CAMRT Radiography Practice Exam

What should be superimposed on an AP Odontoid?

1. Mandible and base of the skull

2. Upper incisors and the base of the skull

3. Nasal bones and frontal bone

4. Occipital bone and ethmoid bone

The correct answer is: Upper incisors and the base of the skull

In an anteroposterior (AP) projection of the odontoid (also known as the dens), the ideal positioning requires that the upper incisors be aligned with the base of the skull. This alignment is crucial for accurately visualizing the odontoid process while minimizing potential distortion. When the upper incisors are superimposed on the base of the skull, it indicates that the patient's head is correctly positioned in a neutral manner. This positioning is vital as it ensures that the odontoid process is properly centered and its anatomical structures are clearly visible. If the head is tilted or rotated, it can lead to misrepresentation of the odontoid's relationship with surrounding structures, which is essential for diagnosing conditions related to the cervical spine, such as fractures or instability. Other options involve superimpositions that would not provide the necessary anatomical clarity for evaluating the odontoid. For instance, the mandible and base of the skull, nasal bones and frontal bone, or occipital and ethmoid bones do not directly relate to the positioning critical for visualizing the odontoid process effectively. Therefore, the choice of superimposing the upper incisors with the base of the skull is the correct approach for an accurate AP Odontoid