevalence of resorption
Aetiology, diagnosis and prevention
Treatment
Treatment options
First option: Extract the impacted tooth
Second option: Extract the resorbed tooth
Third option: Non‐extraction
Fourth option: ‘Wait and see’
The anatomical context
The surgical context
The orthodontic context
Exposing the impacted tooth without devitalizing the adjacent tooth
Case 9.1: Poor radiography causes belated diagnosis
Can the resorbed tooth be moved without causing further resorption?
Case 9.2: Treatment in the presence of root resorption – when should treatment be discontinued?
Severe incisor root resorption
Treatment of severe incisor root resorption
Case 9.3: Is cone beam imaging appropriate for a case of severe incisor root resorption
Case 9.4: Long‐term regeneration and recovery after severe incisor root resorption caused by enlarged dental follicles
Treatment priority planning
The limits of conservative treatment for severe incisor root resorption
Case 9.5: Severe incisor root resorption and the limits of the orthodontic modality for successful treatment
A critical look at the treatment options
Stage 1
Stage 2
Stage 3
A post facto overview of the case
Postscript
References
10 Resorption of the Impacted Tooth
Invasive cervical root resorption
Diagnosis. Case 10.1: Invasive cervical root resorption in association with long‐term infra‐occlusion (see Online PPT & video chapter 10 Case A and D)
The importance of a clinical examination to invasive cervical root resorption diagnosis (see Online PPT & video chapter 10 Case C)
Case 10.2: Progressive infra‐occlusion caused by invasive cervical root resorption
Case 10.3: The ‘red herring’ case
Case 10.4: The unresorbed predentine layer
Case 10.5: Invasive cervical root resorption causing a lateral open bite
Cases 10.6 and 10.7: Invasive cervical root resorption in the furca of a molar in two unrelated individuals (see Online PPT & video chapter 10 Cases A and D)
Case 10.8: A case of historical interest
Principles of treatment aimed at salvaging the impacted tooth
Case 10.9: Severe loss of anchorage
Re‐evaluation of the case
Pre‐eruptive intra‐coronal resorption
Case 10.10 The pinhole lesion
Case 10.11: The disappearing tooth
Case 10.12: Unerupted mandibular permanent second molar
Case 10.13: Impacted dilacerate maxillary central incisor
Case 10.14: Unerupted maxillary permanent canine
Age‐related replacement resorption
References
11 Impacted Permanent Molars
Maxillary first permanent molars
The three elements of treatment
Case 11.1: A removable appliance
Mandibular first permanent molars. Case 11.2: Impacted mandibular first molar of unknown aetiology
Case 11.3: Impaction of second deciduous molar and first permanent molar due to soft tissue pathology
Mandibular second permanent molars
Local treatment
Case 11.4: Impaction due to overlying cystic pathology
Resolution of the impaction as part of a comprehensive orthodontic treatment plan
Case 11.5: Distally tipped first molar, horizontally impacted second and third molars
Maxillary second molars
Case 11.6: Extracting the impacted second molars
Maxillary ‘banana’ third molars and second molar impaction
Case 11.7: Impaction treated by elimination of the adjacent banana third molar
Mandibular third molars
Infra‐occlusion of permanent teeth. Case 11.8: An infraoccluded mandibular molar of unknown aetiology
Primary failure of eruption
References
12 Premolars and Mandibular Canines
Mandibular canines
Migration, transmigration and transposition
Mandibular second premolars. Crowding and space loss
Abnormal premolar orientation
Case 12.1: The ignored impacted mandibular premolar
Maxillary second premolars
Infra‐occlusion of deciduous teeth and its influence on premolar successors
Case 12.2: Infra‐occluded deciduous molars, impacted and missing premolars
Infra‐occluded teeth cause arrest of vertical bone growth
Case 12.3: Infra‐occluded deciduous molars and arrested bone growth
Case 12.4: All you need is space, patience and a good surgeon
Case 12.5: Severely infra‐occluded deciduous teeth: Think biology, not mechano‐therapy
References
13 The Root Form of Impacted Teeth
Normal root development
The aetiology of hooked root apices
The ‘hooked root’ theory of tooth impaction
Abnormal root form
Infra‐occluded deciduous molar obstructing a mandibular premolar
Odontoma
Permanent tooth obstruction
Dentigerous cyst
Invasive cervical root resorption
Pre‐eruptive intra‐coronal resorption
Trauma
Benign tumours and other soft tissue lesions
Cleidocranial dysplasia
Idiopathy
Case 13.1: Impaction, retarded eruption and consequent over‐eruption of posterior permanent teeth
Case 13.2: Twelve deciduous and twenty unerupted permanent teeth at age 16
Fake causes
Case 13.3: Roots of unerupted permanent first molar entangled in inferior alveolar nerve and vascular bundle
References
14 Rescuing Teeth Impacted in Dentigerous Cysts
Dentigerous cysts
Radicular cysts
Treatment principles. Surgery
Case 14.1: Was it necessary to extract the adjacent tooth?
The prognosis of teeth that have been severely displaced by cysts
Case 14.2: Cyst resolution and autonomous alignment
Case 14.3: Cyst resolution and autonomous alignment
Case 14.4: Transposition, three teeth at a time
Case 14.5: From pre‐phase 1 surgery to phase 2 orthodontics
Eyelets or brackets?
Conclusions
References
15 Impacted Teeth in the Adult Patient
Neglect and disguise
What does the literature say?
