The Frankfort Plane (also called the Frankfort Horizontal Plane) is an anatomical reference line commonly used in anthropometry, orthodontics, and craniofacial measurements. It is defined as the plane that passes through two specific points on the skull: the lowest point on the margin of the orbit (orbitale) and the uppermost point of the opening of the ear (tragion). When a person's head is positioned with the Frankfort Plane horizontally aligned, their head is considered in the "natural" or "neutral" position.
What is the Use of the Frankfort Plane in Anthropometry?
Standardize Measurements
Ensures that head measurements (like head height, facial angles, and cranial dimensions) are taken from a consistent orientation, improving accuracy and repeatability.
Compare Across Populations
With a common reference point, anthropometric data becomes more comparable across different populations and studies.
How was the Frankfort Plane First Discovered?
The Frankfort Plane was established as an international standard in anthropometry in 1884 during the Anthropological Congress in Frankfort, Germany, where scientists sought a standardized plane for head measurements. This plane helped unify measurements and improve the comparability of cranial and facial metrics. By aligning different cranial measurements along a standardized horizontal line, researchers were better able to develop comparative datasets on human morphology across populations.
How to Find the Frankfort Plane?
1. Identify the Key Points
To locate the Frankfort Plane on a person or a skull:
Find the tragion (the top point of the ear canal opening) and the orbitale (the lowest point on the lower border of the eye socket). These points define the Frankfort Plane.
2. Align the Plane Horizontally
Position the head so that the plane passing through these two points is level, placing the head in a natural posture.
3. Visualize or Use Instruments
For manual measurements, you might use visual alignment with guides or rely on imaging software in digital measurements.
In a clinical or anthropometric setting, aligning the head to the Frankfort Plane often requires specific equipment and careful observation to ensure accuracy.
Instruments Needed to Find the Frankfort Plane
Protractor or Goniometer
Useful for checking the angles and ensuring the Frankfort Plane alignment when measuring facial or cranial features.
VIEW PRODUCTSMirror or Leveling Device
For manual alignment, a mirror or leveler can help visually check that the Frankfort Plane is horizontal.
VIEW PRODUCT
