The chronologic prevalence of temporomandibular joint disorders associated with bilateral intraoral vertical ramus osteotomy.

Purpose: The purpose of this study was to evaluate the long-term stability of the improvement of symptoms associated with temporomandibular joint (TMJ) disorders after intraoral vertical ramus osteotomy for the treatment of mandibular prognathism.
Materials and Methods: A total of 217 patients who had undergone bilateral intraoral vertical ramus osteotomy (BIVRO) from 1998 to 2005 were evaluated preoperatively and 1, 3, 6, 12, 18, and 24 months postoperatively regarding mouth opening, clicking, and pain of the TMJ. A retrospective study was conducted based on the results.
Results: Remarkable improvement of TMJ symptoms after BIVRO was reliable. Preoperative TMJ sounds disappeared after BIVRO in 94.3% of joints, and most of the joints that were sound free preoperatively remained without TMJ sounds postoperatively (98.2%). However, 19 joints exhibited recurrence, and transient TMJ sounds were observed in 35 joints. Preoperative TMJ pain had improved in 97.9% of joints at 1 month postoperatively, and TMJ pain was not observed in any joints at 18 months after surgery. Joints that were pain free before surgery remained without pain, although there were 20 joints that exhibited transient TMJ pain. The mean mouth opening was 50.0 mm before surgery, which decreased to 34.92 mm at 1 month postoperatively. This was followed by an increase to 44.44 mm to 48.75 mm at 6 months postoperatively, and thereafter mouth opening showed 94.72% to 97.5% recovery compared with the preoperative state.
Conclusions: BIVRO can be used as a method of choice for relieving undesirable TMJ symptoms such as sound and pain, as well as for repositioning the condyle head to its physiologic position. Such favorable effects of BIVRO on the TMJ were not remarkably affected with time.