The impacted maxillary central incisor
Management
The need for temporary prosthesis during the treatment. Replacing a missing incisor
The soldered palatal arch
The impacted maxillary canine
Limited treatment goals
Case 15.1: Dilacerate incisor impaction and total space loss
Maximizing the anchor unit with fewer teeth. Case 15.2: Simple, effective and bracketless intermaxillary anchorage
Case 15.3: An impacted central incisor due to a midline supernumerary ‘tooth’
Implant anchorage. Case 15.4: Erupting an impacted molar and intruding its over‐erupted antagonist: Defying Newton
References
16 Lingual Appliances, Implants and Impacted Teeth
The context of impacted canines vis‐à‐vis the lingual appliance
Differences in treatment approach engendered by the use of lingual appliances
Canine traction, eruption and alignment
Finishing procedures
Anchorage considerations
Integrating implants with lingual appliances
Conclusion
References
17 Clear Aligners in the Treatment of Impacted Teeth
The beginning of an era
Case 17.1: Bilateral palatal impacted canines with constricted maxilla and functional shift
Case 17.2: Skeletal and dental class III with anterior and posterior cross‐bite and palatal impacted upper right canine
Mechanical principles of the aligner
Digital planning software
Managing impacted teeth with clear aligners
Methods of regaining space with clear aligners
Sequential distalization/mesialization
Expansion
Proclination
Interproximal enamel reduction
Root movement
Impacted tooth traction while using clear aligners
Timing and staging
Accelerated tooth movement
Biomechanics aspects
Clear aligner intra‐oral elastics interface
References
18 The Anatomy of Failure
Why is it important to know the cause of the failure of the tooth or teeth to erupt?
Patient‐dependent factors. Age
Medication
Abnormal morphology of impacted and adjacent teeth
Pathology affecting the impacted tooth
Grossly ectopic teeth
Lack of compliance
Radiologist‐dependent factors
Orthodontist‐dependent factors. Incorrect positional diagnosis
Negligent examination of clinical and/or radiographic features
Resorption of the root of an adjacent tooth
Case 18.1: Aggravating an inherent resorption tendency by inappropriate directional traction
Poor anchorage
Case 18.2: Loss of anchorage due to resistance of the palatal mucosa to re‐eruption of the tooth
Case 18.3: Acute mucosal/periodontal inflammation in a high‐vaulted palate, due to inadequate vertical extrusion of a palatally impacted canine before applying horizontal traction to the labial archwire
Case 18.4: Rapid eruption of the canine following re‐exposure of the canine crown causing over‐eruption
Inefficient and poorly designed appliances
Iatrogenic causes of failure
Case 18.5: Hidden dangers of space opening for impacted canines
The core of the problem
Case 18.6: Bilateral developmental disturbance in the eruption path of maxillary canines
Case 18.7: Interceptive uprighting of incisor root to avert maxillary canine impaction
Surgeon‐dependent factors. Poor surgical planning and mistaken positional diagnosis. Case 18.8: The surgeon could not find the canine
Case 18.9: A dilacerate central incisor, for which the surgeon bonded a bracket to the palatal root apex
Surgical exposure without prior orthodontic planning
Case 18.10: Iatrogenic damage due to radical repeated surgical exposure without orthodontic involvement
Case 18.11: Botched surgery
Mid‐treatment alternate consultations – second opinions
References
19 Traumatic Impaction
Acute traumatic intrusion (intrusive luxation)
Spontaneous re‐eruption
Manipulative/surgical repositioning and splinting
Orthodontic reduction
Orthodontic treatment considerations
Indications for the different types of orthodontic appliance. Modified Hawley appliance
Bonded wire frame
Self‐supported labial arch on fixed molar bands
Palato‐labial partial avulsion
Conclusion
References
20 Extreme Impactions, Unusual Phenomena, Difficult Decisions
Case 20.1: Monster tooth, supernumerary tooth, impacted central incisor and the maxillary midline
Case 20.2: Bilaterally impacted maxillary canines in a patient suffering with aggressive juvenile periodontitis
Case 20.3: Labially impacted maxillary canine at the level of the nasal floor
Case 20.4: The inaccessible canine
Concerns with the impacted canine
Accurate positional diagnosis
Treatment planning in light of the inaccessible canine
Treatment
Case 20.5: Severe trauma in infancy: repairing the damage with orthodontics
Case 20.6: Labial to the lateral incisor and lingual to the central incisor
Case 20.7: Three adjacent impacted molars
Treatment options
Diagnosis and treatment plan
Treatment
Treatment duration and outcome
Case 20.8: Five unerupted teeth in the walls of a dentigerous cyst
References
21 Cleidocranial Dysplasia
Clinical features and dental characteristics
Diagnosis
Treatment modalities
Prosthodontics
Surgical relocation
Orthodontics and surgery
The Toronto–Melbourne approach
Limitations
The Belfast–Hamburg approach
Limitations
Understanding the problem
The Jerusalem approach
Recognition of the clinical features
What about the skeletal class III relationship in cleidocranial dysplasia patients?
What management protocol can be used to achieve this level of compliance?
Constructing a custom orthodontic/orthopaedic face mask
The intra‐oral appliance
Connecting it all together
Erupting the permanent teeth
Surgical therapeutic measures
Intervention 1
Intervention 2
Orthodontic strategy
Preparing the patient
The Jerusalem approach in clinical practice. Stage 1: Ensuring the health of the dentition
Stage 2: Vertical correction in the incisor region
The initial orthodontic set‐up
Surgery in stage 2
Orthodontics in stage 2
Stage 3: Horizontal (a–p) correction in the incisor region. Orthodontics in stage 3
Stage 4: Vertical correction in the posterior region
Surgery in stage 4
Stage 5: Correction of the root orientation. Orthodontics – eruption mechanics
Extreme tooth movement
Retention of the treated result
Orthognathic surgery
References
Index
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