UCSF

Introduction: Cone beam computed tomography (CBCT) technology has many known benefits in diagnosis and treatment planning. One area in early development is the use of CBCT in virtual orthognathic surgical simulation. The purpose of this study was to evaluate the accuracy of this technique in single jaw surgery performed by a single surgeon using a commercially available software package, InVivoDental v5.1 (Anatomage, San Jose, CA USA).

Methods and Materials: Presurgical CBCT scans of 19 patients who had undergone single jaw orthognathic surgery (9 maxillary LeFort I; 10 mandibular BSSO) were segmented, retrospectively, to create 3D models. Virtual surgery was performed using the surgical notes as a guide. The post-surgery scan and the pre-surgery scan were superimposed on the anterior cranial base to measure the differences between the simulation and the actual surgical outcomes.

Results: Mean linear differences were found to be 0.51 mm horizontally, 1.07 mm anteroposteriorly, and 1.20 mm vertically. Mean rotational differences were found to be 1.41° around the z axis (yaw), 0.64° around the y axis (roll), and 1.96° around the x axis (pitch).

Conclusions: Virtual simulation of orthognathic surgery using Anatomage InVivo software closely approximates the final outcome. This protocol can be used as a tool for surgical planning and splint fabrication with the addition of improved occlusal morphology from another source.