The accuracy of computer-assisted surgical planning in soft tissue prediction following orthognathic surgery.

BACKGROUND: The purpose of the present study was to evaluate the accuracy of a computer-assisted imaging system in predicting the soft tissue response following orthognathic surgery. METHODS: The study sample consisted of 11 adult patients with a mean age of 23.5 years. The preoperative and postoperative lateral cephalograms were obtained after orthodontic preparation and immediately before surgery and at least 1 year after surgery. The computer-generated soft tissue image and the actual surgical outcome were compared to evaluate the accuracy of the imaging system. RESULTS: In the sagittal plane, the tip of nose was the most accurate site and the largest difference was shown in the upper lip. The lower lip was noted to be the least accurate and the subnasale the most accurate region in the vertical plane. Predictions were found to be more accurate for the sagittal plane when compared with those for the vertical plane. CONCLUSIONS: Computer-assisted visual treatment objectives was proved to be satisfactory in predicting the soft tissue outcome following orthognathic surgery.

Distraction osteogenesis of basal mandibular bone for reconstruction of the alveolar ridge.

Alveolar distraction is being used increasingly for alveolar bone reconstruction in patients with severe mandibular defects. When there has been total loss of alveolar bone, distraction of the mandibular basal bone is necessary. Distraction osteogenesis is considerably more challenging in mandibular basal bone than in alveolar bone. The low level of the cut increases the technical difficulty and may result in a poor outcome. We describe three cases in which more than 10 mm of distraction of mandibular basal bone was required. Semirigid distraction devices were used to reconstruct the alveolar structures in each case.