U of T researchers describe ’Joe Canadian’ tongue

3-D ultrasound reveals effects of tongue surgery on speech

New imaging research about tongue shape and volume before and after surgery should ultimately help surgeons decide how to best reconstruct tongue defects resulting from cancer surgery, says a team of researchers at the University of Toronto.

Tim Bressmann, a professor in the Department of Speech-Language Pathology, and his colleague Jonathan Irish, a professor in the Department of Otolaryngology and a head and neck cancer surgeon at Princess Margaret Hospital, are the first researchers to use 3-D ultrasound to assess both normal and partially resected tongues during the production of speech sounds. By measuring the 3-D topography of the tongue’s surface as each of 10 normal speakers produced a variety of speech sounds, Bressmann and Irish were able to describe basic mechanisms underlying the normal functioning of a tongue. This ultrasound data became the baseline to which partially resected tongues were compared.

“We used the data from the normal speakers to model a prototypical ’Joe Canadian’ tongue,” says Bressmann. “This is a first step toward assessing the biomechanical impact of different reconstructive techniques on tongue movement for speech. Now, we can work toward determining what the ideal method of reconstruction is for different lesion locations and extents, so that we can ensure optimum speech outcomes for every patient.”

The researchers are now collecting ultrasound data from more tongue cancer patients in order to build a database for surgeons who perform partial tongue resection surgeries. “The survival rate in tongue cancer is 70 to 80 per cent,” says Bressmann. “Therefore, surgeons need to do a very good job because people will often live with their reconstructions for a long, long time.”