A 13 year old male patient complains about the discoloration of his teeth. His mother shows a similar discoloration of her teeth. Clinical findings reveal teeth with mottled, opaque white brown yellowish discoloration. Snowcapped appearance of teeth is appreciable. OPG reveals a thin layer of enamel over the cusp tips and interproximal surfaces. Probe test is positive. Based on the findings, this condition occurs due to disturbances at which stage of tooth formation?
Histodifferentiation marks the end of the proliferative stage as the cells lose their capacity to multiply. This stage is the forerunner of appositional activity. Disturbances in the differentiation of the formative cells of the tooth germ result in abnormal structure of the dentin or enamel. One clinical example of the failure of ameloblasts to differentiate properly is amelogenesis imperfecta. The failure of the odontoblasts to differentiate properly, with the resultant abnormal dentin structure, results in dentinogenesis imperfecta.
Note: Aberrancy in the stages of tooth development will result in following anomalies-
           Initiation/proliferation – supernumerary teeth, partial anodontia and odontomas
           Histodifferentiation – Amelogenesis and Dentinogenesis imperfecta
           Morphodifferentiation – Peg teeth, talons cusp, mulberry molars, microdontia and macrodontia
           Apposition – Enamel hypoplasia.
Proliferation
Histodifferentiation
Morphodifferentiation
Apposition