顎関節症を伴う顎変形症患者に対する下顎枝垂直骨切り術(IVRO)の経験

The purpose of this study was to evaluate the clinical efficacy and changes of magnetic resonance (MR) imaging of temporomandibular joint (TMJ) by intraoral vertical ramus osteotomoy (IVRO). The subjects were ten patients with mandibular prognathism associated with TMJ clicking and dysfunction.Ten patients were treated with IVRO and followed-up for 226 days on average. Signs and symptoms and MR imaging of TMJ were evaluated in pre- and postoperative phases. Prior to IVRO, all patients had been treated nonsurgically for their TMJ dysfunction, and most of the patients relieved pain, but not joint clicking. Preoperative orthodontic treatment was performed for about 13 months.Surgical correction of mandibular prognathism by IVRO was successfully done without any episode of relapse, and clicking sound disappeared in all patients after surgery. There was neither associated pain nor dysfunction in all TMJs. In the MR imagings, postoperative improvement of preoperative abnormal disc configuration was found in four of eight TMJs, nine joints disclosed appropriate condylar sag, and normal disc-condyle coordination was restored in seven of ten joints. Interestingly, despite of no obvious imaging changes in the remaining subjects, clinical improvement was confirmed.These results suggested that IVRO may be a suitable surgery for a jaw deformity patient with concomitant TMJ clicking and dysfucntion.