Metopic Synostosis (Trigonocephaly)
Metopic synostosis is more common than previously recognized. Today metopic synostosis represents 20-25% of all isolated craniosynostosis. The head shape that results from metopic synostosis is called trigonocephaly because the back of the head is broad and flat and the forehead is narrow and pointed. The metopic suture provides width to the forehead. When it closes prematurely the forehead is very narrow with a prominent vertical ridge and the eye sockets (orbits) are abnormally close together.
It is common for patients to be referred to me for evaluation for metopic craniosynostosis because of the midline ridge. The metopic suture normally closes between 6-9 months of age. When any suture closes it tends to thicken. If the head shape is otherwise normal and the child is age 6 months or older with a midline ridging of the forehead, it is unlikely that they have metopic craniosynostosis. If you still have concerns you should be seen by a craniofacial surgeon.
The severity of head shape and appearance changes in metopic craniosynostosis can vary. These changes can range from thickening of the suture with mild narrowing of the forehead to the most severe form, with a severely pointed forehead, ridge, close set eyes and a triangular head shape. Why there is such variability is not clear. It is possible that the severity relates to the timing of suture closure during pregnancy. Regardless, if you have concerns for metopic synostosis you should be evaluated by a craniofacial surgeon. In clear cut cases of severe disease, the concerns for elevated pressure that can occur in the skull (about 15%) and the appearance issues that will result from the deformity make the decision to operate easier to make. For those patients with moderate severity, you will have to discuss the functional and appearance issues with the surgeon to determine the appropriate treatment for your child.
Metopic craniosynostosis is typically treated with fronto-orbital advancement (FOA). The goal of treatment is to restore a normal contour to the forehead and upper portion of the eye sockets. This procedure is done at 9-12 months of age. Read more about fronto-orbital advancement.