Progressive inability to open the mouth since childhood

§Chief complaint

Cannot open the mouth; face has grown asymmetrically

§Medical & dental history

• 01Fall from a height at age 4 with a chin laceration
• 02No systemic arthritis
• 03Multiple carious teeth; oral hygiene impossible due to limited access

§Clinical examination

• 01Maximum interincisal opening 5 mm with no translation
• 02Retruded chin, bird-face profile, mandibular deviation to the right
• 03Obstructive sleep apnoea symptoms reported by parents
• 04Severe caries and calculus throughout

§Figures

§Differential diagnosis

§Final diagnosis

Right unilateral bony TMJ ankylosis (Sawhney type III) with mandibular hypoplasia

Loss of translation with almost no interincisal opening after childhood condylar trauma, plus radiographic obliteration of the joint space by a bony mass, defines bony ankylosis. Facial asymmetry with a hypoplastic ramus confirms the childhood onset.

§Investigations

• 01CBCT and CT with 3D reconstruction — bony bridge between condyle and skull base
• 02OPG showing loss of joint space and shortened ramus
• 03Sleep study for obstructive sleep apnoea
• 04Nasendoscopy for airway planning

§Treatment plan

• 01Awake fibreoptic nasal intubation planned with anaesthesia
• 02Interpositional arthroplasty (gap arthroplasty with temporalis fascia flap)
• 03Ipsilateral coronoidectomy, plus contralateral coronoidectomy if opening remains under 35 mm
• 04Aggressive early physiotherapy from day 1
• 05Staged distraction osteogenesis or orthognathic correction of the deformity

§Surgical procedure

• 01Al-Kayat Bramley preauricular approach
• 02Resection of the ankylotic mass creating a 1.5 cm gap
• 03Temporalis myofascial flap interposition
• 04Intraoperative opening achieved 38 mm

§Follow-up & outcome

• 01Physiotherapy started on day 1 with a mouth-opening device
• 02Opening 32 mm at 6 months
• 03Orthognathic correction planned after growth completion

§Clinical pearls / learning points

• 01Re-ankylosis is prevented by an adequate gap, interposition and relentless physiotherapy, not by surgery alone.
• 02Always plan the airway with the anaesthetist before an ankylosis case.
• 03Correct the ankylosis first, then the resultant facial deformity.

§Related diseases

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