Bilateral sagittal split osteotomies versus mandibular distraction osteogenesis: which is better?

Abstract

Background and Objectives: Bilateral sagittal split osteotomy (BSSO) and mandibular distraction ostoegenesis (MDO) have both been applied in the surgical treatment of Class II mandibular hypoplasia. For advancements between 6-10 mm, there has yet to be any comparison of which method is more stable. BSSO have also been associated with a high incidence of neurosensory disturbance of the inferior alveolar nerve (IAN). This randomised controlled trial aims to compare the stability and morbidities of both techniques for mandibular advancements between 6-10 mm.

Methods: 14 Class II mandibular hypoplasia patients requiring mandibular advancement of 6–10 mm were randomised into 2 groups for either BSSO or MDO. Serial lateral cephalographs were taken at postoperative periods 2 weeks (TBD1), 6 weeks (TBD2), 12 weeks (TBD3), 6 months (TBD4) and 12 months (TBD5). Skeletal stability using specific cephalometric landmarks was assessed at the respective postoperative periods. Objective neurosensory evaluation was performed and any postoperative complications recorded. The paired t test was used to analyse stability and neurosensory scores with statistical significance set at P < 0.05.

Results: There was no significant difference (P > 0.05) in horizontal skeletal stability between the two groups from TBD1-TBD5. Objective neurosensory evaluation showed no significant differences (P > 0.05) in objective scores from TBD1-TBD3 between the 2 groups. Postoperative complications included posterior open bite (BSSO = 1; MDO = 1), wound infection (BSSO = 2; MDO = 4) and condylar resorption (BSSO = 1; MDO = 1).

Conclusions: Skeletal stability and postoperative complications seem to be comparable between BSSO and MDO for advancements between 6–10 mm. Both groups reported elevated objective neurosensory scores in the early-postoperative period. A greater sample size is required to ascertain which technique is better.