Objective:To investigate the relationship among the congenital hypodontia of mandibular incisor and malocclusion and the variation of medial distal dimension of mandibular canine.

探讨下颌恒切缺失情况,与颌畸形的关系以及下尖近中径的变化。

So this fetus presented seeral signs of trisomy 21, including the hypoplasia of the nasal bone, hypodontia, micrognathia, and hypospadias.

这样，本例胎儿显示21三体的若干：括鼻骨发育不全、发育不全、小颌和尿道下裂。