any structural anomaly of the part of the face above the eyes; in human anatomy, the forehead is the fore part of the head, an area of the head bounded by three features, two of the skull and one of the scalp; the top of the forehead is marked by the hairline, the edge of the area where hair on the scalp grows while the bottom of the forehead is marked by the supraorbital ridge, the bone feature of the skull above the eyes; the two sides of the forehead are marked by the temporal ridge, a bone feature that links the supraorbital ridge to the coronal suture line and beyond