Factors affecting the stability of bilateral sagittal split osteotomy of a mandible.

Stability of bilateral sagittal split osteotomy (BSSO) is an important goal for every surgeon. In the article factors influencing stability of the surgery result are reviewed. Special emphasis is given to different types of fixation of bone fragments. Their advantages and disadvantages in clinical use are discussed. Relapse after BSSO is usually classified as early and long-term relapse. Early relapse is usually caused by movements at the osteotomy site or temporomandibular joint sag and should be called surgical displacement. Long term relapse happens due to the progressive temporomandibular joint condylar resorption, which causes a lost of condylar and mandibular ramus height. Four different types of fixation were described in orthognatic surgery: rigid intermaxillary fixation, osteosuture, osteosynthesis and fixation with biodegradable materials.