[Tumors of the oral cavity: the usefulness of dynamic CT]

To demonstrate the usefulness and importance of including "puffed-cheek" dynamic CT (PCCT) in the protocol for the diagnosis and staging of tumors of the oral cavity.

This is a prospective study of 62 (38 male and 24 female) patients with epidermoid carcinoma of the oral cavity diagnosed and treated at our hospital during an 18-month period. The site of the primary tumor was the tongue (n=19), floor of the mouth (n=3), lip (n=3), gums (n=6), retromolar trigone (n=7), buccal mucosa (n=8), and a combination of the last three locations (n=16). In addition to conventional CT examination, all patients underwent dynamic CT of the oral cavity while maintaining their cheeks puffed out.

PCCT provided additional information in 39 patients (63%), giving a better view of the tumor, its extension, or both. PCCT detected eight lesions (17%) that were not visible on the conventional CT study; these lesions were located in the tongue (n=3), retromolar trigone (n=1), buccal mucosa (n=3), and upper gum (n=1). PCCT was especially useful for evaluating lesions with superficial extension, in particular those in the buccal mucosa, retromolar trigone, and gums. PCCT provided no additional information about the tumors on the floor of the mouth.

The habitual contact between the mucosal surfaces of the oral cavity makes some clinically obvious lesions difficult to identify at CT. The interposition of air acts as a natural contrast, separating the gums from the mucosa of the buccomaseteric region; PCCT provides relevant information and should be included in the imaging workup in patients with tumors of the oral cavity.