A metopic suture is when the frontal suture of the skull fails to close completely or partially in childhood. The frontal suture is a naturally occurring division of the skull in babies and children that normally grows together and disappears by age eight. It is thought to happen more frequently in males than females, and statistics confirm it occurs with equal prevalence regardless of geographic region.
Relatively common, the metopic suture it thought to occur in as many as 10 percent of the population. This number includes all cases that do not close by ages six through eight, including cases where the skull closes in adolescence or later in life during adulthood. Varying levels of closure are possible, up to and including a complete opening with no fusion of the skull tissue whatsoever. The metopic suture is thought to occur due to artificial cranial deformation.
Metopic synostosis is one complication that can happen to the frontal suture of the skull. When this happens, the skull takes on a pointed shape. This gives the appearance of a triangular shaped forehead in childhood. It is possible to address this issue with surgery that rounds out the appearance of the face. Surgery should be done as early as possible, preferably before three months of age.
Once the surgery to fix the metopic synostosis has completed reshaping the skull, the brain will grow around and into the new area. Especially in childhood, the brain quickly responds to changes in the skull and reshapes itself, adapting easily. This surgery can be performed on an adult if necessary, though healing time is usually increased with age.
The frontal suture exists to allow an infant's head to easily bend during child birth. This allows the head to fit through the mother's birth canal. An infant's skull is made up of malleable soft tissue that hardens over time, in addition to the coming together of the frontal suture.
In some cases, a metopic suture may go undiagnosed well into adulthood. Individuals with this type of suture may have no idea they have the issue, as it does not actually present any specific clinical complication. Metopic synostosis can occur in any frontal suture and does not necessarily result in a metopic suture. On an x-ray, metopic suture looks like just a skull fracture that can occur from a head trauma.