Tom-ay-to, Tom-ah-to, TOMASS! Testing mastication and swallowing

Title: The Test of Masticating and Swallowing Solids (TOMASS): reliability,
validity and international normative data

Author: Huckabee, M.L., McIntosh, T., Fuller, L., Curry, M., Thomas, et. al

Journal: International Journal of Language & Communication Disorders

Year of Publication: 2018

Study design: multi-level programme design

Purpose: “The purpose of this programme of study was to establish further the newly developed TOMASS for use in clinical assessment.”

Population: 228 healthy adult male/females (20-80 years old) recruited from general public

Inclusion criteria: no (self) reported history of dysphagia, neurological disease, head neck cancer, or gastrointestinal illness/injury

Exclusion criteria: while not explicitly stated, people who had history of the above


I’d be rich if I had a nickel for every time I assessed (aka observe and internally analyzed) a patient chewing. I’d be even more rich for all the times I did this without actually knowing what was going on, essentially guessing how long it took to chew and swallow, how many times they had to chew, if they were able to move the solid bolus around cohesively, if they were taking a long time to enjoy the food or because of some type of impairment…millionaire


I’m talkin millionaire status folks! 😉


I don’t know about you, but my x-ray vision goggles I was promised from school still haven’t come in yet, and I’m starting to get oh-so-frustrated relying on my crystal ball to use at work.🔮

There’s gotta be a better way?!? 😩🤔

That’s just what the heroic Huckabee planned with this article and validated assessment tool.

You know when you’re frantically searching for the one shirt or shoe in your closet, only to find something else you completely forgot about? That’s how I happened to come back to this approach I’d been meaning to look into (for #IDK how many months🤦‍♀️😬). Well, we’re here now, so let’s dive in together 🙂


For all those people too busy to even read an abstract (hey, we’ve all been there 😉 ), the authors attempt to make the article simple and digestable similar to the crackers they use! They give you a brief history of why even look at this (um, because we clinicians have to rely solely on observations at bedside evaluations versus having something to compare objectively?!?!), and tell you why as a clinician, this applies to you!!

“Clinical application of the TOMASS may help identify dysphagic patients at bedside and provide a non-invasive measure of rehabilitation recovery.” p.145

To start the story off right, it’s good to know just where the idea of assessing how many times someone chews something even came from.

The study that started it all was the development of the Timed Water Swallowing Test (TWST) (Hughes & Wiles 1996). Essentially, participants were given 100-150 ml of water from a cup and instructed to “drink as quickly as is comfortably possible.” While this study gave info on efficiency and speed for swallowing and looked at ‘swallowing capacity,’ we all know that liquids is one thing, anything solid going into the mouth is a something totally different.🍕🎂

To make that point more clear, the authors also bring in Robbins et al. (1999) to the party (in my opinion always a good reminder reference anyway 😉 )

“Aspiration is known to occur more frequently with liquids than solid textures (Robbins et al. 1999) rendering this a more sensitive tool to this feature of swallowing pathophysiology.” p.154

To my surprise, there were more researchers who had actually looked at mastication abilities in healthy participants before and found some initial ranges! So that’s where Huckabee found herself, in the middle of something similar but different with liquid water, and finding a lacking of incorporating other variables like age and gender.

Something else interesting I learned– TOMASS was originally developed during a study for Parkinson’s disease-related swallowing impairment! Guess you really never know where you’ll end up 😀 .


On to what “TOMASS 2.0” found for us. . .

The authors tackled quite a bit, which I can surely appreciate being a ‘bang for your goodbetterbestbuck’ kinda girl. Not only did they look to establish TOMASS’s validity and reliability, they also compared 2 different (but remarkably similar) cracker stimuli as well as age and gender differences. If you thought that was impressive, they also went further to collect actual normative data (ya know, the thing we usually need to know if there even is a problem?)!

White total participants look pretty solid at first glance and from across the globe it seems, it quickly got divided a bit confusingly into different mixed groups of 80-or-so  male/female adults with at least 10 of each within each 20 age group (aka 20-40 years old, 40-60 years old, etc.). Each group was compared not only for age+gender, but also separately:

  • 1 group to compare a first trial of the stimulus to a second trial
  • 1 group to compare differences between each cracker type (brand)

Since all participants only self-reported the abscence of any history of swallowing or significant medical issues (no mention of respiratory concerns like asthma though🤔?), and ‘discrete bites’ sounds like something as vague as something familiarly seen in documentation (and anyone who knows me knows how big a a bite I take when you let me share something😂), there are still a couple things left to the clinical imagination.

saltineWhat I 😍LOVE😍 here–is that the authors didn’t use some fancy, specially made cracker designed for dysphagia, or a top-notch kitchen lab. Nope. They used what we all use–those dang Saltine crackers we find buried in kitchen/nutrition room drawers, crunched from getting stepped on, or in our scrub pockets at the end of the day completely broken😅!!  “The challenge in developing a test for solid bolus textures is in identifying a stimulus item that is available and consistent in size and viscosity worldwide…A cracker requires mastication but will generally mix with secretions in the oral cavity and remain cohesive.”

They even went so far as to weigh and compare the nutritional contents to Australia’s equivalent bedside snack, eventually coming to the conclusion that they are basically identical (though our dry “biscuit” does take the crumbly cake😎).

So what’s the difference between what they did in research and what we do as clinicians with our confused, sometimes dry-mouth, starving patient asking us for something to eat?

