Which plane intersects the right and left porion and left orbitale?

The Frankfort horizontal plane is a widely recognized reference plane in cephalometrics, used in orthodontics and craniofacial analysis. It is defined as a plane that passes through two specific points: the right and left porion, which are the highest point of the external auditory meatus, and the left orbitale, which is the lowest point on the orbital rim. This plane is crucial for establishing a standardized orientation of the skull, allowing for consistent measurements and comparisons across different individuals.

By intersecting these key anatomical landmarks, the Frankfort horizontal plane helps practitioners evaluate the craniofacial relationships and assess cephalometric measurements accurately, which is essential for diagnosis and treatment planning in orthodontics and maxillofacial surgery. Thus, it serves as the basis for many analyses, providing a horizontal reference that accounts for the natural variations in skull orientation.