Ghaeminia H, Meijer G J, Soehardi A, Borstlap W A, Mulder J, Bergé S J
Department of Oral and Maxillofacial Surgery, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
Int J Oral Maxillofac Surg. 2009 Sep;38(9):964-71. doi: 10.1016/j.ijom.2009.06.007. Epub 2009 Jul 28.
This study investigated the diagnostic accuracy of cone beam computed tomography (CBCT) compared to panoramic radiography in determining the anatomical position of the impacted third molar in relation with the mandibular canal. The study sample comprised 53 third molars from 40 patients with an increased risk of inferior alveolar nerve (IAN) injury. The panoramic and CBCT features (predictive variables) were correlated with IAN exposure and injury (outcome variables). Sensitivity and specificity of modalities in predicting IAN exposure were compared. The IAN was exposed in 23 cases during third molar removal and injury occurred in 5 patients. No significant difference in sensitivity and specificity was found between both modalities in predicting IAN exposure. To date, lingual position of the mandibular canal was significantly associated with IAN injury. CBCT was not more accurate at predicting IAN exposure during third molar removal, however, did elucidate the 3D relationship of the third molar root to the mandibular canal; the coronal sections allowed a bucco-lingual appreciation of the mandibular canal to identify cases in which a lingually placed IAN is at risk during surgery. This observation dictates the surgical approach how to remove the third molar, so the IAN will not be subjected to pressure.
本研究调查了锥形束计算机断层扫描（CBCT）与全景X线摄影相比，在确定下颌阻生第三磨牙与下颌管的解剖位置关系方面的诊断准确性。研究样本包括来自40例下牙槽神经（IAN）损伤风险增加患者的53颗第三磨牙。全景X线摄影和CBCT特征（预测变量）与IAN暴露和损伤（结果变量）相关。比较了两种检查方式预测IAN暴露的敏感性和特异性。在拔除第三磨牙过程中，23例IAN暴露，5例发生损伤。在预测IAN暴露方面，两种检查方式的敏感性和特异性无显著差异。迄今为止，下颌管的舌侧位置与IAN损伤显著相关。CBCT在预测第三磨牙拔除过程中IAN暴露方面并不更准确，然而，它确实阐明了第三磨牙牙根与下颌管的三维关系；冠状面图像能够从颊舌侧观察下颌管，以识别手术中舌侧IAN有风险的病例。这一观察结果决定了拔除第三磨牙的手术方法，从而使IAN不会受到压迫。
