Final answer:
The odontoid process of the C2 vertebra is best seen using an open mouth, end-on radiographic view, which is crucial for assessing fractures or misalignments in this area.
Step-by-step explanation:
The best structure seen using an open mouth, end-on radiographic view is the odontoid process (also known as the dens) of the C2 vertebra, or axis. This radiographic view is often referred to as the 'open mouth view' or 'odontoid view' and is particularly used by health professionals to assess for any fractures or misalignments in this area. The odontoid process is pivotal for the rotation of the head and can be vulnerable to injury from trauma. The cheek, tongue, and palate typically frame the oral cavity in this type of view, but it's the odontoid process that is specifically highlighted. This professional dental imaging technique is crucial for diagnosing issues related to the cervical spine.