中文摘要：

目的了解西藏那曲藏族学生氟牙症流行情况及发病因素。方法采用单纯随机抽样的方法，对12～17周岁的471名藏族学生进口腔检查和问卷调查，氟牙症按Dean分类法，采用SPSS for Windows11．5进行统计分析，饮用酥油茶与氟牙症的相关性分析用Mantel—Haenszel．X^2检验。结果氟牙症患病率为53．5％，氟牙症指数为1．09，属中度流行地区；饮用水源氟化物含量不高（0．03～0．34mg／L），当地常用茶叶的氟化物含量高于内地（t=3．445，P〈0．05），氟牙症的发生与饮用酥油茶呈高度正相关（X^2MH=9．865，P〈0．01；OR=2．065，P〈0．01）。结论7岁前长期大量食用酥油茶是当地藏族学生氟牙症流行的主要病因，即属于砖茶型氟牙症；建议调整饮食结构，改进茶叶品质，减少酥油茶摄入量，以降低氟牙症的患病率。

英文摘要：

Objective To investigate the etiological factors and prevalence of dental fluorosis among Tibetant students in Naqu, Tibet. Methods Simple random sample method was used and 471 Tibetant students aged from 12 to 17 years old were involved in the oral check- up and questionaire. Dental fluorosis were classified according to Dean method. SPSSll. Five was applied to analysis the data. Mantel - Haenszel X^2 test was used to evaluate the relativity between ghee - tea drinking and dental fluorosis. Results The prevalence rate of dental fluorosis was 53.5 %. The index of dental fluorosis was 1.09, and the dental fluorosis was belong to middle degree prevalent region. Content of fluoride was not too much in the drinking water（0.03- 0.34mg/L）. The fluoride contents in local tea was much more than inland （t= 3. 445, P 〈 0.01 ）. The incidence of dental fluorosis was positively correlated to the quantity of ghee- tea. （X^2=9.865, P 〈0.01;OR=2.065, P 〈 0. 01） . Conclusion The main causes of dental fluorosis is taking too much ghee - tea in a long time before 7 years old among Tibetant students, that is the brick - tea type of dental fluorosis. In order to reduce the prevalence rate of Dental fluorosis, it is recommended that adjust the food composition, improve the quality of tea and reduce the in - take quantity of ghee - tea.