Computer-simulated bi-directional alveolar distraction osteogenesis.

OBJECTIVES: Computer-based surgical planning allows surgeons to evaluate bone morphology in three dimensions and to perform accurate virtual surgery preoperatively. This study was performed to evaluate the feasibility of using preoperative surgical simulation to enhance the clinical outcome in patients undergoing bi-directional alveolar distraction osteogenesis.

MATERIAL AND METHODS: Nine patients (mean age, 49 years; range, 20-61 years) with maxillary segmental alveolar defects following post-traumatic atrophy or disuse atrophy after periodontal tooth loss were enrolled in the study. All patients were scheduled for implant placement. Three-dimensional (3-D) morphological evaluation and virtual bi-directional distraction were performed with SimPlant CMF/OMS surgical simulation software (Materialise). In addition, use of an extraosseous bi-directional distraction device (V2-Alveolar Distraction System; Medartis AG) was evaluated during the 3-D alveolar regeneration simulation and resulting augmentation.

RESULTS: Alveolar height regeneration and labial-buccal augmentation were planned preoperatively using surgical simulation software. New bone formation with sufficient vertical augmentation of 5.8 mm was observed. As we encountered strong palatal inclination, the angulation required for labial-buccal augmentation during active distraction was the maximum angulation of 40 degrees , even greater than that required in the preoperative simulation of 23.9 degrees . Furthermore, the labial-buccal augmented angulation was gradually decreased to 11.2 degrees at the time of implant placement. In all cases, implantation was successful at the well-augmented sites, with sufficient primary stability after a 3-month consolidation period.

CONCLUSIONS: Preoperative 3-D simulation is a potentially valuable tool for treatment of the morphologically complicated oral-maxillofacial region. More realistic surgical simulations are anticipated with ongoing effort to collect and integrate clinical data into next-generation software.