- Patients are in prone or seated erect position with the arms in comfortable position and adjust shoulders to lie in the same transverse plane.
- Midsagittal plane of the patient head is center to the midline of the grid.
- Adjust flexion of the neck so orbitomeatal line forms an angle of 37 degrees with the plane of the film.
- Midsagittal plane is perpendicular to the plane of the film.
- Immobilize the head and center the cassette at the level of acanthion.
- Central ray is perpendicularly to exit the acanthion.
- Structure shown: axial image of the facial bones is presented. Orbits, maxillae and zygomatic arches are well shown.
- Evaluation criteria: distance between the lateral border of the skull and orbit should be equal on each side. Petrous ridges should be projected immediately below the maxillae.
Parietoacanthial Modification
- Orbitomeatal line is adjusted to be approximately 55 degrees with the plane of the film.
- The resulting radiograph demonstrates the facial bones with less axial angulation than using Water’s Method.
- Structure shown: Petrous ridges are projected immediately below the inferior boarder of the orbits.
