CAD/CAM splint and surgical navigation allows accurate maxillary segment positioning in Le Fort I osteotomy

Tatsuo Shirota; Sunao Shiogama; Yusuke Asama; Motohiro Tanaka; Yuji Kurihara; Hiroshi Ogura; Takaaki Kamatani

doi:10.1016/j.heliyon.2019.e02123

CAD/CAM splint and surgical navigation allows accurate maxillary segment positioning in Le Fort I osteotomy

Heliyon. 2019 Jul 22;5(7):e02123. doi: 10.1016/j.heliyon.2019.e02123. eCollection 2019 Jul.

Authors

Tatsuo Shirota¹, Sunao Shiogama¹, Yusuke Asama², Motohiro Tanaka¹, Yuji Kurihara¹, Hiroshi Ogura³, Takaaki Kamatani¹

Affiliations

¹ Department of Oral and Maxillofacial Surgery, School of Dentistry, Showa University, Tokyo, Japan.
² Department of Orthodontics, School of Dentistry, Showa University, Tokyo, Japan.
³ Department of Information Science, Faculty of Arts and Sciences at Fujiyoshida, Showa University, Fujiyoshida, Japan.

Abstract

Purpose: To evaluate the accuracy of the maxillary segment positioning method using a splint fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM) and surgical navigation in patients who required two-jaw surgery.

Methods: Subjects were 35 patients requiring two-jaw surgery. A 3-dimensional (3D) skull model was prepared using cone-beam computed tomography (CBCT) data and dentition model scan data. Two-jaw surgery was simulated using this model, and a splint for maxillary positioning was fabricated by CAD/CAM. Using coordinate transformation software, the coordinate axis of surgical simulation data was merged with the navigation system, and data were imported to the navigation system. The maxillary segment was placed using the CAD/CAM splint, and consistency of the maxillary segment position with that planned by simulation was confirmed using the navigation system. CBCT taken at 4 weeks postoperatively and the prediction image fabricated using surgical simulation were superimposed. Predicted movement distances (PMD) at 6 arbitrary measurement points and actual movement distance (AMD) in surgery were measured. Differences of 3D measurements between the surgical simulation and postoperative results were evaluated.

Results: No significant differences were seen between PMD and AMD at most measurement points on the X and Y axes. Although significant differences between PMD and AMD were seen on the Z axis, no difference was evident between linear distance on the estimated image and postoperative CBCT image at most measurement points in 3D space. Mean error at measurement points between the PMD and AMD ranged from 0.57 mm to 0.78 mm on the X axis, 0.64 mm-1.03 mm on the Y axis, and 0.84 mm-0.90 mm in the Z axis.

Conclusion: Position of the maxillary segment moved by the CAD/CAM splint in Le Fort I osteotomy was almost consistent with the position established by simulation using the navigation system, confirming clinical accuracy.

Keywords: CAD/CAM splint; Orthognathic surgery; Surgery; Surgical navigation; Surgical simulation.