Intraoral ultrasonic scanning as a diagnostic aid.

Since ultrasonographic examination has the advantages of being non-invasive, rapid and easily reproducible, this technique can be a valuable aid in diagnosing oral lesions. However, the relatively large size of commercially available transducers and the acoustic attenuation by the air space within the oral cavity have been deterrents to the intraoral application of this technique. To resolve these problems a small intraoral transducer was developed and employed clinically in the diagnosis of oral soft tissue lesions. Performance tests reveal that this transducer provides 1mm axial resolution and 2 mm lateral resolution with a 30 mm focus. It can be easily employed within the oral cavity, using a small water bag or polymer gel as an acoustic coupling agent to the oral mucosa. Clinical application of this technique to oral soft tissue lesions allows definition of margins, size and location of lesions, and their relationship to adjacent structures, as well as discrimination between cystic, benign or malignant nature, by the sonic character. These results suggest that intraoral ultrasonic scanning can be useful in the diagnosis of oral soft tissue lesions.