Surgical restoration of maxillofacial defects by transport disc distraction osteogenesis : engineering aspects

• Main Author: Boonzaaier, James Angus
• Other Authors: Vicatos, George
• Format: Dissertation
• Language: English
• Published: University of Cape Town 2014
• Subjects: Mechanical Engineering
• Online Access: http://hdl.handle.net/11427/5561

Includes abstract. === Includes bibliographical references. === Transport disc distraction osteogenesis (TDDO) harnesses the natural healing mechanisms of bone to regenerate, and thus repairs, bone defects. Presently, no system is available for applying TDDO to the maxillary anatomy; specifically anterior-to-posterior distraction on a three-dimensional curvilinear vector. The objective of this study was to devise a system to enable repair of the defective maxilla. The mechanical and ergonomic requirements of treatment by TDDO were investigated in the literature and through consultation with experts in the medical and bio-medical engineering fields. These requirements were distilled into a definitive Product Requirement Specification. Three iterative versions of the device were manufactured and tested. After satisfying the functional requirements in bench-tests, each version of the device was evaluated clinically. The operational performance of each device directed refinement of subsequent versions, directing major improvements to ease-of-use and comfort. The project culminated in a fully-functional maxillary TDDO device that addresses the requirements of both surgeon and patient. Proven in practice, the prototype can be easily and accurately customised by the surgeon to suit a wide range of defective maxillofacial geometries. The current version of the device performed successfully in bench-testing, confirming the strength of critical features and demonstrating the presence of adequate safety factors. The current version of the device has been implemented in two clinical cases where it successfully facilitated the repair of substantialdefects of the maxillary alveolus and hard palate. In total, four patients with large maxillary defects were treated with successful outcomes using devices developed in this project. One case has reached completion, with structural restoration of the maxillary alveolus and hard palate, and supporting permanent implanted dentition. Three ongoing cases are awaiting consolidation of the bone regenerate before final dental rehabilitation can commence.