Normative Data and Reliability of the Test of Masticating and Swallowing Solids (TOMASS) in Healthy Brazilian Adults

The Test of Masticating and Swallowing Solids (TOMASS) is a standardized clinical assessment designed to quantify oral phase swallowing efficiency during solid food intake. Although TOMASS has been investigated in several countries, normative data for the Brazilian population are still lacking.

To establish normative data and investigate the reliability of the Brazilian Portuguese version of TOMASS in healthy adults.

This observational cross-sectional study included 99 healthy adults stratified by age group. Individuals with dysphagia, head and neck cancer, neurological disorders, or gastrointestinal diseases were excluded. Participants underwent sociodemographic assessment, Montreal Cognitive Assessment (MoCA), oral structural evaluation, and TOMASS administration using a commercially available Cream Cracker biscuit available in Brazil. All assessments were video-recorded for subsequent analysis. Test-retest reliability was assessed through repeated administrations of TOMASS, and inter-rater reliability was analysed using video recordings. The analysed variables included the number of bites, the number of masticatory cycles, the number of swallows, and total ingestion time. Statistical analyses included Student's t-test, ANOVA with Bonferroni post hoc tests, Wilcoxon test, and ICC coefficient.

The sample included 99 healthy adults distributed across three age groups, with 54% women, a mean age of 50.2 (±16.3) years, mean education level of 12.4 (±4.1) years, and monthly household income equivalent to approximately two minimum wages (US$478 ± US$228). Significant differences were found between age groups in the number of masticatory cycles (p = 0.021), specifically between the 20-40 and 61+ age groups (p = 0.040). Significant differences were also observed in total task time (p < 0.001), with contrasts between the 20-40 and 61+ groups (p = 0.002), as well as between the 41-60 and 61+ groups (p = 0.013). Test-retest reliability ranged from moderate to excellent, and inter-rater reliability demonstrated good to excellent agreement across TOMASS variables.

The Brazilian Portuguese version of TOMASS demonstrated satisfactory reliability and applicability for assessing mastication and swallowing performance in healthy Brazilian adults. The present study also provides normative reference data that may support future clinical and research applications of TOMASS in Brazil.

What is already known on the subject The quantitative variables obtained through the TOMASS protocol contribute to the diagnostic accuracy of mastication abilities during a clinical swallowing examination (CSE), supporting more precise clinical decision-making, particularly when compared with previously established normative values. Moreover, the quantitative data allow for monitoring biomechanical changes over time, whether due to natural processes such as aging, neurofunctional maturation, or spontaneous recovery, or attributed to the efficacy of specific therapeutic interventions. What this paper adds to existing knowledge Normative TOMASS data for the Brazilian population may serve as clinical guidelines for assessing chewing and swallowing functions, given that the test is easily integrated into clinical evaluations due to its low cost and quick administration. These data may be especially relevant in contexts where socioeconomic, cultural, and physical barriers, a reality for a significant portion of the Brazilian population, still limit access to healthcare. What are the potential or actual clinical implications of this study? The clinical implications of this study are significant for speech-language pathologists in Brazil and other professionals involved in swallowing assessment and rehabilitation. The establishment of normative TOMASS data for the Brazilian population provides a valuable reference for identifying deviations in mastication performance across age and gender groups. Moreover, in low-resource contexts and developing countries, a brief, easy-to-administer, and low-cost protocol such as TOMASS is especially valuable, enabling equitable access to standardized assessment and monitoring of masticatory and swallowing functions.