Three-dimensional analysis of hard and soft tissue changes in patients with facial asymmetry undergoing 2-jaw surgery

Objective. We studied 3-dimensionally how hard and soft tissues of patients with facial asymmetry were changed by 2-jaw surgery. Study design. Nine patients diagnosed with mandibular prognathism and facial asymmetry who underwent 2-jaw surgery were enrolled. Three-dimensional (3-D) computed tomographic images taken before and after surgery were superimposed by 3-D imaging software. Linear and angular measurements of hard and soft tissues were performed and compared before and after surgery. Results. Along with improved roll rotations of the hard and soft tissues of the facial structures by surgery, both hard and soft tissue mentons were moved toward the nonshifted side. Only the hard tissue mentons, however, were important for improving the roll rotation of the mandible. Variations in the wing of the nose and lip were significant for shaping the maxilla. Conclusions. The 3-D analysis in this study enabled us to understand hard and soft tissues quantitatively, thereby providing helpful information for treatment planning.