Mandibular range of motion with rigid/nonrigid fixation.

Decreased mandibular range of motion that followed orthognathic surgery and that was treated by wire osteosynthesis and 6 weeks of maxillomandibular fixation (MMF) has been previously documented. The present study evaluated maximum interincisal opening (MIO) in 49 subjects undergoing a bilateral sagittal ramus osteotomy (BSRO) with advancement or a BSRO with advancement and a concomitant LeFort I maxillary osteotomy with the patients having either rigid or nonrigid fixation. The group with rigid fixation had early function and mild physiotherapy. The nonrigid group had wire osteosynthesis, MMF that was maintained for 6 weeks, and no postoperative physiotherapy. Patients who underwent a BSRO with rigid fixation experienced a 3.5 mm decrease in MIO (6.9%). Those who had a BSRO and a LeFort I osteotomy with rigid fixation had a 3.3 mm decrease in MIO (6.6%). In contrast, nonrigidly fixed BSRO subjects had a 16.8 mm decrease (29.6%), while those who underwent a combined BSRO and LeFort I osteotomy had a 13.9 mm decrease (26.1%). This study showed that rigid fixation combined with early function and mild physiotherapy resulted in improved MIO postoperatively, as compared to the MIO in a group in which these treatments were not used.