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 surg ery remains a problem during preoperative planning because of the different relative movements of the hard and soft tissues. This study analyzed the c hanges in soft tissue profile after sagittal split ramus osteotomy and mand ibular setback. Patients and Methods: Soft tissue changes relative to hard tissue reference s were recorded by means of computer-supported measurements of preoperative and postoperative standardized lateral skull radiographs of 60 Class III p atients. Results: An average backward transposition of the osseous pogonion of 7.1 m m was recorded. Relative to movements of this reference point in the sagitt al plane, the soft tissue pogonion moved 83.9%, the soft tissue menton move d 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 retroposit ioning when compared with results after mandibular advancement reported in the literature. Conclusion: It was concluded that it is of great importance to consider bot h the direction and the surgical method when predicting profile changes in the vertical as well as sagittal plane after orthognathic surgery.