Single-stage Correction of Unilateral TMJ Ankylosis and Associated Micrognathia: A Case Report

Introduction Temporomandibular Joint (TMJ) ankylosis is a debilitating condition that can lead to severe functional limitation and dentofacial deformities. We report a case of a young adult male with unilateral left bony TMJ ankylosis, presenting with a Class II Division 1 malocclusion on a Class II skeletal base, marked mandibular retrognathia (micrognathia) with chin deficiency, and facial asymmetry. Case Presentation A 16-year-old male presented with a 10-year history of restricted mouth opening following trauma (fall from a bicycle). Clinical and radiographic evaluation revealed left-sided bony TMJ ankylosis with associated facial asymmetry, chin deviation, and micrognathia. Mouth opening was limited to 4 mm. The patient underwent interpositional gap arthroplasty with temporalis muscle graft and advancement genioplasty in a single operative session. Postoperatively, there was gradual and sustained improvement, with mouth opening reaching 40 mm at 1-year follow-up. The surgical site remained healthy, and significant aesthetic enhancement was achieved. Conclusion This case demonstrates that single-stage surgical correction of TMJ ankylosis and associated facial deformities, such as micrognathia, is not only feasible but also effective in improving both function and facial harmony. Early surgical intervention using a combined approach can prevent long-term complications such as obstructive sleep apnea, speech disturbances, and psychological distress, making it a valuable strategy in managing pediatric and adolescent TMJ ankylosis.