Application of three-dimensional printing technology in osteotomy for chin width and prominent mandibular angle

Abstract

Objective To explore the applied value of computer-aided design and three-dimensional printing technology in osteotomy for chin width and prominent mandibular angle. Methods Sixteen patients with chin width and prominent mandibular angle were admitted to the Plastic Surgery Ward of the Second Affiliated Hospital of Zhengzhou University. All patients underwent preoperative computer-aided design, three-dimensional reconstruction of head and face, reconstruction of mandibular nerve canal, intelligent osteotomy line design of chin and mandible, simulation of chin and mandibular angle osteotomy, 3-D printing of surgical template to complete osteotomy, and internal fixation of chin osteotomy plate. The mandibular angle (Co-Go-Me), mandibular ramus height (Co-Go), mandibular body length (Go-Me), subfacial width (Go-Go’), chin nodule width (Ge-Ge’) and face height (N-Me) were measured preoperation, before surgical simulation and postoperation. Co-Go-Me, Co-Go/Go-Me, Go-Go’/N-Me and Ge-Ge’/N-Me were compared and analyzed in preoperation, before surgical simulation and postoperation. Results All the patients were satisfied with their facial shape. The mandible was almost symmetrical after operation. No complications such as nerve injury and infection occurred after operation, which fully met the preoperative design requirements. The mandibular angles in the left and right sides of patients before operation were significantly less than those after operation (t=2.890, 2.886, P 0.05). The average mandibular angles after operation were (123.9±3.0)°. Co-Go/Go-Me in the left and right sides of patients before operation was significantly higher than that after operation (t=3.607, 2.860, P 0.05). The ratio of the length of the left and right mandibular body to the height of the ascending ramus was close to 2: 1. Preoperative Go-Go’/N-Me was significantly higher than that post-operation (t=3.102, P 0.05). Preoperative Ge-Ge’/N-Me was significantly higher than that post-operation (t=3.010, P 0.05) . Conclusion The application of computer-aided design and three-dimensional printing technology in osteotomy for large chin and hypertrophic mandibular angle can significantly improve the accuracy of operation, reduce the difficulty of operation, improve the cosmetic effect, and reduce the occurrence of complications such as infection and injury of important nerves and blood vessels. Key words: Chin width; Prominent mandibular angle; Computer-aided design; Surgical template; Three-dimensional printing technology