Department of Oral and Maxillofacial Radiology, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
BMC Oral Health. 2021 Sep 5;21(1):428. doi: 10.1186/s12903-021-01785-9.
Juxta-apical radiolucency (JAR) has been presented as a radiographic sign, suggestive of the IAN injury through third molar surgery. This study aimed to evaluate the relation of JAR with IAN injury in cone-beam computed tomography (CBCT) images and to determine whether the presence of JAR is related to tooth angulation, proximity to the mandibular canal, position to the IAN, and thinning of the cortical plates.
Of an initial sample of 545 mandibular third molars, a total of 75 JAR and 75 JAR teeth were evaluated by CBCT. We assessed the relationship between the presence of JAR in cone-beam computed tomography (CBCT) images and the presence of IAN injury after mandibular third molar surgeries. Moreover, we investigated whether the presence of IAN injury is related to tooth angulation, proximity to the mandibular canal, position to the IAN, and thinning of the cortical plates. Descriptive statistics, Chi-square test, and Fisher's exact test were performed for statistical analysis.
A significant relationship was found between JAR and temporary IAN injury (P = 0.036). However, there was no case of permanent IAN injury. IAN injury showed no significant relationship with the tooth angulation, position to IAN and proximity to the mandibular canal, lingual cortical plate thinning, sex, and age.
JAR is generally in contact with the mandibular canal, and some degree of cortical thinning can be found in most cases. In this study, JAR was significantly related to temporary IAN injury. JAR may increase the risk of nerve injury during the surgical removal of third molars.
近根尖放射性透亮区（JAR）被认为是一种放射学征象，提示通过第三磨牙手术损伤下牙槽神经（IAN）。本研究旨在评估 CBCT 图像中 JAR 与 IAN 损伤的关系，并确定 JAR 的存在是否与牙齿倾斜度、与下颌管的接近度、与 IAN 的位置以及皮质板变薄有关。
在最初的 545 个下颌第三磨牙样本中，共有 75 个 JAR 和 75 个 JAR 牙齿通过 CBCT 进行评估。我们评估了 CBCT 图像中 JAR 的存在与下颌第三磨牙手术后 IAN 损伤之间的关系。此外，我们还研究了 IAN 损伤的存在是否与牙齿倾斜度、与下颌管的接近度、与 IAN 的位置以及皮质板变薄有关。统计分析采用描述性统计、卡方检验和 Fisher 确切检验。
JAR 与暂时性 IAN 损伤之间存在显著关系（P=0.036）。然而，没有永久性 IAN 损伤的病例。IAN 损伤与牙齿倾斜度、与 IAN 的位置和与下颌管的接近度、舌侧皮质板变薄、性别和年龄之间无显著关系。
JAR 通常与下颌管接触，并且在大多数情况下可以发现一定程度的皮质变薄。在本研究中，JAR 与暂时性 IAN 损伤显著相关。JAR 可能会增加在第三磨牙手术中损伤神经的风险。
