The accuracy of video imaging prediction in soft tissue outcome after bimaxillary orthognathic surgery

The purpose of the present study was to evaluate the accuracy of the outcome in soft tissue prediction through use of a computer imaging system after bimaxillary orthognathic surgery.

The study sample consisted of 30 adults who had undergone orthognathic surgery that included the Wassmund and Köle procedures and optional genioplasty to correct bimaxillary protrusion. All the patients had lateral cephalometric radiographs and profile photographs taken within 6 months before surgery and at least 6 months after surgery. The computer-generated soft tissue image and the actual postsurgical profile were compared. The accuracy of this computer-generated profile image was evaluated.

The results indicated that the nasal tip, soft tissue A point, and upper lip presented the least predicted errors in sagittal plane. While the nasal tip presented higher reliability. Lower lip prediction was found to be the least accurate region and it tended to be located anterior to the actual position. In the vertical plane, most of the predictions revealed higher accuracy than those in the sagittal plane. There were no statistically significant differences between the predictions of the groups with and those without genioplasty.

Computer-generated image prediction was suitable for patient education and communication. However, efforts are still needed to improve the accuracy and reliability of the prediction program and to include the consideration of changes in soft tissue tension and muscle strain. The accuracy of this system in soft tissue prediction should be carefully interpreted.