Dental OSCE (Objective Structured Clinical Examination) Practice Exam

What is a key characteristic of ectodermal dysplasia?

1. Delay in dental eruption

2. Excessive hair growth

3. No teeth or hair

4. Advanced cavities

The correct answer is: No teeth or hair

A key characteristic of ectodermal dysplasia is the presence of abnormalities in structures derived from ectoderm, which includes hair, teeth, and sweat glands. Individuals with this condition often have fewer or absent teeth (anodontia) and sparse or absent hair, which aligns with the characteristic of "no teeth or hair." This lack of development is due to the genetic mutations affecting the pathways that lead to the formation of these ectodermal structures. While the other options describe various dental and physical manifestations, they do not encompass the defining feature of ectodermal dysplasia as directly as the absence or significant reduction of teeth and hair does. For example, delay in dental eruption can occur due to various dental conditions but is not exclusive to ectodermal dysplasia. Similarly, excessive hair growth is contrary to what is typically observed in this condition, which usually involves sparse hair. Advanced cavities may arise in individuals with any dental condition but are not specifically indicative of ectodermal dysplasia itself. Thus, the defining aspect of this condition is indeed the absence or extreme scarcity of teeth and hair.