Distraction osteogenesis for management of obstructive sleep apnea secondary to TMJ ankylosis
A 12-years-old female patient who had been operated for left TMJ ankylosis six months back, reported with the primary complaint of unaesthetic small chin. On further evaluation, patient revealed excessive day time somnolence, obnoxious snoring, disturbed sleep, dullness throughout the day and inability to concentrate. On clinical examination patient had short-neck, small chin-throat angle, fullness of the cheek on the left-side, flatness of the cheek on the right side, chin deviated to left side, mouth opening of 35 mm and prominent antegonial notch on the left side []. Orthopentomogram revealed evidences of surgery in left TMJ region (arthroplasty). Lateral cephalogram showed a decreased pharyngeal space [].\nBased on history, clinical examination, lateral cephalogram, and polysomnography, a diagnosis of obstructive sleep apnea due to reduced upper airway space secondary to left TMJ ankylosis was made. The treatment plan selected was distraction osteogenesis to advance the mandible by 11 mm that would increase the upper airway space and at the same time correct the asymmetry. The procedure was performed under general anaesthesia. An intraoral distractor was fixed in the left angle region []. Following a latency period of 5 days, the distraction device was activated at the rate of 1 mm/day till the desired lengthe was achieved, that is 11 mm. After 2 months of consolidation period the distractor was removed under local anaesthesia. A thorough postoperative clinical and lateral cephalometric examination were done in addition to polysomnography. Lateral cephalogram showed an increase in the pharyngeal airway shadow []. The polysomnogram showed an improvement in the respiratory distress index of 5 (presurgery was 51) and a mean oxygen saturation of 98% (presurgery was 84%). Two years after the surgery, the patient had stable clinical results. The patient does not suffer from snoring, day time somnolence or fatigue.