Graduate Program in Dentistry, School of Life Sciences, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil.
Graduate Program in Dentistry, Latin American Institute of Dental Research and Education (ILAPEO), Curitiba, Brazil.
Minerva Stomatol. 2020 Dec;69(6):377-383. doi: 10.23736/S0026-4970.20.04374-5. Epub 2020 Jul 21.
During dental implants placement and bone augmentation procedures, it is important to determine the presence and location of mandibular canal anatomical variation in order to avoid injuries to inferior alveolar bundle. This study aimed to describe the prevalence and configuration of mandibular canal branching in the posterior region of the mandible using cone beam computed tomography (CBCT).
The interpretation of the images was conducted according to the presence, classification and location of the mandibular canal. Horizontal and vertical distances from mandibular canal in the ramus region to the molar region was recorded. CBCT images of 751 patients, 486 women (64.7%) and 265 men (35.3%), with a mean age of 54.57 (±13.23; 14-93) years, were interpreted by one calibrated examiner.
Out of 1502 hemi-mandibles images, mandibular canal variations were observed in 130 (8.6%). Sixty-four (49.2%) mandibular canal variations were identified on the right side and 66 (50.8%) on the left side. The mean distances between superior cortical of the mandibular canal and the base of mandible, buccal cortical of mandibular canal and buccal cortical bone, and superior cortical of mandibular canal and alveolar ridge were 12.16 mm (±2.68), 4.17 mm (±1.30), and 12.97mm (±4.01), respectively. Type I mandibular canal variation was the most frequent (68; 52.2%), followed by type III (34; 26.1%).
Prevalence of mandibular canal variations was 8.6%, type I was the most common and its direction showed proximity with lingual surface in the second molar region.
在牙种植体植入和骨增量手术中，确定下颌管解剖变异的存在和位置对于避免下牙槽束损伤非常重要。本研究旨在使用锥形束 CT（CBCT）描述下颌管在后区的分支的发生率和形态。
根据下颌管的存在、分类和位置对图像进行解读。记录下颌管在支区到磨牙区的水平和垂直距离。由一名经过校准的检查者对 751 名患者（486 名女性，占 64.7%；265 名男性，占 35.3%；平均年龄 54.57±13.23 岁，范围为 14-93 岁）的 CBCT 图像进行了解读。
在 1502 个半下颌骨图像中，观察到下颌管变异 130 例（8.6%）。右侧发现 64 例（49.2%）下颌管变异，左侧发现 66 例（50.8%）。下颌管上皮质与下颌骨基底、下颌管颊皮质与颊骨皮质、下颌管上皮质与牙槽嵴之间的平均距离分别为 12.16mm（±2.68）、4.17mm（±1.30）和 12.97mm（±4.01）。I 型下颌管变异最为常见（68 例，占 52.2%），其次是 III 型（34 例，占 26.1%）。
下颌管变异的发生率为 8.6%，I 型最为常见，其方向在第二磨牙区与舌侧表面接近。
