Purpose: To describe the different patterns of the intraoral distribution of enamel fluorosis in permanent dentition. Materials and Methods: This cross-sectional analysis was conducted in Nalgonda district of Andhra Pradesh, India. A group of 1000 school children aged 13-15 years were selected by stratified cluster sampling from four different areas with different levels of naturally occurring fluoride in the drinking water. Fluorosis was recorded using the Thylstrup and Fejerskov index (TFI). Results: The prevalence of fluorosis (TFI score >=1) was 100% at all four fluoride levels. This study revealed two patterns of fluorotic enamel changes in dentition. In high fluoride areas, incisors exhibited lower TFI values than canines, premolars and molars, with the maximum affected being second molars followed by first molars. In low fluoride areas, a steeper profile of dental fluorosis, starting from incisors and first molars through canine and premolars to second molars, was noticed. Conclusion: With the exception of permanent second molars and permanent first molars in high fluoride communities, the intraoral distribution of different degrees of dental fluorosis was related to the completion of primary enamel formation. Keywords: dental fluorosis, TF index