Doucet Jean-Charles, Morrison Archibald D, Davis Benjamin R, Gregoire Curtis E, Goodday Reginald, Precious David S
Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Dalhousie University, Halifax, Nova Scotia, Canada.
J Oral Maxillofac Surg. 2012 Aug;70(8):1935-43. doi: 10.1016/j.joms.2011.08.018. Epub 2011 Dec 10.
The purpose of this study was to investigate prospectively the effects of the presence or absence of third molars during sagittal split osteotomies (SSOs) on the frequency of unfavorable fractures, degree of entrapment and manipulation of the inferior alveolar nerve (IAN), and procedural time.
The investigators designed and implemented a prospective cohort study and enrolled a sample composed of patients who underwent SSOs to correct mandibular deformities. The primary predictor variable was the status of the mandibular third molar at the time of SSO, and it was divided into 2 levels, present at the time of SSO (group I) or absent at the time of SSO (group II). The primary outcome variable was unfavorable splits. The secondary outcome variables were the degree of entrapment/manipulation of the IAN and the procedural time. Appropriate bivariate and multivariate statistics were computed, and the level of statistical significance was set at P < .05.
Six hundred seventy-seven SSOs were performed in 339 patients: group I consisted of 331 SSOs (mean age ± SD: 19.6 ± 7.4 yrs), and group II consisted of 346 SSOs (30.4 ± 12.1 yrs). The overall rate of unfavorable fractures was 3.1% (21 of 677), with frequencies of 2.4% (8 of 331) in group I, compared with 3.8% (13 of 346) in group II (P = .3). The rate of IAN entrapment in the proximal segment was significantly lower in group I (37.2%) than in group II (46.5%; P = .01). The degree of entrapment was also significantly more severe for group II (P < .001). Third molars increased procedural time by 1.7 minutes (P < .001).
The presence of third molars during SSOs is not associated with an increased frequency of unfavorable fractures. Concomitant third molar removal in SSOs also decreases proximal segment IAN entrapment but only slightly increases operating time.
本研究的目的是前瞻性地调查矢状劈开截骨术（SSO）过程中第三磨牙的有无对不良骨折发生率、下牙槽神经（IAN）的卡压和操作程度以及手术时间的影响。
研究者设计并实施了一项前瞻性队列研究，纳入了接受SSO以矫正下颌骨畸形的患者样本。主要预测变量是SSO时下颌第三磨牙的状态，分为两个水平，SSO时存在（I组）或SSO时不存在（II组）。主要结局变量是不良劈开。次要结局变量是IAN的卡压/操作程度和手术时间。计算了适当的双变量和多变量统计量，统计学显著性水平设定为P < .05。
对339例患者进行了677次SSO：I组包括331次SSO（平均年龄±标准差：19.6±7.4岁），II组包括346次SSO（30.4±12.1岁）。不良骨折的总体发生率为3.1%（677例中的21例），I组的发生率为2.4%（331例中的8例），而II组为3.8%（346例中的13例）（P = .3）。I组近端节段IAN卡压率（37.2%）显著低于II组（46.5%；P = .01）。II组的卡压程度也显著更严重（P < .001）。第三磨牙使手术时间增加了1.7分钟（P < .001）。
SSO过程中第三磨牙的存在与不良骨折发生率增加无关。在SSO中同时拔除第三磨牙也可降低近端节段IAN卡压，但仅略微增加手术时间。
