**Question:** Premature exfoliation of deciduous teeth is seen in

A. Xeroderma Pigmentosum
B. Hypomineralized teeth
C. Down syndrome
D. Vitamin D deficiency

**Correct Answer:** B. Hypomineralized teeth

**Core Concept:** Premature exfoliation of deciduous teeth refers to the early shedding of milk teeth before they reach their expected age of replacement by permanent teeth. This issue can be caused by various factors affecting tooth mineralization and development.

**Why the Correct Answer is Right:** Hypomineralized teeth are characterized by incomplete or abnormal mineralization, which leads to weakened tooth structure and an increased susceptibility to dental caries and premature exfoliation. In this case, the primary teeth do not develop properly, resulting in fragile dentition that cannot withstand the normal forces of mastication (chewing) and is more prone to dental caries. This leads to early exfoliation of the milk teeth.

**Why Each Wrong Option is Incorrect:**

A. Xeroderma Pigmentosum: This is a rare genetic disorder characterized by an increased sensitivity to sunlight and an increased risk of skin cancer. It is unrelated to dental issues and premature tooth exfoliation.

B. Vitamin D deficiency: Although vitamin D is essential for bone mineralization, its deficiency would primarily affect the overall growth and development of the child, not specifically tooth mineralization and exfoliation.

C. Down syndrome: While Down syndrome patients may have dental abnormalities, premature tooth exfoliation is not a common feature of this condition.

**Clinical Pearl:** Premature exfoliation of deciduous teeth can be a manifestation of dental fluorosis, which is caused by excessive fluoride intake during tooth development. In such cases, the teeth may exhibit abnormal color, shape, and exfoliation.

**Correct Answer Explanation:** The correct answer is B (Hypomineralized teeth). Premature exfoliation of deciduous teeth can be observed in cases of hypomineralized teeth due to abnormal mineralization, resulting in fragile dentition that does not withstand the normal forces of mastication and is more susceptible to dental caries. This leads to early shedding of the milk teeth.