Sperber G H, Moreau J L
University of Alberta, Edmonton, Canada.
Int Endod J. 1998 Mar;31(2):117-22. doi: 10.1046/j.1365-2591.1998.00126.x.
A study of 480 extracted first permanent mandibular molars of the Oulof people of Senegal, West Africa, revealed 15 teeth with three roots (3.12%), and 120 teeth with four root canals (25%). An extra root correlated with a sextum lingual tubercle in 20% of cases. Analysis of the pulp chambers revealed a variety of rectangular shapes. Comparison of these anomalies with their incidence in other ethnic groups extends the range of incidence of three-rooted first permanent mandibular molars in the Negroid race. This trait is described for only the second time in a Negroid population. The clinical consequences of root variation in root canal treatment are considered.
一项针对西非塞内加尔奥洛夫人群480颗拔除的下颌第一恒磨牙的研究显示，有15颗牙齿有三根（3.12%），120颗牙齿有四个根管（25%）。在20%的病例中，额外的牙根与舌侧结节相关。髓腔分析显示出各种矩形形状。将这些异常情况与其在其他种族群体中的发生率进行比较，扩展了尼格罗人种中下颌第一恒磨牙三根发生率的范围。这一特征在尼格罗人群中是第二次被描述。文中还考虑了根管治疗中牙根变异的临床后果。
