Intraoral X-rays display electromagnetic photos from inside the mouth, while extraoral X-rays showcase the view from outside the mouth, according to WebMD. Occlusal X-rays display the upper and lower dental arches from an overhead view, and bite-wing X-rays provide a frontal picture of the upper and lower teeth when clenched.
Orthodontists most commonly use bite-wing X-rays to assess the alignment of both arches. The periapical point of view displays the inside of each individual tooth from the crown to the root, including inner nerves and canals. This view allows dentists to better detect cavities and other instances of decay in the mouth.