Abstract: PURPOSE: To investigate the clinical value of modified digital guide plate technique in mandibular segmental resection and fibular flap reconstruction. METHODS: Sixteen patients were randomly divided into conventional guide plate technology group and improved digital guide plate group, who underwent mandibular segmental resection and vascularized fibular myocutaneous flap repair in the Affiliated Stomatological Hospital of Nanjing Medical University and Fuyang People's Hospital, from January 2016 to January 2020, eight cases in each group. The lesions of the mandible were all benign. Patients in the conventional guide technology group received routine examination before operation, and conventional guide designed the operation plan. Patients in the improved digital guide group underwent cone-beam CT (CBCT) of mandible and CTA of both lower limbs before operation. The data were imported into the digital guide software to simulate the operation process, and reconstructed 3D model was printed to make intraoperative guide for accurate positioning. Patients in both groups were reexamined with CBCT 2 weeks after operation, the condylar position change and mandible morphological change were selected as the reference. Through comparative analysis of preoperative and postoperative CT, the condylar position change, the mandible morphological change, mouth opening degree and opening type were analysed, and the operation effect of the two groups was compared. Before denture restoration, the patient satisfaction questionnaire was used to evaluate the masticatory function, speech function and facial appearance 3 months after operation. SPSS 25.0 software package was analyzed for different types of data by Student's t test and Wilcoxon Rank-Sum test. RESULTS: The two groups of patients were successfully operated. The condylar position change and mandible morphological change of the improved digital guide group were significantly less than that of the conventional guide group. The satisfaction degree of masticatory function and facial appearance in the improved digital guide group was significantly higher than that of the conventional guide group. There was no significant difference in the satisfaction of speech function between the two groups of patients. CONCLUSIONS: Improved digital guide plate technique has high clinical value in use of vascularized fibular myocutaneous flap to accurately repair the mandibular defects, which simplifies the operation process, reduces postoperative complications, and improves the accuracy of mandibular reconstruction.

Key words: Digital guide technology, Surgical guide plate, Mandibular defect, Fibular myocutaneous flap