Suture fused: Metopic
Shape of Skull: Trigonocephalic
The skull shape in metopic synostosis is characteristically pointed at the forehead. (Trigono in Greek meaning triangle). This suture is normally the first one to close at approximately 6 months to 1 year. However in metopic synostosis it closes extremely early (usually before birth and restricts the growth of the forehead. Other features seen in trigonocephaly include hyportelorism (when the eye sockets are closer to each other with a narrow nasal bridge) as well as flaring of the bone under the eyebrows. Flaring is often so severe that the eye socket does not allow for protection of the eyes.
Metopic synostosis should not be confused with metopic ridging which can sometimes cause a ridge at the front of the skull but is not associated with the hyportelorism and the flaring of the orbital rims in the same manner as metopic synostosis. Metopic ridging can often be severe enough to be confused with metopic synostosis. It is a completely benign condition which in most cases resolves by the time the child is a teenager.
Metopic synostosis is increasing in incidence compared to the other types of synostosis and much research has been done to try and illusitate why this is. The current incidence has been calculated at 1 – 2 per 10,000 births
Procedure – The preferred treatment of the management of metopic synostosis is to perform a fronto-orbital advancement (FOA) and anterior cranial vault remodelling (ACVR). This involves the removal of the forehead bone, the bone of the upper part of the eye sockets and two thirds of the front part of the skull to reshape it into a more normal and acceptable shape.
Age at treatment – We prefer to undertake this surgery between 9 months and 15 months of age where the bones are soft enough to remodel into a better shape but strong enough to allow the use of dissolvable plates and screws to maintain the new shape of the skull.