Frontal suture

The frontal suture, also known as the metopic suture, is a fibrous joint that divides the two halves of the frontal bone of the skull in infants and young children. It extends from the bregma (the intersection of the coronal and sagittal sutures) down to the nasion (the point where the frontal and nasal bones meet).

Typically, the frontal suture begins to fuse during the first few months after birth and is usually completely closed by the age of six to eight years. This process is known as metopic synostosis. Once fused, the frontal bone becomes a single, unified bone.

In some individuals, the frontal suture may persist into adulthood, a condition known as a persistent metopic suture. This is considered a normal anatomical variation and is usually asymptomatic. However, it can sometimes be mistaken for a fracture on radiographic images.

Premature fusion of the frontal suture (metopic synostosis) can result in a cranial deformity known as trigonocephaly, characterized by a triangular-shaped forehead. This condition may require surgical intervention to correct the skull shape and allow for proper brain growth.