This technique is commonly used for other parts of the body such
as limbs and body cavities.
The film is located between the tongue and the lingual aspect of
the target teeth. The beam is angled at 90 degrees to the film and
the target. The target tooth/teeth should be in the middle of the
film and the surrounding structures included, when important - for
example, the ventral border of the mandible.
- Very accurate but use is limited to mandibular molars and premolars
2, 3 and 4. An extra-oral technique is possible for the maxillary
cheek teeth and mandibular premolar 1.
- If the angle between the tooth and the film is more than 15
degrees, use the bisecting angle technique to prevent gross distortion
of the image caused by increasing the Object Film Distance.
Parallel technique in mandible