Abstract： Objective In this paper,an automated method for mandibular osteotomy surgical planning based on the automatic i-dentification of mandibular landmark points is proposed within the context of facial skeletal contour surgery.Methods From September 2021 to September 2022,the Department of Plastic and Reconstructive Surgery at Shanghai Nineth People's Hospital,Shanghai JiaoTong University School of Medicine collected preoperative CT data from 34 patients with mandibular angle hypertrophy.Based on the automatic recognition of mandibular anatomical landmarks,an automatic planning method for mandibular angle osteotomy in facial bone contouring surgery was proposed.(1)Development of the automatic osteotomy algorithm:Hierarchical oriented bounding boxes(HOBB)were utilized to identify mandibular anatomical landmarks and formulate preoperative osteotomy plans.These plans were generated based on the identified anatomical features.(2)Analysis and comparison of software-designed osteotomy results:The 34 patients were divided into two groups:Group A,which received osteotomy plane designs from the algorithm,and Group B,which received manually designed osteotomy planes.The efficiency,safety,consistency of anatomical landmark identification,and symmetry of the osteotomies were analyzed.A small sample prospective single-arm study was also conducted.Results The time required to design preoperative osteotomy plans was(1.132±0.021)min for Group A and(28.247±1.181)min for Group B,with P<0.001.For the minimum distance from the osteotomy plane to the mandibular foramen,all patients in Group A had a distance≥5 mm,which meets the established safety threshold.In Group B,38.24%of the patients had a distance<5 mm,demonstrating the safety of the proposed method over manual osteotomy planning.Both groups exhibited consistency and symmetry in anatomical landmark identification and achieved high subjective aesthetic scores.Group A showed bilateral symmetry with higher subjective aesthetic scores.In the small sample prospective single-arm study,all patients were successfully treated,with high satis-faction rates reported by both the medical staff and patients.Conclusion The automatic osteotomy software,with high efficiency,safety,and aesthetics equivalent to those of manual design,can be utilized as an alternative method for manual osteotomy planning.