2005 Volume 17 Issue 3 Pages 224-231
The purpose of this study was to evaluate the morphological changes of the temporomandibular joint (TMJ) in patients with mandibular prognathism before and after surgical orthodontic treatment using magnetic resonance imaging (MRI).
A total of 26 patients (5 men, 21 women, mean age 22.9 years) who underwent sagittal split ramus osteotomy (SSRO) were examined. We evaluated the changes of disc position, disc morphology, and condylar morphology. Anterior disc displacement (ADD) was seen in 9 of 52 joints (17.3%) before treatment. There was no change in ADD after treatment. Disc deformity was seen in 9 of 52 joints (17.3%) before treatment. After treatment, disc deformity was worse in one joint. There was no significant difference of disc position or disc morphology between before and after treatment. Condylar bony change was seen in 2 of 52 joints (3.8%) before treatment. After treatment, the number of joints with condylar bony change increased from two to three (5.8%). There was no significant difference of condylar bony change between before and after treatment. The rate of ADD and joints with condylar bony change in patients with the deviation side of mandibular asymmetry was significantly higher than that in patients with mandibular symmetry. There was no significant difference of ADD and condylar bony change between before and after treatment. This study suggested that surgical orthodontic treatment with SSRO on patients with mandibular prognathism had a small effect on the TMJ.
