Objectives

To assess C-shaped root canal configuration by identifying its prevalence and each configuration type proportion, according to tooth (mandibular first or second molar) and demographic characteristics in a Brazilian population, using cone-beam computed tomography (CBCT). Moreover, it was verified if there is a relationship between root canal configuration observed in two-dimensional reconstructions of CBCT and presence of C-shape.

Methods

Mandibular jaw CBCT scans (184 males and 220 females, aged 15 to 80 years), which presented 1464 mandibular molars (710 first molars and 754 second molars), were assessed. Teeth were evaluated for the presence and type of C-shaped root canals by observing the roots at five levels in CBCT axial reconstructions. Root canal configuration was assessed in panoramic reconstructions. Data were statistically analyzed at a significance level of 5%.

Results

Of the 1464 mandibular molars, 125 (8.5%) were classified as C-shaped. This variation was more prevalent in females (n = 107, 85.6%) and in second molars (n = 108, 86.4%). C1 (uninterrupted C-shaped canal) was the most prevalent type of C-shaped configuration (41.76%), while C5 (no canal lumen) was the least prevalent type (0.96%). Single root with single canal in panoramic reconstructions was the most predominant configuration for C-shaped teeth (n = 54, 43.2%). Fused roots presented 17.2 higher odds of being associated with C-shaped root canals than non-fused roots.

Conclusions

C-shaped root canals were more prevalent in mandibular second molars and in females. Additionally, clinicians should bear in mind the greater possibility of C-shaped configuration in mandibular molars with fused roots.

Clinical relevance

Mandibular molars with C-shaped canals present a clinical challenge. A higher C-shaped proportion was noted in radiographic fused root types, which had 17.2 higher odds of presenting such anatomy when compared to radiographic non-fused roots. Root radiographic features may help in diagnosis of complex C-shaped morphologies.

中文翻译：

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巴西亚人群的下颌磨牙中的C形管：使用锥形束计算机断层摄影术的患病率和根管构型。

目标

通过使用锥形束计算机断层扫描（CBCT）根据巴西人群的牙齿（下颌第一或第二臼齿）和人口统计学特征，通过确定其流行程度和每种形态类型的比例来评估C形根管形态。而且，已经证实在CBCT的二维重建中观察到的根管构型与C形的存在之间是否存在关系。

方法

评估了下颌颌CBCT扫描（男184例，女220例，年龄15至80岁），共扫描了1464例下颌磨牙（710个第一磨牙和754个第二磨牙）。通过观察CBCT轴向重建中五个层次的牙根，评估牙齿的C形根管的存在和类型。在全景重建中评估了根管结构。以5％的显着性水平对数据进行统计分析。

结果

在1464个下颌磨牙中，有125个（8.5％）被分类为C形。这种变化在女性（n  = 107，85.6％）和第二磨牙（n  = 108，86.4％）中更为普遍。C1（不间断的C形管）是最流行的C形配置类型（41.76％），而C5（无管腔）是最不流行的类型（0.96％）。全景重建中单根单根管是C形牙齿的最主要结构（n  = 54，43.2％）。融合根比不融合根具有更高的17.2几率与C形根管相关。

结论

C形根管在下颌第二磨牙和女性中更为普遍。此外，临床医生应记住，根部融合的下颌磨牙具有C形构型的可能性更大。

临床相关性

具有C形管的下颌磨牙提出了临床挑战。在射线照相融合根类型中注意到较高的C形比例，与射线照相非融合根相比，呈现这种解剖结构的几率高17.2。根部放射学特征可能有助于诊断复杂的C形形态。