The standard central-ray angle for the PA axial (Caldwell) projection of the skull is:

The respiration phase for all projections of the skull and sinuses is:

Which bone has condyles that articulate with the atlas of the cervical spine?

The sinuses are named after the bones they are found in.

The superior aspect of the sphenoid bone contains a deep depression that contains the:

Which of the following bones contain sinuses?1.) ethmoid2.) frontal3.) sphenoid

Which main sinuses are projected through the mouth on the open-mouth modification of the Waters method?

For the Waters method, the orbitomeatal line is placed at what angle to the IR?

For each of the following diagrams, match the name of the positioning/anatomical landmark or positioning line by placing the letter to the left of the choices listed.       

If the patient cannot flex the neck to place the required baseline  perpendicular to the IR for an AP axial (Towne) projection, which line should be substituted and placed perpendicular?