The “puffed-cheek” technique for evaluation of the oral cavity was described by Weissman and Carrau.
It is indicated in patients with proven or suspected oral cavity lesions .
Instrucions to the patient:
The patient is asked to close the lips and blow uniformly until the cheeks are fully puffed out.
This can be sufficient if the suspected lesion is located exclusively in the vestibule.
The air filling the space provides excellent contrast against the mucosal surfaces and can also help move the buccal mucosa away from the teeth and minimize the effect of metal denture steak artifacts on its contour.
In cases of suspected lesions of the OCP it is necessary to instruct the patient to position the oral tongue in the center of the OCP,
without touching the hard palate,
floor of the mouth or gingival mucosa [Fig. 4].
The patient can breathe quietly during the scanning.
Some suggested protocols include the “puffed cheek” technique as a supplementary scan (from hard palate to inferior edge of mandible,
no additional contrast used),
carried out after a global contrast enhanced examination (from skull base to upper mediastinum) .
In our department we often incorporate the “puffed cheek” technique in the venous and/or arterial phase of the examination in patients with oral cavity tumors.
The protocol can be modified depending on the individual situation.
In some cases,
repetition of the maneuver on consecutive scans is beneficial and yield better quality images.
The contemporary multidetector row CT scanners with extended volume coverage allow greater temporal and spatial resolution.
Depending on the stage the tumors of the oral cavity can have different imaging features.
Most often they present as irregular segmental thickening of the mucosal surface with or without enhancement on contrast examination [Fig. 5, Fig. 8]. Some present as small or large exophytic structures [Fig. 7,
Fig. 9] or ulcerative lesions [Fig. 10] that disrupt the normal smooth contours of the mucosal surface.
It is important to assess whether the lesion is localized in just one mucosal region or spreads across neighboring ones.
Difficult situations to consider
Intense metal streak artifacts usually obstruct (and sometimes make impossible) the exact evaluation of the oral tongue.
[Fig. 3] This is a frequent problem in Bulgaria,
considering the poor oral status of the progressively aging population and the wide use of metal elements in dental reconstructions.
Some patients may have difficulties performing the technique and may require additional training,
which adds more time to the procedure.
Those are usually patients with neurological (central of peripheral facial paralysis) or psychiatric disorders or recent surgery.
In patients who do not comply with the correct positioning of the tongue in the “puffed cheek” technique the “open mouth” maneuver can be used for better assessment of the hard palate and the dorsal surface of the tongue as it is more easily performed by some people.