Trigonocephaly

Trigonocephaly is a congenital condition due to premature fusion of the metopic suture, the joint between the two frontal bones of the skull, leading to a triangular forehead. The premature merging of the two frontal bones limits growth across the head while growth continues in parallel directions. It may occur as one component of a syndrome together with other abnormalities, or in isolated form. The medical term comes from the Ancient Greek trigonon, meaning triangle, and kephale, meaning head, while the word metopic derives from the Greek metopon, meaning forehead.