Based on the data from sagittal splitting osteotomies (Obwegeser-Dal Pont's method) for 19 cases and from body ostectomies for 14 cases, each method was evaluated by clinical assessment to elucidate the distinct characteristics of two methods. The clinical problems about body ostectomy will be especially discussed.
These two methods were almost the same in the amount of mandibular displacement, but the sagittal splitting osteotomy seemed to be preferable for the cases which had the transverse deviation deformity. Body ostectomy consisted of the two procedures of bone cut and bone resection Bone cut procedure included vertical cut and step cut, and bone resection procedure included Vshaped, rectangular and reverse V-shaped resection. Bone resection in the body ostectomy was not performed on the second nor third molars. This fact suggested that the body ostectomy method was indicated for the cases which had stable occlusion of the teeth on proximal segments. The assessment of postoperative disturbance of temporomandibular joint indicated a less incidence for the body ostectomy than the sagittal splitting osteotomy. Both methods had the same incidence in paresthesia of the lip and mental region 3 months postoperatively, however the body ostectomy showed a more delayed recovery from paresthesia. A less incidence of paresthesia was observed in the vertical cut procedure on the first premolar or in the step cut procedure. U1, L1, and Pog were found to change more anteriorly in the sagittal splitting osteotomy and more superiorly in the body ostectomy.
Consequently, the body ostectomy was demonstrated to have the following advantages: This method could reposition the mandible to the same extent as sagittal splitting osteotomy, disturbed temporomandibular joint in remarkably fewer cases, produced superior postoperative changes of the skeletal landmarks on the contrary to anterior changes with sagittal splitting osteotomy, and could avoid postoperative paresthesia with the proper bone cut procedure.
We concluded, therefore, that body ostectomy could present a satisfactory result in the case of stable occlusion on a proximal segment, no steep mandibular plane, lesser transverse deviation of mandible and no considerable amount of displacement.
