Leite Guilherme Mariano Fiuza, Lana Juliana Pelinsari, de Carvalho Machado Vinícius, Manzi Flávio Ricardo, Souza Paulo Eduardo Alencar, Horta Martinho Campolina Rebello
Department of Dentistry, Pontifícia Universidade Católica de Minas Gerais, Belo Horizonte, MG, Brazil.
Surg Radiol Anat. 2014 Oct;36(8):795-804. doi: 10.1007/s00276-013-1247-5. Epub 2013 Dec 15.
The mandibular canal is a significant anatomical structure in implant dentistry, and cone beam computed tomography (CBCT) is an important diagnostic image modality in this field of dentistry. The aim of this study was to evaluate the frequencies of anatomic variations and lesions affecting the mandibular canal in CBCT images of the mandible produced for dental implant planning.
This cross-sectional study evaluated a sample of 250 CBCT examinations (500 mandibular canals). The inclusion criterion was CBCT examinations of the mandible requested for dental implant planning. The presence of anatomic variations and lesions affecting the mandibular canal was evaluated in the CBCT examinations. Moreover, the buccolingual position of the mandibular canal was evaluated in the molar region and in the ramus region. The CBCT exams were evaluated by one observer. The data were analyzed using descriptive and analytical statistics. The one-way ANOVA test was employed to compare the age between the anatomic variations. A paired t test was used to compare the buccolingual position between the molar region and the ramus region. Differences were considered significant when p values were lower than 0.05.
The anatomic variations detected were large-diameter mandibular incisive canal (51.6 %), ramification (12 %), and accessory mental foramen (3.2 %). No difference was observed in the age of the patients between the anatomic variations (p > 0.05). The identified lesions included hypomineralization of the canal walls (20.8 %), idiopathic osteosclerosis (8.8 %), osteolytic lesions (3.2 %), iatrogenic perforation of the mandibular canal (2.8 %), and fibro-osseous lesions (1.6 %). The distance between the mandibular canal and the vestibular cortical bone was higher in the molar region than in the ramus region (p < 0.05).
Anatomic variations and lesions affecting the mandibular canal were common findings in the CBCT images of the mandible produced for dental implant planning. An awareness of these alterations is important for dentistry because some of them might require treatment, change oral surgery planning and difficult inferior alveolar nerve anesthetic block.
下颌管是种植牙科中一个重要的解剖结构，锥形束计算机断层扫描（CBCT）是该牙科领域重要的诊断成像方式。本研究的目的是评估在用于牙种植规划的下颌骨CBCT图像中，影响下颌管的解剖变异和病变的发生率。
本横断面研究评估了250例CBCT检查（500个下颌管）的样本。纳入标准是因牙种植规划而进行的下颌骨CBCT检查。在CBCT检查中评估影响下颌管的解剖变异和病变的存在情况。此外，在磨牙区和升支区评估下颌管的颊舌位置。CBCT检查由一名观察者进行评估。数据采用描述性和分析性统计方法进行分析。采用单因素方差分析检验比较解剖变异之间的年龄。采用配对t检验比较磨牙区和升支区之间的颊舌位置。当p值低于0.05时，差异被认为具有统计学意义。
检测到的解剖变异包括下颌切牙管直径增大（51.6%）、分支（12%）和副颏孔（3.2%）。解剖变异之间患者的年龄未观察到差异（p>0.05）。识别出的病变包括管壁矿化不足（20.8%）、特发性骨硬化（8.8%）、溶骨性病变（3.2%）、下颌管医源性穿孔（2.8%）和纤维骨病变（1.6%）。磨牙区下颌管与前庭皮质骨之间的距离高于升支区（p<0.05）。
在用于牙种植规划的下颌骨CBCT图像中，影响下颌管的解剖变异和病变是常见发现。对这些改变的认识对牙科很重要，因为其中一些可能需要治疗、改变口腔外科手术规划并使下牙槽神经麻醉阻滞困难。
