What is Frankfurt plane?

Frankfurt plane is a plane created by drawing straight horizontal lines from the top of the ear canal to the lower edge of the eye along both sides of the human skull. The line is called the horizontal line of Frankfurt (FHL) and is an important reference point in medical imaging studies. The level itself is used as a standard reference in anthropometry - a science that studies human anatomy to describe variations of human characteristics.

The plane is also called the auriculo-orbital plane because it passes through the auriculus or ear and orbitalles or eye indictments. It was founded in 1884 in Frankfurt, Germany by the World Congress of Anthropology. The Frankfurt plane has become the main standard of measuring the skull, as it also identifies the normal plane in which the head is located parallel to the ground.

Because the Frankfurt plane serves as a scale for measuring the skull, it is also called the craniometric plane. This is simply a point on the skull or skull from which the measurement can be done. FloeNiometric measurements made on the outside of the skull have endocranial equivalents, which are points in the skull that corresponds to external measurements.

Craniometric measurements are an important factor in administering MRI and CT scan. In 1962, the World Federation of Radiology defined Reid's base line - a line derived from the Frankfurt level - as a zero plane to be used in medical imaging. This line extends the Frankfurt plane from the lower eye sockets across the ear point towards the back of the head to the center of the occipital bone at the bottom of the skull. The line can be graphically displayed with the head slightly back and tilted about 7 degrees from the horizontal Frankfurt plane.

In principle, however, the Frankfurt plane was designed as a reference framework for identifying skeletal variations in human anatomy from an anthropological point of view. The aircraft has set a standard for measuring the human body and comparing the differences inRasech by corresponding to these variations by known measurements for specific individuals. Because the middle way of the Frankfurt plane monitors the line of 0.827 inches (21 mm) below the center of the outer ear canal and differs from 0.20 to 3.82 inches (5-97 mm), as progresses at the lower limit of the eye, that is, the changes may be caused by differences in facial structures. It has been found that such variations are characterized by various racial types that begin to differ when the highest boundary of the side nasal sinus changes the direction.

In this respect, it has been found that different races share a relatively uniform level of changes in a certain extent of measurement. For example, British measurements were found to be concentrated up to 0.15 inches (3.75 mm) below the ears and 0.10 inches (2.66 mm) location below where the side sinus changes the direction. Similarly, it has been shown that Chinese measurements are located in the range of 0-0.20 inches (0-5 mm) under the ear canal and 0.40 inches (10-0 mm) below the point where the side sinus changes the direction. The meaning of these measurements has not yet beenl determined; However, the evolutionary impact of genetic divergence of the human species can reach far into the future.