## **Core Concept**
Dolichocephaly, also known as scaphocephaly, refers to a condition where the head becomes elongated and narrow, resembling a boat. This condition arises due to the premature closure (synostosis) of certain cranial sutures. The main sutures involved in skull formation include the coronal, sagittal, lambdoid, and metopic sutures.

## **Why the Correct Answer is Right**
The correct answer involves understanding the effect of premature closure of specific sutures on skull shape. Premature closure of the **sagittal suture** leads to dolichocephaly. The sagittal suture runs along the midline of the skull, and its premature fusion restricts lateral growth of the skull, causing it to grow more in the anteroposterior direction, resulting in an elongated, narrow skull shape.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Premature closure of the coronal suture typically leads to brachycephaly (short and wide skull) or plagiocephaly if it occurs on one side, not dolichocephaly.
- **Option B:** This option might seem plausible but is not directly linked to dolichocephaly; its premature closure leads to different skull deformities.
- **Option D:** The lambdoid suture's premature closure can cause posterior plagiocephaly, characterized by an asymmetric flattening of the back of the skull, not dolichocephaly.

## **Clinical Pearl / High-Yield Fact**
A key clinical correlation to remember is that the type of cranial deformity (e.g., dolichocephaly, brachycephaly) often indicates which suture has undergone premature closure. Early diagnosis and intervention can significantly impact the management and outcome of these conditions.

## **Correct Answer:** . Sagittal suture.