The enamel may be hypoplastic, hypo mineralized or both and teeth affected may be discolored, sensitive or prone to disintegration either post-eruption or pre-eruption. 2 It may be associated with morphologic or biochemical changes elsewhere in the body. 3 Hypoplastic AI represents 60-73% of all cases; hypo-maturation AI represents 20-40%, and hypo-calcification AI represents 7%. 4 The most widely accepted classification is that proposed by Witkop and Sank in 1976. Aldred and Crawford also

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... sed a new classification. Witkop and Rao, (1971) classified AI broadly based on phenotype and style of inheritance 5 into three categories: Hypoplastic variety, hypocalcified variety, and hypo maturation variety. Aldred and Crawford in 1995 6 classified based on a molecular defect, biochemical result, mode of inheritance and phenotype. Dental enamel, a highly mineralized tissue has over 95% of its volume being occupied by unusually large, highly organized, hydroxyapatite crystals. 2 The formation of enamel has been highly organized, and unusual structure is thought to be rigorously controlled in ameloblasts. This has been through the interaction of a number of organic matrix molecules. 7