Stability following combined maxillary and mandibular osteotomies treated with rigid internal fixation

Skeletal stability was examined in 16 patients following combined maxillary and mandibular osteotomies using rigid internal fixation. Postoperative changes (T2 to T3) were generally less than 1.0 mm for linear measurements and less than 2.0 degrees for angular measurements. The removal of maxillomandibular fixation (MMF) splints accounted for 85% to 95% of the counterclockwise rotation in the proximal and distal mandibular segments from T2 to T3. Maxillary inferior repositioning and large mandibular advancements exhibited the greatest tendency for relapse; however, the changes were less than with comparable procedures using nonrigid methods for stabilization. Except for large mandibular advancements, relapse was essentially unrelated to the magnitude of the surgical repositioning. Although the use of skeletal, maxillomandibular, and transosseous wire fixation have traditionally provided satisfactory clinical results, the use of rigid internal fixation in combined osteotomy procedures provides better stabilization of dentosseous segments when compared with these nonrigid methods, and may be particularly indicated in complex surgical procedures.