**Core Concept**
Cranial synostosis scaphyocephaly is a congenital condition characterized by premature closure of one or more cranial sutures, leading to abnormal skull shape and increased intracranial pressure. The condition results from abnormal bone growth and fusion, often due to genetic or environmental factors.

**Why the Correct Answer is Right**
Scaphyocephaly, a type of craniosynostosis, is specifically associated with premature closure of the sagittal suture. This closure prevents the normal lateral expansion of the skull, leading to a scaphoid-shaped skull with an increased anteroposterior diameter. The sagittal suture, located between the parietal bones, plays a crucial role in this process.

**Why Each Wrong Option is Incorrect**
**Option A:** Premature closure of the metopic suture would result in trigonocephaly, not scaphyocephaly. The metopic suture is located between the two halves of the frontal bone and is involved in the development of the forehead and nasal bridge.
**Option B:** Premature closure of the lambdoid suture would result in a condition known as posterior plagioclasephaly, characterized by an asymmetrical posterior skull shape. This is distinct from scaphyocephaly.
**Option C:** Premature closure of the coronal suture would result in a condition known as coronal synostosis, characterized by a short, broad skull with an abnormal forehead shape. This is also distinct from scaphyocephaly.

**Clinical Pearl / High-Yield Fact**
It's essential to recognize the distinct characteristics of each type of craniosynostosis, as each has unique clinical and radiological features. A thorough understanding of the underlying anatomy and pathophysiology is crucial for accurate diagnosis and management.

**Correct Answer:** B. The sagittal suture.