Integration of a maxillary model into facial surface stereophotogrammetry

Abstract

Three-dimensional (3D) integration of a maxillary model into a facial model has only been possible by a complex procedure using face bow transfer after taking impressions of certain maxillary and facial parts. In this study, we aimed to develop a method for integrating a scanned maxillary model into a scan-realized facial model. A total of 19 patients with the medical indication for cone-beam computed tomography (CBCT) and orthodontic treatment were included in this study. Facial and maxillary scans were also taken. The construction of the integrated surface model required 10 steps. This integration procedure was evaluated by taking ten 3D dentofacial linear segment measurements in the integrated scan and the CBCT. These results were analyzed using descriptive statistics. All measurements demonstrated good intra-individual reliability. We observed almost perfect congruence between integrated scan and CBCT in vertical distances, while the sagittal measurements revealed more, yet clinically acceptable, deviations possibly caused by different error sources in either of the two methods. This new method is suitable for generating 3D integrated surface-scan models which can be used for growth and therapy control studies in orthodontics and other disciplines in the dentofacial fields. Since this method does not require ionizing radiation, it is highly recommendable as an application for children and adolescent patients.