Teodoro Ana B, Evangelista Karine, Rangel Goulart Douglas, Olate Sergio, Valladares-Neto José, Soares Cevidanes Lucia H, Alves Garcia Silva Maria
Universidade Federal de Goiás - Programa de Pós-Graduação, Faculdade de Odontologia, Goiânia, Goiás, Brasil.
Universidade Federal de Goiás - Divisão de Ortodontia, Faculdade de Odontologia, Goiânia, Goiás, Brasil.
Acta Odontol Latinoam. 2025 Apr;38(1):20-28. doi: 10.54589/aol.38/1/20.
The mandible presents morphological variations, even in individuals without syndromes. This variability will determine different skeletal sagittal patterns, generally classified as Class I, II or III. The anatomical position of the mandibular canal has been investigated in different skeletal patterns, often using cone-beam computed tomography (CBCT) images, for diagnostic or surgical planning purposes.
The aim of this study is to perform a three-dimensional analysis of the position of the mandibular canal (MC) in adults with Class I, II and III skeletal patterns, by means of segmentation and 3D measurements on CBCT images.
75 CBCT images were obtained from a secondary database, and 3D analysis was performed using ITK-SNAP and 3D Slicer software. The 3D evaluation consisted of determining the orientation of the position of the mandible, segmentation of the mandible and the MC, creating 3D models, and establishing anatomical landmarks. Vertical (supero-inferior, SI), transverse (mediolateral, RL,) and 3D measurements were performed.
The position of the MC is modified according to the skeletal pattern and by morphological factors of the mandible such as sex and gonial angle. The proximity of the MC to the oblique line is smaller in the SI direction in Class III, and the position of the MC is associated with variation in the gonial angle. It may be closer to the cortical lingual in the central region.
The mandibular canal position should be considered in tomographic evaluation during diagnosis and therapeutic planning of mandible surgeries, especially in cases of sagittal ramus osteotomy.
即使在没有综合征的个体中，下颌骨也存在形态变异。这种变异性将决定不同的骨骼矢状面模式，通常分为I类、II类或III类。下颌管的解剖位置已在不同的骨骼模式中进行了研究，通常使用锥形束计算机断层扫描（CBCT）图像，用于诊断或手术规划目的。
本研究的目的是通过对CBCT图像进行分割和三维测量，对I类、II类和III类骨骼模式的成年人下颌管（MC）位置进行三维分析。
从二级数据库中获取75张CBCT图像，并使用ITK-SNAP和3D Slicer软件进行三维分析。三维评估包括确定下颌骨位置的方向、下颌骨和MC的分割、创建三维模型以及建立解剖标志。进行了垂直（上下，SI）、横向（内外侧，RL）和三维测量。
MC的位置根据骨骼模式以及下颌骨的形态因素（如性别和下颌角）而改变。在III类中，MC在SI方向上与斜线的距离较小，并且MC的位置与下颌角的变化有关。在中央区域，它可能更靠近舌侧皮质。
在诊断和下颌骨手术治疗规划的断层评估中，应考虑下颌管的位置，尤其是在矢状支截骨术的情况下。
