An average three-dimensional virtual human skull for a template-assisted maxillofacial surgery

Introduction: Although many advances have been made in three-dimensional virtual planning in maxillofacial surgery, facial harmony is still difficult to achieve and is heavily dependent on the surgeon's experience. The aim of the study is to present a method to build up an average three-dimensional virtual human skull to be used as a reference template for bone repositioning and reconstruction during maxillofacial surgical interventions. Methods: A total of 20 patients (10 females and 10 males) were selected for the optimal outcome after orthognathic surgery. Postoperative cone-beam computed tomography scans were collected and processed in order to obtain three-dimensional digital models of each skull. For male and female subgroups, the three-dimensional skull models were registered and an average three-dimensional virtual skull model was computed. Deviation color maps were calculated to show differences between each postoperative skull model in the population and the obtained average three-dimensional skull. A clinical use case of genioplasty treatment assisted by the provided average three-dimensional skull template was presented. Results: The overall mean deviation from the average three-dimensional skull model was 1.3 +/- 0.6 and 1.6 +/- 0.5 mm in male and female subgroups, respectively. For both groups, the greatest deviations were at the area of the mandible, while almost no deviation was found at the zygomatic and orbital areas. In the presented use case, the female average three-dimensional skull model was effectively used for guiding surgical planning. Conclusion: The presented method of obtaining an average three-dimensional virtual human skull may offer the interesting perspective of performing an innovative template-assisted maxillofacial surgery.