Metopic sutures closes at ?
**Core Concept**
The metopic suture is a fibrous joint that separates the two halves of the frontal bone in the skull. It plays a crucial role in the development and growth of the cranial vault. The closure of the metopic suture is a significant anatomical landmark that occurs during infancy and childhood.
**Why the Correct Answer is Right**
The metopic suture typically closes by the age of 6 months to 1 year. This process is influenced by the growth and development of the frontal bone, which is driven by the deposition of bone matrix and the activity of osteoblasts. As the frontal bone grows, the metopic suture gradually closes, and the two halves of the bone eventually fuse together.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the metopic suture typically closes by the age of 6 months to 1 year, not at birth.
**Option B:** This option is incorrect because the metopic suture does not usually close after the age of 6 years.
**Option D:** This option is incorrect because the timing of the metopic suture closure can vary, but it is generally not associated with puberty.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the closure of the metopic suture is a normal anatomical process that occurs during infancy and childhood. However, persistent or abnormal closure of the metopic suture can be a sign of underlying cranial abnormalities or developmental disorders.
**Correct Answer: C. 6 months to 1 year.**