Kim Myung-Jin, Seo Jihee, Kim Do-Keun, Baek Seung-Hak
Department of Oral and Maxillofacial Surgery, School of Dentistry, Dental Research Institute, Seoul National University, Seoul, Republic of Korea.
Department of Orthodontics, School of Dentistry, Dental Research Institute, Seoul National University, Seoul, Republic of Korea.
Am J Orthod Dentofacial Orthop. 2017 Jan;151(1):186-200. doi: 10.1016/j.ajodo.2015.11.033.
Our objective was to report a patient treated with 3-dimensional virtual-surgery simulation-assisted asymmetric bilateral mandibular distraction osteogenesis.
A boy (age, 9.5 years) had mandibular hypoplasia and facial asymmetry, induced by bilateral condylar fractures at 4 years of age. The asymmetric bilateral mandibular distraction osteogenesis was planned to correct facial asymmetry and mandibular hypoplasia. The 3-dimensional virtual-surgery simulation results were 11 mm of horizontal distraction on the right side and 4.5 mm of horizontal and 18 mm of vertical distraction on the left side of the mandible. Bilateral ramus osteotomies were performed, and intraoral unidirectional distraction devices were inserted. After a 6-day latency period, distraction was performed at 1 mm per day, followed by a 5-month consolidation period. Transarch and interarch elastics and an acrylic plate were used during distraction and consolidation. Total treatment time was 30 months.
Satisfactory outcomes were obtained (achievement ratios between postconsolidation results and simulated results: gonial angle, 106% and 103.9%; mandibular body length, 94.2% and 89.9%; ramus height, 104.1% and 94.5% [values of the right and left sides, respectively]). The chin-point deviation and the transverse cant of the maxillary occlusal plane were significantly improved (10.1 mm to 3.3 mm; -6.8° to -4.4°). At 53 months of follow-up, the Class I molar relationship was well maintained. The transverse cant of the maxillary occlusal plane was slightly improved to -3.7° during pubertal growth.
Three-dimensional virtual-surgery simulation can help clinicians to determine the optimal vector and amount of distraction with high accuracy in complex cases requiring simultaneous correction of a hypoplastic mandible and facial asymmetry.
我们的目的是报告一例接受三维虚拟手术模拟辅助的不对称双侧下颌骨牵张成骨治疗的患者。
一名9.5岁男孩因4岁时双侧髁突骨折导致下颌骨发育不全和面部不对称。计划进行不对称双侧下颌骨牵张成骨以纠正面部不对称和下颌骨发育不全。三维虚拟手术模拟结果显示，下颌骨右侧水平牵张11毫米，左侧水平牵张4.5毫米、垂直牵张18毫米。进行双侧升支截骨术，并插入口内单向牵张装置。经过6天的延迟期后，每天以1毫米的速度进行牵张，随后是5个月的巩固期。在牵张和巩固期间使用牙弓间和颌间弹力牵引以及丙烯酸板。总治疗时间为30个月。
获得了满意的结果（巩固后结果与模拟结果之间的达成率：下颌角，分别为106%和103.9%；下颌体长，分别为94.2%和89.9%；升支高度，分别为104.1%和94.5%[分别为右侧和左侧的值]）。颏点偏斜和上颌咬合平面的横向倾斜明显改善（从10.1毫米改善至3.3毫米；从-6.8°改善至-4.4°）。在随访53个月时，Ⅰ类磨牙关系维持良好。在青春期生长期间，上颌咬合平面的横向倾斜略有改善至-3.7°。
在需要同时纠正发育不全的下颌骨和面部不对称的复杂病例中，三维虚拟手术模拟可以帮助临床医生高精度地确定最佳牵张向量和牵张量。
