Distraction osteogenesis in the management of mandibular hypoplasia secondary to temporomandibular joint ankylosis. Long term follow up

A systematic review on the outcome of distraction osteogenesis in TMJ ankylosis

“…However, they have reported no significant difference between prearthoplasty and simultaneous distraction technique in terms of airway improvement after distraction in TMJ ankylosis cases. Hasan et al 41 on 20 patients of ankylosis with at least 7 years of follow-up also reported a significant increase of airway width similar to other studies. 20,26,27,31,35,50…”

“…Post arthroplasty DO [36][37][38][39][40][41] : Proponents of postarthroplastic DO believe that the chief complaint of the TMJa patients i.e. inability to open their mouths, should be addressed first.…”

“…A comparison of Prearthroplasty and simultaneous distraction showed that although prearthroplasty DO provides better control of the distracting segment, but unlike simultaneous distraction, it bears a disadvantage that the final mandibular position cannot be predicted as the final mandibular position tends to change due to muscle pull after the release of ankylosis. 26,30,34,37,41 An occlusal cant which exceeds 3 in frontal plane is clinically significant. In cases where delay in treatment leads to significant maxillary hypoplasia, mandibular distraction can be coupled with simultaneous maxillary distraction by Lefort 1 osteotomy and fixation at the contralateral zygomaticomaxillary buttress.…”

“…Ideally, the distraction vectors must lie parallel to the occlusal plane to prevent open bite from being produced during elongation. 23,41,62 This holds true especially for anteroposterior distraction after the growth has ceased. In the growing adolescents, lateral open bite is of limited concern because of the maxillary dentoalveolar compensation with ongoing growth.…”

“…DO fails to resolve the retruded chin completely. 38,41,69,71,72 The procedure of DO is less invasive but is more technique sensitive as incorrect vector planning is not forgiving and cannot be modulated. It's a long treatment with multiple hospital visits.…”