Frankfurt horizontal plane

The Frankfurt Horizontal Plane is a standard reference used in anatomy and dentistry to categorize the position of the head. It is a horizontal plane that extends from the lower border of the eye socket (orbit) to the upper edge of the external auditory meatus (ear canal). When a person's head is in a natural, upright position with this plane parallel to the ground, it helps ensure consistent and accurate measurements for medical, dental, and anthropological assessments. Essentially, it provides a common "baseline" for studying head and face structures.