Rodriguez Y Baena Ruggero, Beltrami Riccardo, Tagliabo Angelo, Rizzo Silvana, Lupi Saturnino-Marco
Prof, MD. University of Pavia, Department of Clinical Surgical, Diagnostic and Pediatric Sciences, P.le Golgi 2, 27100, Pavia, Italy.
PhD, DDS. University of Pavia, Department of Clinical Surgical, Diagnostic and Pediatric Sciences, P.le Golgi 2, 27100, Pavia, Italy.
J Clin Exp Dent. 2017 Feb 1;9(2):e259-e265. doi: 10.4317/jced.53234. eCollection 2017 Feb.
The aim of this study was to evaluate the ability to identify the contiguity between the root of the mandibular third molar and the mandibular canal (MC) in panoramic radiographs compared with Cone Beam-CT.
Panoramic radiographs of 326 third molars and CBCT radiographs of 86 cases indicated for surgery and considered at risk were evaluated. The following signs were assessed in panoramic radiographs as risk factors: radiolucent band, loss of MC border, change in MC direction, MC narrowing, root narrowing, root deviation, bifid apex, superimposition, and contact between the root third molar and the MC.
Radiographic signs associated with absence of MC cortical bone are: radiolucent band, loss of MC border, change in MC direction, and superimposition. The number of risk factors was significantly increased with an increasing depth of inclusion. CBCT revealed a significant association between the absence of MC cortical bone and a lingual or interradicular position of the MC.
In cases in which panoramic radiographs do not exclude contiguity between the MC and tooth, careful assessment the signs and risks on CBCT radiographs is indicated for proper identification of the relationships between anatomic structures. Panoramic radiography, Cone-Beam computed tomography, third molar, mandibular nerve.
本研究旨在评估全景X线片与锥形束CT相比，识别下颌第三磨牙牙根与下颌管（MC）之间毗邻关系的能力。
对326颗第三磨牙的全景X线片和86例拟行手术且被认为有风险的病例的锥形束CT（CBCT）图像进行评估。在全景X线片中评估以下征象作为危险因素：透射带、下颌管边界消失、下颌管方向改变、下颌管变窄、牙根变窄、牙根偏斜、双尖、重叠以及第三磨牙牙根与下颌管之间的接触。
与下颌管皮质骨缺失相关的影像学征象为：透射带、下颌管边界消失、下颌管方向改变和重叠。随着包绕深度增加，危险因素数量显著增加。CBCT显示下颌管皮质骨缺失与下颌管舌侧或根间位置之间存在显著关联。
在全景X线片不能排除下颌管与牙齿毗邻关系的情况下，为正确识别解剖结构之间的关系，建议仔细评估CBCT图像上的征象和风险。全景X线摄影、锥形束计算机体层摄影、第三磨牙、下颌神经。
