The frontal bone, specifically its squamous (flat) part, forms the skeleton of the forehead, articulating inferiorly with the nasal and zygomatic bones. In some adults a frontal suture persists; this remnant is called a metopic suture. It is in the middle of the glabella, the smooth, slightly depressed area between the superciliary arches. The frontal suture divides the frontal bones of the fetal cranium.