Human sexual dimorphism is associated with many biological characteristics, including dental variables. To investigate if molars fused roots present sex-associated differences. Panoramic radiographs were used to investigate the frequency and distribution of permanent molars fused roots. Only patients with all first and second permanent molars were included. Third molars were not investigated. Any molar with roots fused apical to the usual furcal position were considered molar fused roots. Comparisons between males and females were performed using chi-square or Fisher’s and Mann-Whitney tests and the established alpha was 5% (p<0.05). Sex-differential liability models were also proposed. A total of 84 males and 86 females were included and 1360 molars were analyzed. Among them, 46 (26.06%) present at least one molar with fused root. Second maxillary molars were the most affected teeth. There was an association between sex and molars with fused roots. Females had a 3.4 higher chance to present fused roots than males (OR=3.4, CI 95% 1.6–6.8; p=0.0008). The female: male ratio of molars with fused roots was 2.5:1. The number of molars with fused roots ranged from 1 to 6 per patient, and the mean number of Females presented more molars with fused roots (mean = 1.01; standard deviation = 1.52) than males (mean = 0.31; standard deviation = 0.85) (p<0.05). Molar fused root of permanent teeth presents sex-associated differences, in which females are more affected than males. Our results support sex-differential liability models for molars fused roots.

中文翻译：

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探索磨牙融合根的性别相关差异

人类的性别二态性与许多生物学特征有关，包括牙齿变量。调查融合牙根的磨牙是否存在性别相关差异。使用全景X光片来研究恒磨牙融合根的频率和分布。仅包括所有第一和第二恒磨牙的患者。未检查第三磨牙。任何牙根与通常的分叉位置融合的磨牙都被认为是磨牙融合根。使用卡方或 Fisher 和 Mann-Whitney 检验进行男性和女性之间的比较，确定的 alpha 为 5%（p<0.05）。还提出了性别差别责任模型。总共包括 84 名男性和 86 名女性，并分析了 1360 颗磨牙。其中，46颗（26.06%）至少有一颗磨牙具有融合牙根。第二上颌磨牙是受影响最严重的牙齿。性别和具有融合根的磨牙之间存在关联。女性出现融合根的几率比男性高 3.4（OR=3.4，CI 95% 1.6–6.8；p=0.0008）。具有融合牙根的女性与男性的比例为2.5:1。每个患者的牙根融合磨牙数量为 1 至 6 颗，女性牙根融合磨牙的平均数量（平均值 = 1.01；标准差 = 1.52）多于男性（平均值 = 0.31；标准差 = 0.85）（ p<0.05）。恒牙磨牙融合根存在性别差异，其中女性比男性受影响更大。我们的结果支持磨牙融合根的性别差异责任模型。