The effect of physical rehabilitation on mandibular function after ramus osteotomies.

The efficacy of a systematic regimen of rehabilitation of mandibular function after ramus osteotomy was investigated. Forty-eight patients who had had either sagittal split ramus osteotomy to advance the mandible or intraoral vertical ramus osteotomy to retract the mandible were studied; 24 patients received rehabilitation and 24 did not. Pre- and postsurgical maximal mandibular opening, lateral and protrusive mandibular movements, maximum bite force, muscle fatigability, and clinical evaluation of the temporomandibular joints were compared between the two groups. Patients who underwent an intraoral vertical ramus osteotomy did not show a significant decrease in any of the parameters measured whether or not rehabilitation was used. However, patients who underwent sagittal split ramus osteotomies without subsequent rehabilitation had significant decreases (P less than 0.05) in mean mandibular opening and bite force as well as increases (P less than 0.05) in muscular fatigability compared with patients who underwent rehabilitation. These findings indicate the need for routine preoperative evaluation of mandibular and temporomandibular joint function and postsurgical physical rehabilitation after ramus osteotomies.