Gebre-Emanuel TakaFikremariam Gillamichael2018-08-072023-11-052018-08-072023-11-051986-09http://etd.aau.edu.et/handle/123456789/11097A cross-sectional study of the prevalence of dental fluorosis among Nazareth high school student population and determination of the concentration of fluoride in the water supply of the town was carried out in June 1986. Of the 4092 9th, l0th and 11thgrades student population 1023 (25%) students were selected for dental examination and interview by the process of random sampling method using table of random numbers. Out of the 1023 students, 821 (80 . 3%) responded to the study. Of the 821, 334 (40 . 7%) are born in nazareath , 58 (7.1%) are born in Jonji , Koka , lolenchiti and metehara and the remaining 429 students (52 . 2%) are born in other places and arrived to live in Nazareth at different year of their ages. The prevalence of dental fluorosis among the High School student population is found to be 38 . 2% with no statistically significant difference between the males (36 . 9%) and females ( 40 . 9%)(x2 = 0 . 77 , x295 ( 1 d. f) = 3.84 , x299 (1 d.f) = 6 .63,P ", 0 . 01 , P 0 . 05) and the prevalence among those born and brought up in naztreath is 69 . 1% with significant difference when comnared to those who have come to live in Nazareath at different times of t heir age(x2= 232 . 19, x2 99 ( ) d . £) = 11.34 , (p < 0 : 01) . There is also statistically significant difference among the difference age groups with the young er age groups the percent being high (x2= Yf . 22 , x299 (~ d . fJ = 13 . 27 , P <0 . 01 ) .Water samples from three functioning sources of water Supply Students in Nazareath for trle to',1n ( g wells junction- main suppliers of t he town for the last 23 year s , Deke- Hadiand High way \l; ells - recently dug or on us e tV10 wells ,1983, 1984 respectively) are also analyzed and there sults indicate high fluoride level (5.30, 1.32, and1.16mg/liter of water , respectively .Thus there is an association between the fluoride content of the water supply and the prevalence of dental fluorosis in those that are born and brought up in Nazareath and those that have arrived t o Nazareath at an earlier age of their life .enDental Fluorosis, Students ,NazareathThesis