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The aim of this prospective study was to correlate the postoperative 3-dimensional facial changes in skeletal class III deformity with sagittal jaw movements in 84 patients who had been treated by one piece Le Fort I maxillary advancement only (n = 18), mandibular setback only (n = 38), or both procedures (n = 28). At the times of evaluation before and six months after operation all patients had fixed orthodontic appliances. Soft tissue changes were evaluated on optical 3-dimensional scans, while lateral cephalograms were superimposed to assess sagittal jaw movements. Three-dimensional surface facial scans were divided into 11 regions. We modelled soft tissue changes in each region by linear regression with maxillary (point A) and mandibular (point B) sagittal movements as predictors, and adjusted for sex, age, body mass index, type of operation, and interincisal angle. We found the highest values of regression coefficients (around 0.5) for the sagittal movements of the variables points A and B within the regions of the upper and lower lips. This meant that for each mm of maxillary advancement and mandibular setback, the soft tissue moved 0.5 mm. In the sides of the face the regression coefficients were between 0.1 and 0.3, as were those within regions indirectly affected by the operations. [ABSTRACT FROM AUTHOR]

The decision is not always straightforward as to which orthognathic procedure is best for a good aesthetic result; three-dimensional imaging has brought new insight into this topic. The aim of this prospective study was to verify objectively whether postoperative changes occur within those regions not directly affected by surgical movements of the underlying jaw bones. The study included 83 young adults with skeletal class III deformities. They were classified into three groups according to the type of surgery: bilateral sagittal split osteotomy set-back of the mandible (BSSO), Le Fort I advancement of the maxilla, or a combination of both. Pre- and postoperative optical scans were registered as regional best-fits on the areas of the foreheads and both orbits. The shell to shell differences were measured and the average distances between the observed regions were calculated. As expected, changes were greatest in the regions where the underlying bones had been moved, but regardless of the operation performed, changes were found over the whole face. Changes in the nose, cheek, and upper lip regions in the BSSO group and in the lower lip and chin region in the Le Fort I group confirmed the concept of the facial soft tissue mask acting as one unit. [ABSTRACT FROM AUTHOR]