Department of Oral and Maxillofacial Surgery, College of Dentistry, Yonsei University, Seoul, Korea.
J Am Dent Assoc. 2010 Mar;141(3):271-8. doi: 10.14219/jada.archive.2010.0160.
Paresthesia is a well-known complication of extraction of mandibular third molars (MTMs). The authors evaluated the relationship between paresthesia after MTM extraction and the cortical integrity of the inferior alveolar canal (IAC) by using computed tomography (CT).
The authors designed a retrospective cohort study involving participants considered, on the basis of panoramic imaging, to be at high risk of experiencing injury of the inferior alveolar nerve who subsequently underwent CT imaging and extraction of the MTMs. The primary predictor variable was the contact relationship between the IAC and the MTM as viewed on a CT image, classified into three groups: group 1, no contact; group 2, contact between the MTM and the intact IAC cortex; group 3, contact between the MTM and the interrupted IAC cortex. The secondary predictor variable was the number of CT image slices showing the cortical interruption around the MTM. The outcome variable was the presence or absence of postoperative paresthesia after MTM extraction.
The study sample comprised 179 participants who underwent MTM extraction (a total of 259 MTMs). Their mean age was 23.6 years, and 85 (47.5 percent) were male. The overall prevalence of paresthesia was 4.2 percent (11 of 259 teeth). The prevalence of paresthesia in group 3 (involving an interrupted IAC cortex) was 11.8 percent (10 of 85 cases), while for group 2 (involving an intact IAC cortex) and group 1 (involving no contact) it was 1.0 percent (1 of 98 cases) and 0.0 percent (no cases), respectively. The frequency of nerve damage increased with the number of CT image slices showing loss of cortical integrity (P=.043).
The results of this study indicate that loss of IAC cortical integrity is associated with an increased risk of experiencing paresthesia after MTM extraction.
感觉异常是下颌第三磨牙（MTM）拔除后常见的并发症。作者通过计算机断层扫描（CT）评估了 MTM 拔除后感觉异常与下牙槽神经管（IAC）皮质完整性之间的关系。
作者设计了一项回顾性队列研究，研究对象为根据全景成像认为有下牙槽神经损伤风险的患者，随后进行 CT 成像和 MTM 拔除。主要预测变量是 CT 图像上 IAC 与 MTM 之间的接触关系，分为三组：组 1，无接触；组 2，MTM 与完整 IAC 皮质接触；组 3，MTM 与中断的 IAC 皮质接触。次要预测变量是显示 MTM 周围皮质中断的 CT 图像切片数。结局变量是 MTM 拔除后是否存在术后感觉异常。
研究样本包括 179 名接受 MTM 拔除（共 259 个 MTM）的患者。他们的平均年龄为 23.6 岁，85 名（47.5%）为男性。感觉异常的总患病率为 4.2%（259 颗牙中有 11 颗）。组 3（涉及中断的 IAC 皮质）的感觉异常患病率为 11.8%（85 例中有 10 例），而组 2（涉及完整的 IAC 皮质）和组 1（无接触）的患病率分别为 1.0%（98 例中有 1 例）和 0.0%（无病例）。皮质完整性丧失的 CT 图像切片数越多，神经损伤的频率越高（P=.043）。
本研究结果表明，IAC 皮质完整性丧失与 MTM 拔除后感觉异常的风险增加相关。
