部份恒牙先天缺失是牙颌畸形常见先天病因之一。当先天缺牙并伴有其它某些局部、全身或遗传因素时,畸形可能更加复杂,给治疗带来一定的困难。有关先天缺牙问题,早在100多年前已有报告,其发生率为2.3～6.0%,可能缺失一个或多个乳牙或恒牙,缺失最多者为下颌第二双尖牙,其次为上颌侧切牙,上颌第二双尖牙,下颌中切牙。本文的目的是探讨 One of the common causes of congenital malformations is one of the common causes of congenital absence of some permanent teeth. When the birth of missing teeth and accompanied by some other local, systemic or genetic factors, the deformity may be more complex, to bring some difficulties in treatment. About the birth of tooth problems, as early as 100 years ago, there have been reports, the incidence was 2.3 to 6.0%, may lack one or more deciduous teeth or permanent teeth, missing the largest second mandibular premolar, followed by maxillary incision Teeth, maxillary second bicuspid, mandibular central incisor. The purpose of this article is to explore