Outcome of mandibular symphyseal distraction osteogenesis with bone-borne devices

Mandibular symphyseal distraction osteogenesis (DO) is an alternative to the orthodontic treatment to resolve mandibular anterior width deficiencies or dental crowding. Different types of devices (tooth-borne, bone-borne, and hybrid device) have been used until now. The aim of this clinical study was to report our results with bone-borne device and compare them with previous studies' data to improve our symphyseal distraction protocol and future results.

Fourteen patients were treated with symphyseal DO during a 10-year period. Two types of bone-borne distractors have been used. We evaluated morbidity and stability in the short- and long-term (from 12 to 24 months) follow-up, with clinical and radiological examinations.

Appropriate symmetrical distraction of both basal and alveolar bone was obtained for all the patients, but correction of the discrepancy failed in 1 case. Mucosa irritation was the main problem. None of the patients presented with local infection. One temporomandibular joint dysfunction occurred during the distraction period, and 1 patient with preoperative temporomandibular joint dysfunction had his symptoms resolved in the long-term follow-up. In 1 case, a root exposure occurred during osteotomy, resulting in an osteogenesis delay.

Considering the previous data of the literature and our clinical experience, mandibular symphyseal distraction is a safe alternative to orthodontic and previous surgical treatments, with low morbidity and stable long-term results. Bone-borne device is expected to assert stable results in the long term but with higher morbidity, compared with tooth-borne device. Both surgical techniques and devices have to improve, to assess the superiority of mandibular symphyseal DO to incisor-crowding treatment.