Frankfurt line

Frankfurt horizontal plane or Frankfurt plane is an anatomical reference line used in the field of anthropology, dentistry, and other medical and scientific disciplines to establish a standardized orientation of the human skull. It is crucial for ensuring consistency in measurements and comparisons of cranial features across different individuals and populations.

Definition

The Frankfurt plane is defined as a horizontal plane passing through the point at the lower margin of the left orbit (the eye socket, specifically the infraorbital rim) and the upper margin of each ear canal or external auditory meatus. When a skull or a living person's head is oriented in such a way that the Frankfurt plane is horizontal, the skull is said to be in the Frankfurt horizontal.

History

The concept of the Frankfurt plane was first established during the International Anthropological Congress in Frankfurt am Main, Germany, in 1884. The purpose was to create a standard cranial orientation for anthropometric studies, facilitating consistent and comparable measurements of human skulls and heads across different studies and disciplines.

Applications

The Frankfurt plane is widely used in various fields:

• In anthropology, it is used for the study of human evolution, allowing researchers to compare cranial features of different human populations or species in a standardized manner.
• In dentistry and orthodontics, it serves as a reference for diagnosing and planning treatment for craniofacial anomalies and malocclusions.
• In forensic science, it helps in facial reconstruction and identification processes.
• In medicine, particularly in radiology and surgery, it is used to orient images or during surgical procedures involving the head and neck.

Importance

The adoption of the Frankfurt plane as a standard reference ensures that measurements of the head and facial features are not distorted by head tilt or orientation. This standardization is crucial for accurate comparisons, whether in clinical settings, research, or forensic investigations.

Controversies and Limitations

While the Frankfurt plane is widely accepted, there are discussions about its applicability across different ethnic groups and the potential need for adjustments or alternative reference lines in certain populations. Additionally, the identification of the precise landmarks can sometimes be challenging, especially in individuals with craniofacial abnormalities.

See Also

• Cranial anthropometry
• Human skull
• Orthodontics
• Forensic facial reconstruction