**Core Concept**
Wormian bones are small, irregular bones found within the sutures of the skull, particularly in the lambdoid and coronal sutures. They are a normal anatomical variation and are more commonly found in individuals with certain genetic syndromes or conditions, such as osteogenesis imperfecta.

**Why the Correct Answer is Right**
Wormian bones are a result of the incomplete closure of the cranial sutures during fetal development. They are usually found in the lambdoid and coronal sutures, but can be present in other sutures as well. The presence of Wormian bones is often an incidental finding and does not typically cause any clinical symptoms. However, their presence can be associated with certain genetic syndromes or conditions.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Wormian bones can be found in individuals with Down syndrome.
**Option B:** This option is incorrect because Wormian bones can be found in individuals with osteogenesis imperfecta.
**Option C:** This option is incorrect because Wormian bones can be found in individuals with craniosynostosis.

**Clinical Pearl / High-Yield Fact**
Wormian bones are an important radiological finding that can be associated with certain genetic syndromes or conditions. They are often incidental findings on imaging studies, but can provide valuable information for diagnosis.

**Correct Answer: D**