Purpose: This preliminary study was performed to clarify the usefulness of intraoral verticosagittal ramus osteotomy (IVSRO) in patients with temporomandibular joint (TMJ) disorders.
Patients and methods: We examined 34 sides in 19 consecutive patients with dentofacial deformities with TMJ dysfunction undergoing IVSRO. Preoperatively, 15 patients had TMJ sounds bilaterally and 4 had sounds unilaterally. Five sides in 3 patients had pain in the TMJ, and 4 sides in 3 patients had masticatory muscle pain. The TMJ symptoms, including TMJ sounds, pain in the TMJ, and masticatory muscle pain in each patient, were assessed clinically before and approximately 12 months after IVSRO. Magnetic resonance imaging was also performed to determine joint status, including determination of the positions of the condyle and disc.
Results: The symptoms of the TMJ after 12 months of orthodontic treatment showed marked improvements, with the disappearance of the TMJ sounds in 94% of the sides examined. Pain in the TMJ improved in 4 of 5 sides, and pain of the masticatory muscle improved in 3 of 4 sides. With regard to the relative positions of the condyle and disc on magnetic resonance imaging, 6 of 8 joints and 5 of 7 joints showed improvement in anterior disc displacement with and without reduction, respectively. The direction and mean amount of movement in the distal segment were 8 mm in setback, 4 mm in advance, and 5 mm counterclockwise.
Conclusion: IVSRO is potentially as useful for the treatment of TMJ disorders in orthognathic surgery patients as is intraoral vertical ramus osteotomy, and IVSRO can be used selectively in cases in which intraoral vertical ramus osteotomy is contraindicated.