Abstract
A 16-year-old female patient underwent mandibular lengthening by Backward Distraction Osteogenesis (BDO) for Angle Class II case with retrognathia. We experimented with facial and skeletal changes using cephalometry, and also analyzed the patient for possible changes of oral functions before and after treatment.
The results were as follows:
1) The mandibular lengthening showed effective results within five days, and the patient's profile and jaw relationship both improved after the treatment.
2) Relapse was not seen and the posttreatment conditions were stable after removing the lengthening device.
3) As for oral functions, maximum vertical opening increased and lateral movement resulted in a symme-try after BDO in the path of mandibular border movement. At the maximum velocity of opening and closing phases, a click point that had appeared clearly during the closing phase before the treatment, had disappeared after the treatment.
4) As for MRI findings, both discs were displaced anteriorly without reduction before the treatment, but the anterior displacement with reduction was observed after the treatment during the opening phase.
From these results, it was suggested that the BDO which was combined with SSRO and mandibular lengthening seemed to be a favorable technique to advance the mandible of an Angle Class II case with retrognathia.