Summary Objectives Mandibular advancement is a proven method in the management of obstructive sleep apnoea syndrome (OSAS) which may manifest as sleep disturbances with nocturnal desaturations during sleep (NDS). The purpose of this study is to evaluate the role of primary osteo-distraction prior to ankylosis release in pediatric patients, diagnosed with NDS secondary to temporomandibular joint (TMJ) ankylosis. Methods Three patients in the age group of 8–12 years diagnosed with OSAS secondary to TMJ ankylosis underwent primary osteo-distraction for mandibular advancement. They were evaluated pre- and post-operatively using radiographs, over night pulse oximetry, and subjective evaluation of their sleep patterns. Results All the three patients showed significant improvement in their saturation levels with a mean oxygen saturation of 94.66%. There was marked reduction in their snoring and sleep/awakening patterns. The mean advancement of the mandible in the three patients was 13.8 mm. Conclusion Primary mandibular distraction is an effective method of correction of nocturnal desaturations during sleep in patients with TMJ ankylosis.