Vertical lengthening of ascending mandibular ramus. Correction of open bite. Symmetric mandibular setback. Minor asymmetric mandibular setback. Periosteum is not the major source of the blood supply.
Medullary vessels are sufficient to maintain perfusion.
Biologic Considerations Osseous Anatomy Thickness of the medullary portion influences the ease of osseous sagittal split. 3rd molars should ideally be extracted 6-12 months prior to anticipated BSSO for bone healing. If rigid fixation is considered, the thickness of lateral and medial corteces become more important. Technique The buccal fat pad is identified and delineated. Leave enough mucosa for closure.