Evaluation of the treatment for micromandibular deformity by distraction osteogenesis with submerged intraoral device.

OBJECTIVE

To evaluate the results of distraction osteogenesis for correcting the micromandible with an intraoral device.

MATERIALS AND METHODS

Eight cases of micromandible resulting from temporomandibular joint (TMJ) ankylosis and first and second branchial arch syndrome received treatment by distraction osteogenesis. Subjects included 5 females and 3 males, ranging in age from 10 to 43 years (avg 20.25). Five micromandibles were associated with obvious mandibular asymmetry. An osteotomy was performed on bilateral mandibular bodies by intraoral approach. Elongation was started on the 5th or 6th day postoperation at a rate of 0.8 to 1 mm per day. The distractors were removed after a consolidation period from 71 to 139 days.

RESULTS

The distractions were fulfilled with a range of 8.5 to 24.4 mm. Pain appeared in osteotomy region when the 1 mm distraction was carried out once a day and disappeared when it was divided into twice a day. Mandibular lengthening was successful. Micromandible and facial asymmetries were corrected satisfactorily. The follow-up period ranged from a minimum of 1 month to a maximum of 10 months. There was no recurrence. One case of soft tissue infection and one case of lower lip numbness were reported. There were no cases of infection or other disturbance of wound healing or pseudarthrosis.

CONCLUSIONS

Because of its advantage in little injury, avoiding bone grafting, and few complications, intraoral distraction osteogenesis is a valuable approach to correct mandibular agenesis. However, in the management of mandibular deformities, distraction osteogenesis achieves better results when combined with other orthognathic operations. How to control the direction of distraction is a problem that needs further study.