Frankfort horizontal plane

The Frankfort horizontal plane is a standard reference line used in anthropology and orthodontics to orient the head. It runs from the lowest point of the eye socket (orbit) to the highest point of the cheekbone (zygoma). When the head is positioned so this line is horizontal (parallel to the ground), it provides a consistent way to measure and compare the angles and positions of facial features. This helps clinicians assess facial symmetry, growth, and development accurately across different individuals.