13 December 2022

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Chewing performance assessed via smartphone

Lara Figini

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Since masticatory function and nutritional status are interconnected, impaired chewing can favor the development of frailty and sarcopenia. Therefore, the evaluation of masticatory parameters can be especially important in the geriatric age.

There are several types of objective tests of chewing efficiency or chewing performance. However, many require special equipment and are cumbersome to perform.

The two-tone mixing test, as originally described by Liedberg and Öwall, relies on an individual's ability to orally knead a two-color elastic sample, using wax. Subsequently, chewing gum was used and based on this principle, Prinz et al. have developed a first computer analysis to evaluate the degree of color mixing.

However, this workflow requires a flatbed scanner, and this could be a barrier for larger epidemiological studies or nursing homes.

One solution could be to simplify the image acquisition procedures. Digitizing and developing smartphones with advanced cameras could be one way to reduce complexity in this area.

Materials and methods

In a study published in the Journal of Oral Rehabilitation in October 2022, the authors evaluated the reliability of images obtained by smartphone cameras in the analysis of chewing performance using a color mixing ability test.

Participants were recruited into three groups (n = 20 each):

• Group 1, subjects with removable partial dentures
• Group 2, fully dentate subjects
• Group 3, subjects with full dentures.

After performing a color mixing ability test on each participant, the images of the chewing gum sample (Hue Check Gum©) were acquired with two smartphones and compared with the images obtained with a flatbed scanner by two examiners.

Images were analyzed by subjective evaluation (SA) and optoelectronic evaluation (VoH). The intra- and inter-rater camera reliability was tested.

ANOVA models with repeated measures analysis were used for the statistics (⍺ = .05).

Results

All imaging techniques were able to distinguish chewing performance between the three groups.

For SA, inter-rater reliability was found to be fair to substantial, and intra-rater reliability was found to be substantial to near-perfect.

For VoH the inter-rater reliability with smartphones was sometimes different between the two raters, but the intra-rater assessment was reliable. The optoelectronic analysis revealed that the smartphone images significantly underestimated the masticatory performance compared to the scanner analysis.

Seven-day aging of the samples did not markedly affect the results.

Conclusions

From the data of this study, the authors concluded that the assessment of masticatory performance with Hue-Check Gum© is a reliable method.

Smartphone use can occasionally underestimate chewing performance; image acquisition with a scanner remains the best method for this type of assessment. A centralized analysis of the photographed wafer can promote the reliability of the diagnosis.

Martin Schimmel et al. “Assessing masticatory performance with a colour-mixing ability test using smartphone camera images.” J Oral Rehabil. 2022 Oct;49(10):961-969. doi: 10.1111/joor.13352. Epub 2022 Jun 30.