Association of Tongue Strength and Maximum Incisal Opening with Oral Intake in Persons with Head and Neck Cancer Treated with Radiotherapy: A Retrospective Study

Persons treated with radiotherapy (RT) for cancer of the head and neck (HNC) may experience limited oral intake at treatment completion. The purpose of this retrospective study was to examine the contributions of tongue strength and maximum incisal opening (MIO) to oral intake in a cohort of veterans treated for HNC. Medical records of veterans diagnosed with HNC treated with RT who were seen by the Speech Pathology Service prior to and throughout treatment per usual care were reviewed for this study; eighty-two records met the inclusion criteria for analysis. Tongue strength in kPa, MIO in mm, feeding tube status at completion of RT, and food and liquid consistencies consumed at completion of RT were among the data abstracted from the records. Most veterans (67%) did not have a feeding tube present at the completion of RT and reported drinking thin liquids (84.2%) at treatment completion. Eighteen percent reported including all food consistencies in their diet at the end of treatment. Both MIO and tongue strength decreased after treatment. Greater tongue strength during RT and larger MIO at the completion of RT were predictive of improved functional outcomes for oral intake at the end of treatment. This study provides evidence of the importance of increasing tongue strength and MIO during treatment with RT, and supports an important focus for intervention by speech-language pathologists.