Porion

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Porion is an anatomical landmark located on the human skull. It is a crucial point used in craniometry and cephalometry for various measurements and analyses in fields such as anthropology, forensic science, and dentistry.

Location

The porion is situated at the uppermost point of the external opening of the external acoustic meatus, which is the ear canal. It is located on the temporal bone of the skull, specifically at the superior margin of the external auditory meatus.

Significance in Craniometry

In craniometry, the porion is used as a reference point for measuring the dimensions of the skull. It is often used in conjunction with other landmarks such as the nasion, bregma, and inion to determine the cranial index and other cranial measurements.

Significance in Cephalometry

In cephalometry, the porion is used to assess craniofacial morphology. It is a key point in the construction of cephalometric radiographs, which are used to diagnose and plan treatment for orthodontic and orthognathic conditions. The porion is often used in combination with the orbitale to establish the Frankfort horizontal plane, a standard plane of reference in cephalometric analysis.

Related Anatomical Landmarks

• Nasion: The midpoint of the frontonasal suture.
• Bregma: The junction of the coronal and sagittal sutures.
• Inion: The most prominent point of the external occipital protuberance.
• Orbitale: The lowest point on the inferior margin of the orbit.

Applications

The porion is used in various applications, including:

• Anthropology: For studying human evolution and variation.
• Forensic science: For identifying individuals based on skull measurements.
• Dentistry: For planning orthodontic treatments and surgeries.

See Also

• Craniometry
• Cephalometry
• Frankfort horizontal plane
• Temporal bone
• External acoustic meatus