Evans R W, Darvell B W
School of Dental Science, University of Melbourne, Victoria, Australia.
J Public Health Dent. 1995 Fall;55(4):238-49. doi: 10.1111/j.1752-7325.1995.tb02376.x.
The purpose of this study was to determine an improved estimate of the critical period for susceptibility to fluorosis in human maxillary central incisors.
The fluorosis score, S, of the incisal (I), middle (M), and cervical (C) third divisions on the labial surface of right maxillary central incisors of subjects (a representative sample of 1,085 Hong Kong Chinese children aged 7 to 12 years surveyed in 1986) was determined according to the Chronological Fluorosis Assessment (CFA) Index. Subject data were grouped by month of birth relative to June 1978, when the designated concentration for waterborne fluoride in the community water supply was reduced from 1.0 to 0.7 mg/L. The analytical task was one of finding the correlation maximum in a system of 12 variates and adjustable parameters including the waterborne fluoride concentration, [F-], and the fluorosis score.
The main findings were: (1) the peak correlation of S vs [F-] for the male incisal third centered at 17.5 months after birth; (2) and six months later for females; (3) the correlation of S with [F-] is maximized for S(M) following S(I) by two months, and S(C) following S(M) by a further two months for both males and females; and (4) the critical period for exposure to fluoride is of about four months' duration for each third.
The maxillary central incisor, as a whole, appears most at risk to fluorosis from dietary fluoride between age 15 and 24 months for males and between 21 and 30 months for females.
本研究旨在确定人类上颌中切牙氟斑牙易感性关键期的更精确估计值。
根据按时间顺序的氟斑牙评估（CFA）指数，确定了受试者（1986年对1085名7至12岁的香港华裔儿童进行调查的代表性样本）右上颌中切牙唇面切缘（I）、中部（M）和颈部（C）三分之一区域的氟斑牙评分S。根据相对于1978年6月的出生月份对受试者数据进行分组，当时社区供水的水中氟化物指定浓度从1.0毫克/升降至0.7毫克/升。分析任务是在包括水中氟化物浓度[F-]和氟斑牙评分在内的12个变量和可调参数的系统中找到最大相关性。
主要发现如下：（1）男性切缘三分之一区域S与[F-]的峰值相关性出现在出生后17.5个月；（2）女性则在6个月后出现；（3）男性和女性中，S（M）比S（I）晚两个月达到与[F-]的相关性最大值，S（C）比S（M）再晚两个月达到最大值；（4）每个三分之一区域接触氟化物的关键期约为四个月。
总体而言，男性在15至24个月龄之间、女性在21至30个月龄之间，上颌中切牙因膳食氟化物导致氟斑牙的风险最高。
