TMJ Disorders
TMJ Ankylosis
Bony or fibrous fusion of the mandibular condyle to the glenoid fossa producing limited or absent mouth opening; a paediatric-onset case causes 'bird-face' deformity.
§ figuresFigures (0)
Verified clinical image not yet available
Verified open-access images only, reproduced for education under their stated licences · no AI-generated or illustrative artwork · TMJ Ankylosis figures pending faculty review.
§ overviewOverview
Restriction of jaw movement caused by fusion of the mandibular condyle to the temporal bone through fibrous, bony or fibro-osseous tissue.
§ etiologyEtiology
- 01Trauma (most common — 50%)
- 02Infection (otitis media, osteomyelitis)
- 03Systemic (ankylosing spondylitis, rheumatoid)
- 04Radiotherapy
- 05Congenital
§ epidemiologyEpidemiology
Children and young adults; unilateral more common; more prevalent in developing countries due to untreated trauma/infection.
§ clinicalClinical Features
- 01Reduced or absent mouth opening
- 02Micrognathia (unilateral: chin deviation to affected side; bilateral: bird-face)
- 03Sleep-disordered breathing/OSA
- 04Poor oral hygiene, dental crowding
§ investigationsInvestigations
- 01OPG, PA cephalogram
- 02CT / 3D CT (gold standard for bony architecture)
- 03MRI to assess disc
§ classificationClassification
- 01Sawhney (1986): Type I fibrous, Type II fibro-osseous with condyle intact, Type III bony bridge with condylar destruction, Type IV extensive bony ankylosis obliterating architecture
§ treatmentTreatment
- 01Aggressive early release to prevent deformity and OSA
- 02Kaban protocol: (1) aggressive gap arthroplasty ≥1.5 cm, (2) ipsilateral coronoidectomy, (3) contralateral coronoidectomy if opening <35 mm, (4) interpositional material (temporalis flap or alloplastic), (5) rigid fixation with early mobilisation, (6) aggressive physiotherapy for ≥6 months
- 03Costochondral graft in growing children; TMJ prosthesis in adults
§ complicationsComplications
- 01Re-ankylosis
- 02Facial nerve injury
- 03Growth disturbance
- 04OSA
§ prognosisPrognosis
Good with strict adherence to Kaban protocol and physiotherapy; re-ankylosis if immobilised.
§ examKey Examination Points
- 01Measure MIO
- 02Assess airway (OSA)
- 03Type on CT
§ revisionQuick Revision Summary
- 01Sawhney classification · Kaban protocol · aggressive physio
§ vivaBDS Viva Questions
- 01Sawhney types?
- 02Kaban protocol?
- 03Choice of interpositional material?
§ mcqsMCQs — Assessment (3)
Question 1
Most common cause:
Question 2
Preferred graft in growing child:
Question 3
Sawhney Type III describes:
§ evidenceReferences & Evidence
Current Classification
WHO Classification of Tumours Online — Head and Neck
IARC / WHO · 2022
Continuously updated online edition of the WHO head and neck tumour classification.
Evidence summary
Highest level of evidence linked to this page: WHO / Official Classification.
- L1 · Classification — 1
- L2 · Guideline — 1
- L6 · Textbook — 3
1 linked source was published from 2024 onwards. Where guidance is limited or contested, rely on the higher-level sources above rather than this summary. Educational use only — not a substitute for clinical judgement.
Content last reviewed
September 2026
Evidence last reviewed
September 2026
Next scheduled review
September 2027
Review status
EVIDENCE REVIEWED
Search latest PubMed evidence
Last literature search: 7 September 2026
Current Classification
IARC / WHO. IARC · 2022
Continuously updated online edition of the WHO head and neck tumour classification.
Clinical Guidelines
Schiffman E, Ohrbach R, Truelove E et al.. Journal of oral & facial pain and headache · 2014 · 28(1):6-27
International consensus diagnostic protocol (Axis I/II) for temporomandibular disorders, validated for clinical and research use.
Histopathology References
Barnes L. CRC Press · 2008
Detailed histopathological reference for head and neck diagnostic criteria.
Textbook References
Neville BW, Damm DD, Allen CM et al.. Elsevier · 2024
Standard reference textbook of oral and maxillofacial pathology used throughout this atlas.
Rajendran R, Sivapathasundharam B. Elsevier · 2020
Undergraduate and postgraduate oral pathology textbook widely used in BDS and FCPS curricula.
Additional sources cited on this page
- Kaban LB. J Oral Maxillofac Surg 2009
Draft — pending faculty review. Educational use only; verify against current guidelines and primary sources before clinical application.