学龄儿童正处于替牙期,在多种因素的影响下,一部分儿童表现出各种形式的牙替换异常,如乳牙滞留、双排牙、恒牙迟萌、乳牙早脱等.对1997年4月本地区在校小学生口腔病普查中发现的520例替牙异常儿童资料进行分析,以探讨其异常的特点、原因,并提出防治对策.1 对象与方法 School-aged children are in the period of tooth replacement, and under the influence of many factors, some children show various forms of tooth replacement abnormalities, such as deciduous teeth, double row teeth, permanent teeth late adolescent, early deciduous teeth, etc. In 1997 4 In this area, 520 cases of abnormal teeth were detected in the survey of oral diseases among school pupils to investigate the characteristics and causes of the abnormalities and to put forward the countermeasures.1 Object and method