Which statement best differentiates amelogenesis imperfecta from MIH and dental fluorosis?

• A. Amelogenesis imperfecta presents generalized enamel defects; MIH shows demarcated opacities with post-eruptive breakdown; fluorosis presents diffuse mottling.
• B. Amelogenesis imperfecta and MIH both show diffuse mottling; fluorosis shows demarcated opacities.
• C. MIH presents generalized enamel defects; amelogenesis imperfecta shows diffuse mottling.
• D. Fluorosis presents post-eruptive breakdown; MIH shows generalized defects.

Answer: (A)

The key idea is how the enamel defects are distributed and bordered. Amelogenesis imperfecta shows generalized enamel defects across the dentition, meaning most or all teeth are affected and the pattern is uniform or widespread. Molar-incisor hypomineralization presents with demarcated opacities—clear borders between affected and normal enamel—primarily on the first permanent molars and often the incisors, and the affected enamel is prone to post-eruptive breakdown. Dental fluorosis creates diffuse mottling that is spread across many teeth without sharp borders, reflecting excess fluoride exposure during enamel formation. So, generalized involvement for AI, demarcated opacities with breakdown for MIH, and diffuse mottling for fluorosis is the best way to differentiate them.