Registration for computer-navigated surgery in edentulous patients: A problem-based decision concept

Background: Surgical navigation is a commonly used tool in cranio-maxillofacial surgery. Registration is the key element for precision, and a number of studies have shown different techniques to be accurate. Nonetheless, uncertainty surrounds the special situation in edentulous patients and a practical approach to what can be a challenging problem. Materials and methods: Four registration strategies for the Brainlab VectorVision(2) system are presented for surgical navigation of edentulous patients: three landmark-based, point-to-point techniques and one surface-based matching strategy are evaluated. Results: The methods described differ in overall accuracy as well as in the region covered. In general, the more time-consuming and invasive the technique, the more precise it is. The non-invasive techniques are less precise, and they cover only small regions with sufficient accuracy. Conclusions: Taking into account which type of accuracy is clinically relevant and that the whole skull does not always need to be covered with the greatest possible accuracy, all the described techniques have their indications. The simpler and less invasive techniques can spare time, decrease costs, and harm patient. A decision tree is presented to the reader. (C) 2010 European Association for Cranio-Maxillo-Facial Surgery.