Levesque G Y, Demirijian A, Tanguay R
J Dent Res. 1981 Oct;60(10):1735-41. doi: 10.1177/00220345810600100201.
Bilateral agenesis was encountered in about 9% of the cases, with no significant sexual difference. The right and left mandibular third molars had the same pattern of development and emergence. The slight advance of girls over boys at the crown-completion stage was similar to previous observations on other mandibular teeth, particularly the second molar. The root development course of the third molar was faster in males than in females; this sexual dimorphism was much greater for retarded cases than for advanced cases. At the apex closure, the difference between median ages of males and females was 1.5 yr. Alveolar emergence tended to occur at a lower developmental stage in advanced cases compared with retarded cases.
双侧牙胚缺失在约9%的病例中出现，无明显性别差异。左右下颌第三磨牙具有相同的发育和萌出模式。在牙冠完成阶段，女孩比男孩略有提前，这与先前对其他下颌牙齿（尤其是第二磨牙）的观察结果相似。男性第三磨牙的牙根发育进程比女性快；这种性别差异在发育迟缓的病例中比发育提前的病例中更为明显。在根尖闭合时，男性和女性的中位年龄差异为1.5岁。与发育迟缓的病例相比，发育提前的病例牙槽萌出往往发生在较低的发育阶段。
