中国西北地区人群恒牙牙根变异的锥束CT观察

Detection of root variations of permanent teeth in a northwestern Chinese population by cone-beam computed tomography

目的:分析西北地区汉族人恒牙牙根变异的规律。方法:调取在西安市第四军医大学口腔医学院放射科接受锥束CT扫描病人的CT图像资料,病人共500人(男性246例,女性254)。观察并计算各类牙根变异的牙齿发生率和个体发生率。男女组间、双侧同名牙间率的比较采用卡方检验,左右侧不对称性采用Spearman等级相关性分析。结果:双根型下颌尖牙的发生率为0.63%(3/474人)。上颌第一前磨牙多根的发生率为30.28%(132/436人),下颌第一前磨牙Tomes根为13.45%(60/446人)。双侧上颌第二磨牙3根的发生率为57.48%(219/381人),下颌第一磨牙远舌根变异为31.98%(134/419人),下颌第二磨牙融合根为41.77%(165/395人)。除3根型下颌第一磨牙外,上述其他各项牙根变异性别差异均具有统计学意义(P<0.05)。结论:熟悉掌握汉人恒牙的牙根变异规律具有重要的临床价值。

AIM： To investigate the prevalence of root variations in a northwestern Chinese population.METHODS： Cone-beam computed tomography images of dentitions were collected retrospectively from 500 Chinese patients（246 males and 254 females）.The incidences of the root variations were determined.The trait frequency differences between both genders and both sides were tested using Chi-square tests.Correlations in the expression of the trait between antimeric teeth were analyzed with the Spearman rank correlation test.RESULTS： The prevalence was 0.63%（3/474 individuals）,for 2-rooted lower canine 30.28%（132/436 individuals） for multi-rooted upper first premolar,13.45%（60/446 individuals） for Tomes’ root（lower first molar）,57.48%（219/381 individuals） for bilateral 3-rooted upper second molars,31.98%（134/419 individuals） for 3-rooted lower first molar and 41.77%（165/395 individuals） for single-rooted lower second molar.Sex difference was statistically significant（P〈0.05） for all the above root variations except three-rooted mandibular first molars.CONCLUSION： Understanding the prevalence of root variation in Chinese population is useful for dental treatment.