Is inferior border osteotomy beneficial in bilateral sagittal split osteotomy? A retrospective clinical study

Abstract

Background To investigate the effect of lower border osteotomy on the lingual split pattern and inferior alveolar nerve (IAN) in bilateral sagittal split osteotomy (BSSO). Materials and Methods The study comprised 32 patients (64 operated sides) who underwent BSSO due to dentofacial abnormalities. In the mandible, 32 sides (the conventional group) received standard BSSO surgery, while 32 sides (the modified group) additionally received lower border osteotomy. The split difficulty of the mandible, the lingual split pattern, and the recovery status of the IAN were evaluated. Results Mandibular split difficulty showed a statistically significant difference favoring the modified group (p = 0.032). The mean numbness level of the modified group following surgery was lower than that of the conventional group (p = 0.019). Although there was no statistically significant difference between the two groups regarding lingual fracture pattern, the rate of type 1 fracture was higher in the modified group (p = 0.089). Conclusion The additional lower border osteotomy makes the split procedure easier. The modification resulted in an increased incidence of type 1 lingual fracture pattern. The neurosensory recovery capacity of the IAN in the postoperative period is higher in modified group.