基于解剖点识别的下颌角截骨术前设计算法的可行性研究

Feasibility study of a preoperative design algorithm for mandibular angle osteotomy based on anatomical landmark recognition

目的评价基于解剖点自动识别的方法辅助实施下颌角精确截骨术的有效性.方法自2021年9月至2022年9月,上海交通大学医学院附属第九人民医院整复外科采集34例下颌角肥大患者术前CT资料,以自动识别下颌骨标志点为基础,在面部骨骼轮廓手术中提出了一种基于自动识别下颌骨解剖标志点的下颌角截骨术的自动规划方法.(1)开发了自动截骨算法.使用分层定向包围盒(hierarchical oriented bounding boxes,HOBB)建立下颌骨解剖标志点,并制定术前截骨计划.根据这些特征点生成术前截骨计划.(2)对软件设计的截骨结果进行了分析和比较.34例患者分别接受了算法设计的截骨平面设计(A组)和手动截骨设计的截骨平面设计(B组).对两侧截骨的效率、安全性、解剖点标记的一致性和对称性进行了分析.并进行了一项小样本前瞻性单臂研究.结果A组和B组设计术前截骨方案的时间分别为(1.132±0.021)min和(28.247±1.181)min,P<0.001.对于截骨平面距离下颌神经孔的最小距离,A组患者均≥5 mm即设定的安全距离,B组38.24%的患者<5 mm,证明了本方法替代人工截骨规划的安全性.在一致性、对称性和主观美学评分上,两组具有一致性,A组左右两侧具有对称性,具有较高的主观美学评分.对于小样本前瞻性单臂研究,所有患者均得到成功治疗,且医患双方满意度较高.结论自动截骨软件具有高效、安全和美观的特点,可作为人工截骨规划的替代方法.

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.