Lin Ming-Hung, Mau Lian-Ping, Cochran David L, Shieh Yi-Shing, Huang Po-Hsien, Huang Ren-Yeong
Department of Periodontology, School of Dentistry, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan.
Department of Periodontics, Chi Mei Medical Center, Tainan, Taiwan.
J Dent. 2014 Mar;42(3):263-70. doi: 10.1016/j.jdent.2013.12.014. Epub 2014 Jan 3.
To investigate the prevalence and morphological parameters of lingual concavity, and whether these factors are related to a higher risk of inferior alveolar nerve (IAN) injury when performing an immediate implant surgery in posterior mandible region.
The CBCT images from 237 subjects (1008 teeth) were analysed the shape of the mandibles (C, P, U type), dimensional parameters of lingual concavity (angle, height, depth), and its relation to inferior alveolar canal (IAC) (A, B, C zone), RAC (distance from root apex to IAC) and probability of IAN injury. Multiple logistic regression modelling to determine the odds ratio of variables that made an important contribution to the probability of IAN injury and to adjust for confounding variables.
The U type ridge (46.7%) and the most concave point located at C zone (48.8%) are most prevalent in this region. The mandibular second molar presents highest risk for IAN injury than other tooth type (p<0.001), which were 3.82 times to occur IAN injury than the mandibular second premolar. The concave point located at A zone and B zone were 7.82 and 3.52 times than C zone to have IAN damage, respectively. The probability of IAN injury will reduce 26% for every 1mm increase in RAC (p<0.001).
The tooth type, morphological features of lingual concavities, and RAC are associated with risks of IAN injury during immediate implant placement.
Pre-surgical mapping of the IAC and identification of its proximity relative to the lingual concavity in the posterior mandible regions may avoid unpleasant complications, specifically when performing immediate implant procedures.
研究下颌后牙区即刻种植术中舌侧凹陷的发生率和形态学参数，以及这些因素是否与下牙槽神经（IAN）损伤的较高风险相关。
分析237名受试者（1008颗牙齿）的CBCT图像，包括下颌骨的形状（C型、P型、U型）、舌侧凹陷的尺寸参数（角度、高度、深度），及其与下牙槽管（IAC）的关系（A区、B区、C区）、根尖距下牙槽管距离（RAC）和IAN损伤概率。采用多元逻辑回归模型确定对IAN损伤概率有重要贡献的变量比值比，并对混杂变量进行校正。
该区域最常见的是U型牙槽嵴（46.7%），最凹点位于C区（48.8%）。下颌第二磨牙IAN损伤风险高于其他牙位（p<0.001），IAN损伤发生率是下颌第二前磨牙的3.82倍。位于A区和B区的凹点IAN损伤发生率分别是C区的7.82倍和3.52倍。RAC每增加1mm，IAN损伤概率降低26%（p<0.001）。
牙位、舌侧凹陷的形态特征和RAC与即刻种植时IAN损伤风险相关。
术前对IAC进行定位，并确定其在下颌后牙区与舌侧凹陷的相对位置，可避免不良并发症，特别是在进行即刻种植手术时。
