Scaphocephaly is due to premature closure of the –
**Core Concept**
Scaphocephaly is a type of craniosynostosis characterized by an elongation of the skull, typically resulting from premature closure of one or more cranial sutures. This condition leads to an abnormal skull shape, often with a narrow forehead and a long, narrow skull.
**Why the Correct Answer is Right**
In scaphocephaly, the premature closure of the sagittal suture (Option A) is the primary cause. The sagittal suture is a fibrous joint that runs along the midline of the top of the skull, separating the two parietal bones. Premature closure of this suture restricts the normal growth of the skull, resulting in an elongated shape. The sagittal suture is the most common suture to close prematurely, leading to scaphocephaly.
**Why Each Wrong Option is Incorrect**
* **Option B:** Premature closure of the coronal sutures would lead to brachycephaly, not scaphocephaly. The coronal sutures are located at the sides of the skull and, when closed prematurely, result in a short, broad skull shape.
* **Option C:** Premature closure of the lambdoid sutures would lead to a condition known as dolichocephaly, not scaphocephaly. The lambdoid sutures are located at the back of the skull and, when closed prematurely, result in an abnormally long skull shape.
* **Option D:** Premature closure of the metopic suture would lead to a condition known as trigonocephaly, not scaphocephaly. The metopic suture is a suture that runs down the middle of the forehead and, when closed prematurely, results in a triangular-shaped forehead.
**Clinical Pearl / High-Yield Fact**
Craniosynostosis is a condition where one or more cranial sutures close prematurely, restricting normal skull growth and leading to abnormal skull shapes. Early diagnosis and treatment are essential to prevent complications such as increased intracranial pressure and vision problems.
**Correct Answer: A. Premature closure of the sagittal suture.**