Final answer:
Amelogenesis Imperfecta affects enamel development leading to discoloured and weakened teeth. The discolouration occurs due to oxidation of unsaturated fatty acids present in the teeth, resulting in yellowish-brown or greyish stains.
Step-by-step explanation:
Amelogenesis Imperfecta (AI) is a genetic condition that affects the development of enamel, the hard, protective outer layer of the teeth. The clinical appearance of hypomineralised teeth caused by AI includes significant discolouration of the enamel. This discolouration can be understood as a consequence of a deficiency disease process, where unsaturated fatty acids present in tooth structures undergo oxidation, transforming into peroxide. This chemical alteration results in a change in enamel color, often leading to yellowish-brown or greyish stains that are indicative of the enamel's hypomineralization. As a result, teeth may also be more prone to damage and decay due to their weakened structure.