Neurosensory deficit following mandibular sagittal split osteotomy: A comparative study between positional screws and miniplates fixation

This retrospective study compared the incidence of long-term inferior alveolar nerve injury for positional screws and miniplate fixation of bilateral sagittal split osteotomies carried out in 2 hospitals in Scotland. The study involved a mixture of mandibular setback and advancement surgery. The outcome of neurosensory deficit (NSD) was solely based on subjective assessment by the surgeons and patients' reported alteration in sensation. Numbness, tingling and any alterations in sensation beyond 6 months were considered long-term inferior alveolar nerve injury. This study was conducted on 28 sagittal split osteotomies (group 1) which were fixed with three upper border fixation screws and 36 sagittal split osteotomies (group 2) which were fixed with upper border sliding plate. The reported and documented neurosensory deficits were analysed. The difference in the number of cases of long-term inferior alveolar nerve injury between the 2 methods was 10.3%; the 95% confidence interval for the difference was [-2.94 to 23.5], p = 0.1612. Upper border plate was associated with more long-term NSD but there is insufficient evidence to prove that one method was more superior to the other. The need for a prospective randomized trial was highlighted.