Oblique line of mandible

The oblique line of mandible is a subtle ridge found on the outer surface of the body of mandible. It begins at the sharp anterior border of the ramus of the mandible and extends forward and downward to an area just below the mental foramen, ending near the mental tubercle.

This oblique line of mandible is important because it’s where several muscles attach. For example, the buccinator muscle, which presses the cheek against the teeth, originates from the oblique line, going as far backward to the front edge of the first molar tooth. Also, two muscles involved in moving the mouth–the depressor anguli oris, which pulls down the mouth’s corner, and the depressor labii inferioris, which lowers the lower lip–both arise from the oblique line, right below the mental foramen.