Changes in soft tissue profile after sagittal split ramus osteotomy and retropositioning of the mandible

Purpose: The prediction of profile changes as a result of orthognathic surgery remains a problem during preoperative planning because of the different relative movements of the hard and soft tissues. This study analyzed the changes in soft tissue profile after sagittal split ramus osteotomy and mandibular setback. Patients and Methods: Soft tissue changes relative to hard tissue references were recorded by means of computer-supported measurements of preoperative and postoperative standardized lateral skull radiographs of 60 Class III patients. Results: An average backward transposition of the osseous pogonion of 7.1 mm was recorded. Relative to movements of this reference point in the sagittal plane, the soft tissue pogonion moved 83.9%, the soft tissue menton moved 98.9%, the labrale superior moved 32.0%, the stomion moved 45.2%, and the labrale inferior moved 79.6%. The same measurements: were performed in the vertical plane, and changes in soft tissue references were analyzed. There was a marked difference in soft tissue changes after mandibular retropositioning when compared with results after mandibular advancement reported in the literature. Conclusion: It was concluded that it is of great importance to consider both the direction and the surgical method when predicting profile changes in the vertical as well as sagittal plane after orthognathic surgery.