[Design and application of three-dimensional printing guide plate for oral and maxillofacial surgery]

Objective: To explore the application of three-dimensional (3D) printing technology in oral and maxillofacial surgery, so as to optimize and standardize its design and application. Methods: From January 2010 to December 2020, 40 cases of mandibular tumor surgery (20 cases of conventional group and 20 cases of guide plate group), 20 cases of temporomandibular joint replacement surgery (10 cases of conventional group and 10 cases of guide plate group), 20 cases of malocclusion surgery (10 cases of conventional group and 10 cases of guide plate group), 20 cases of radioactive particle implantation surgery (10 cases of CT guided group and 10 cases of guide plate group) were analyzed. All patients in the guide plate group were scanned with spiral CT, and the 3D models of the jaw and the donor bone area were reconstruction. According to the purpose of surgical guide, the design and clinical application of osteotomy guide, in place forming guide and puncture positioning guide were analyzed respectively. The design time of guide plate, the performance and printing time of guide material, the sterilization method of guide and its influence on accuracy, and the influence of guide application on operation time and accuracy were analyzed. Results: The design time of orthognathic guide plate was (2.9±1.8) d, and the design time of mandibular transplantation guide plate was (2.8±1.8) d, that of the temporomandibular joint replacement guide plate and the puncture guide plate was (2.2±0.3) and (0.9±0.3) d. The average printing time of the 40 maxilla model was (11.1±1.6) h, and that of the 40 mandible models was (2.6±0.4) h. The average printing time of the 40 sets of osteotomy and positioning guide plate was (2.5±0.8) h, and that of the 10 puncture positioning guide plate (1.1±0.4) h. The operation time of the conventional group was (6.99±1.10) and (6.02±0.55) h. In the CT guided group, the operation time was (1.91±0.55) h and (0.89±0.15). The operation time of mandible tumor operation and radioactive particle implantation in the guide plate group was less than that in the control group (P<0.05), and there was no significant difference in the operation time of orthognathic surgery and joint replacement between the two groups (P>0.05). The displacement distance of the mark points in the TMJ replacement and mandibular tumor operation guide group was less than that in the control group (P<0.05), and the error of the guide plate in orthognathic operation and particle implantation operation was basically less than 1 mm. Conclusions: The application of the surgical guide plate made by 3D printing technology helps to complete the operation more safely, accurately and quickly, But its design, manufacture and disinfection still need to be further standardized and improved.