Accuracy of 3D-printed surgical guides compared with freehand technique for temporary anchorage device placement in the mandibular buccal shelf

Objective This in vitro study evaluated the accuracy of 3D-printed surgical guides for the placement of temporary anchorage devices (TADs) in the mandibular buccal shelf. Methods Fifty CBCT scans from the Dubai Dental Hospital database were used to create 100 3D-printed mandibular models. A total of 100 TADs (BENEfit “R” screw, 11 mm length, 2 mm diameter) were inserted in the buccal shelf region between the first and second molars. Each mandible was duplicated to form two groups: (1) a guided group, where TADs were placed using a custom-designed surgical guide, and a (2) manual group, where placement was performed freehand. Results The guided group showed significantly higher TAD placement accuracy than the manual group, with improved parallelism to roots, closer proximity to the buccal cortical bone, greater distance from the lingual cortical bone and root apices, more upright angulation, and increased safety from the inferior alveolar nerve ( p < 0.05). Placement success was 98% vs. 70% for guided and manual groups, respectively ( p < 0.001). Bone measurements showed greater width at the second molar and greater length at the first molar. Correlation analyses indicated that TAD angulation and proximity to cortical bone, root apices, and the inferior alveolar nerve were positively associated with local bone width, particularly at the second molar region ( p < 0.05). Conclusion The use of 3D-printed surgical guides significantly enhanced the accuracy, safety, and clinical reliability of TAD placement in the mandibular buccal shelf, offering a valuable adjunct to orthodontic practice.