Progressive inability to open the mouth after childhood trauma

§Chief complaint

Cannot open the mouth; difficulty eating and cleaning teeth since childhood

§Medical & dental history

• 01Fall with chin injury aged 5; no treatment sought
• 02Rampant caries from inability to clean; crowded dentition

§Clinical examination

• 01Maximum interincisal opening 5 mm with no translation
• 02Facial asymmetry with chin deviated to the left and a reduced left ramus height
• 03Antegonial notching on the left; obtuse mandibular angle
• 04No condylar movement palpable on the left; right joint translates normally
• 05Severe caries and calculus; class II retrognathic profile

§Figures

§Differential diagnosis

§Final diagnosis

Left bony temporomandibular joint ankylosis (Sawhney type III) with mandibular hypoplasia

Complete loss of translation with a radiographically fused condyle-fossa complex following childhood condylar trauma, plus asymmetric mandibular growth deficiency, confirms bony ankylosis requiring gap arthroplasty with interposition and aggressive physiotherapy.

§Investigations

• 01CT with 3D reconstruction to map the ankylotic mass and its relation to the skull base
• 02Airway assessment and anaesthetic planning for a difficult intubation
• 03Cephalometric analysis and study models for later orthognathic planning

§Radiology

• 01CT — dense bony bridge between the left condyle and glenoid fossa, joint space obliterated
• 023D reconstruction — shortened left ramus, antegonial notching
• 03OPG — elongated coronoid process on the affected side

§Treatment plan

• 01Awake fibreoptic nasal intubation
• 02Gap arthroplasty with interpositional temporalis myofascial flap; ipsilateral and contralateral coronoidectomy as needed to achieve 35 mm opening intraoperatively
• 03Immediate aggressive physiotherapy from day 1
• 04Later distraction osteogenesis or orthognathic surgery for the skeletal deformity

§Surgical procedure

• 01Preauricular approach with temporal extension, facial nerve protected
• 02Ankylotic mass excised creating a 15 mm gap; ipsilateral coronoidectomy, then contralateral coronoidectomy via intraoral access
• 03Intraoperative opening 38 mm achieved; temporalis myofascial flap turned down as interposition

§Follow-up & outcome

• 01Day 1 — mouth-opening exercises begun with a screw device
• 023 months — opening 32 mm maintained
• 0312 months — opening 34 mm, caries treated, orthodontics started

Outcome: Functional mouth opening restored and maintained at 1 year with committed physiotherapy; skeletal correction planned.

§Discussion

• 01Re-ankylosis is the main complication and correlates directly with inadequate gap size, failure of interposition and poor physiotherapy adherence.
• 02Childhood condylar injury can arrest mandibular growth, producing the classic bird-face deformity in bilateral cases.
• 03Total joint replacement is an option in adults with recurrent ankylosis.

§Clinical pearls / learning points

• 01Physiotherapy is as important as the surgery — start on day one.
• 02Aim for at least 35 mm of intraoperative opening; add coronoidectomy if needed.
• 03Plan the airway before anything else.

§Viva questions

§MCQs

§Related diseases

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