The association between a mixing ability test and patient reported chewing ability in patients treated for oral malignancies

Abstract

Introduction: Mastication has been assessed in several ways in the past. Both patients reported and objective assessment methods have been developed. The University Medical Center (UMC) Utrecht has developed a mixing ability test (MAT) using a two-coloured wax tablet. The present study investigates the association between the mixing ability test and a chewing related questionnaire in patients treated for oral malignancies. Patients and methods:In a cohort study, patients treated for oral malignancies were assessed 4-6 weeks before and 4-6 weeks after treatment, as well as 6 months, 1 year and 5 years after treatment. The mixing ability test was assessed using 10 and 20 chewing strokes and was compared to seven questions about several aspects of mastication. Regression analysis was performed and density plots were drawn for statistical analysis. Results:One hundred and twenty-three patients were included in this study. The questionnaire was less predictive for the 10-chewing stroke test and the test was less discriminatory for different food types than the 20-chewing stroke mixing ability test. Three questions about the ability to chew solid, soft and thickened liquid food types were found to be significantly predictive for the 20-chewing stroke test.Threshold values on the mixing ability index were around 20 for the ability to chew solid food types and 24 for soft food types. Conclusion:The 10-chewing stroke mixing ability test is less suitable than 20-chewing strokes for patients with and treated for oral cancer. The 20-chewing stroke mixing ability test has a fair association with self-reported outcomes. K E Y W O R D Shead and neck cancer, masticatory performance, mixing ability, objective assessment, oral function, oral oncology, patient-reported outcome | 141 de GROOT eT al.

Tongue function and its influence on masticatory performance in patients treated for oral cancer: a five-year prospective study

“…Masticatory performance was assessed using the mixing ability test [11,12]. The subjects performed 20 chewing strokes on a two-colored (red and blue) room-temperature wax tablet, after which the tablet was flattened and the degree of colormixing was digitally assessed using specialized software.…”

“…The Mixing Ability Index (MAI) ranged from 0 to 30 (30 being the worst score possible), based on the spread of the color intensities in the combined image of both sides of the tablet. For patients with oral cancer, a MAI below 20 likely indicates a subject able to chew all food types, subjects scoring between 20 and 24 should be able to chew soft food types, and those scoring over 25 would be expected to have difficulty with both solid and soft food types [5,[12][13][14].…”

Reliability of the mixing ability test testing masticatory performance in patients with head and neck cancer and healthy controls

“…nos. crimson 52801 and blue 52809, Stockmar, Kalten Kirchen, Germany) 7,12,14,20 . The total thickness is 3 mm, with a diameter of 30 mm.…”

“…Because of this compromised mastication, tougher foods are more difficult to process because they require a higher muscle force and more chewing cycles 6 . Therefore, some patients switch their diet to softer foods, because the muscle force needed to break down food is too high 7 …”

“…Construct validity was positive in one method measuring mixing ability to test oral function: the mixing ability test (MAT) 12 . The MAT was specifically developed for patients with HNC, 7,12,14 consisting of a relatively soft material (wax), to make sure patients with compromised mastication would still be able to perform this test. This test has proven to be sensitive in measuring mastication in adults with dental deficits and children with cerebral palsy 15,16 .…”