Accuracy of Virtual Surgical Planning in Treatment of Temporomandibular Joint Ankylosis Using Distraction Osteogenesis: Comparison of Planned and Actual Results.

PURPOSE: This study evaluated the accuracy of virtual surgical planning and 3-dimensional (3D) printed templates to guide osteotomy and distraction osteogenesis (DO) in the treatment of temporomandibular joint (TMJ) ankylosis and secondary mandibular deformity.

PATIENTS AND METHODS: Seven consecutive patients diagnosed with TMJ ankylosis and mandibular deformities were included. A composite skull model was obtained with data from spiral computed tomography (CT) and laser scanning of the dental arch. A virtual surgical simulation was performed using Dolphin Imaging 11.7 Premium (Dolphin Imaging and Management Solutions, Chatsworth, CA). Then, the virtual plan was transferred to the operation using 2 surgical templates. These templates were designed by 3D printing using data from the virtual surgical simulation for guiding the osteotomy and the DO, respectively. The preoperative measurement and differences between the actual mandibular position and the virtual plan were analyzed.

RESULTS: Postoperative radiographs, CT images, and quantitative analysis showed a clinically acceptable precision for the position of the mandible. The mean length of the mandible and the vertical height of the DO were 79.1 and 14.9 mm, respectively. With the 3D superimposition and linear measurement, the mean difference between the virtual plan and the actual results ranged from 0.64 ± 0.20 to 1.90 ± 0.85 mm. All patients obtained satisfactory changes in the facial profile and marked improvement in postoperative pharyngeal airway space and mouth opening.

CONCLUSION: The results of this study showed that virtual surgical planning and 3D printed guiding templates facilitated treatment planning, an accurate osteotomy, repositioning of bony segments, and contouring of the mandibular border in the treatment of TMJ ankylosis and secondary mandibular deformity.