2.1. Mixing ability test

The mixing ability test (MAT) consists of two layers of wax, with the colours red and blue (Plasticine modelling wax, non‐toxic DIN EN‐71, art. 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. The outcome variable is called the Mixing Ability Index (MAI), and ranges between 5 and 30, where a lower MAI score implies a better mixed tablet and better masticatory performance. A subject was asked to chew on this tablet 20 times in order to mix the two colours. The tablet is then flattened, pressed to a thickness of 2 mm and scanned on both sides using a high‐quality scanner (Epson^® V750). The scanned images are then processed using Adobe Photoshop CS3 extended (Adobe). The histograms of both sides of the flattened and scanned wax tablet are added to obtain red and blue intensity distributions. The spread of the colour intensities is measured. 12 Subjects were instructed to chew 20 times on two different tablets in order to test reliability. The interim period between the two tests was approximately 2 hours for patients with HNC and 30 minutes for healthy controls, with the same testing conditions for all participants.