Well for starters, they had objective equipment:💁‍♀️😅

  • surface electromyography (sEMG)
  • acoustic/nasal airflow functions from Pentax Digital Swallowing Workstation

But before we might start with any 🙄eyerolls🙄 thinking yet again another research study that expects our facility to hand this equipment over to us, this is actually GOOD for us because it’s confirming what we actually do since they used the objective instrumental measures to compare to subjective observations guys! (a round of applause seems appropriate here👏👏)

Think they also gave explicit instructions while showing all the fancy feedback functions to the patient? Nope!

Their instructions were simple and clear throughout:

“Participants, seated comfortably, were asked to eat a single portion of the cracker ‘as quickly as is comfortably possible and when you have finished, say your name out loud’. They were advised not to talk during ingestion. However, speaking their name on completion of the entire cracker was used as a marker of task completion and oral cavity clearance.” p.147

Yes, even a simple stopwatch was used to time and things were counted as observed, real life folks!


Because there was a LOT going on, here’s how they broke the study projects up:


  • Participants ingested cracker twice in a session

Test-retest consistency

  • a trial and data were completed across 3 consecutive days (2 raters used once for interrater reliability)


  • Participants ingested cracker twice in a session; and twice in another session 4 hours later

But how did they know how long they were actually chewing?

Good question. . .

“Objective measurement of one masticatory cycle was determined by the point at which the sEMG amplitude for masseter activity was at maximum and for submental muscles was at minimum, followed by a reversal of these signals, indicating jaw closure and opening.” p.148

But how did they know when they actually swallowed?

Can’t get stumped on this one either!

“A swallowing event was denoted by the presence of swallowing apnoea in the
respiratory waveform, accompanied by a peak in the submental muscle sEMG activity. The acoustic signal was used as additional confirmation of swallowing; however, a strong acoustic signal was not clearly detected in all participants.” p.148badabingbadaboom

And a bonus: they basically measured the start time sEMG recorded initial movement for chewing up until the participant basically said there name (the acoustic signal for this was the bonus 😉 ).


Since there really is a lot of moving parts in this one well-thought-out study, here’s a quick run down of just what they were looking at and measuring:

  • # discrete bites
  • # masticatory cycles
  • # swallows per cracker
  • total time for ingestion/clearance
  • average number of masticatory cycles (# cycles / # discrete bites)
  • average number of swallows per bite (# swallows / # discrete bites)
  • average time per bite (# discrete bites / total time)
  • time per masticatory cycle (total time / # of masticatory cycles)
  • time per swallow ( total time / # swallows)

Just HOW did they get all that straightened out to find any results?

Basically, they used a way to analyze so many variables to see what popped up as significant. They also decided that if there were not any *significant* differences found between the 2 cracker stimuli, then everything else would be combined for the 2 crackers. But if there was a *significant* difference found, then each cracker would be looked at and analyzed individually.

Behind all the fancy mumbo-jumbo math, the authors really were just looking for ‘a difference‘ versus stating ‘this will be more/less than the other,’ then compared all the variables to see if there were any differences, and to see if age/gender had any correlation to each other for the variables.


babyyoda so much to learn

When everything was all said and done, some of the results were surpising, and others got me to barely blink an eye.

When it came to statistically comparing Australia’s cracker to our Saltine, “in general, the group ingesting the Salada cracker took more discrete bites, required more masticatory cycles and swallows, and more time to ingest the cracker than the group ingesting the Saltine cracker.

Before we go tossing anything and everything that isn’t a Saltine, the authors make sure to mention there were some inconsistencies for who got water and when for the 2 cracker trials. This inevitably could have an effect on the outcome since water could help mastication and movement better on the second trial (I feel like this is sometimes our clinical intuition to do, no?🤷‍♀️)

But not too fast! They soon realized that the same effect was also observed when participants had the other cracker twice in a session with water as well, so they chalked it up to the ingredients in the cracker versus the water.

“Regardless, normative data were reported for the first trial only for which liquid ingestion was not controlled. This is considered to represent a more realistic testing scenario in clinical practice.” p.154

Was the first trial better than the second trial??

“a tendency toward slower, less efficient performance on the second trial” p.149


Did it matter who was chewing the cracker??

While there was a signifcant difference on age and gender, one didn’t necessarily effect the other:

“However, none of the derived measures was significantly different as a function of age with the exception of number of swallows by time. Post-hoc analysis and evaluation of normative data suggest increased biomechanical movements and time associated with increased age.”

“male participants took fewer bites, chewed and swallowed less, and took a shorter amount of time than age equivalent females.” p.149

Now, if anyone wants to challenge this by challenging me to a pizza eating contest, I’m more than ready 😉 😂🤣🍕. (Now unfortunately I actually already feel myself eating more slowly as I get older! 🤭😅 )


Was what they found just a one-time thing, or did it happen again?

“The trial effect observed in the first study was also present in this analysis. The second trial consistently exhibited fewer masticatory cycles and swallows, as well as faster total time.” p.149



Soo, what would this look like in the hospital or skilled nursing facility??🤔🤔

We’re already carrying these crackers around with us, if anything for a nice quick snack.

I started to try to picture myself doing what they did in the study. Normally when I do this with research, other thoughts quickly intrude ‘Yeah right!‘  ‘There’s no way I could ever do this!’ Or asking to get specific equipment that was used in the research study is met with ‘In my dreams!‘  (of course it IS important to advocate for what you need though! 😉 ) However–with this, it actually looked an awful like what I’ve been doing this whole time. The only difference is, I’m actually observing, counting, and analyzing with a purpose and comparison versus going in blind and automatically labeling something “prolonged mastication😒.”

The best point from the article is not only what was found, but how. We don’t have to bring in some machine to tell us how many times a person is chewing, or strap someone up to see if it’s taking abnormally long. We can do what we do, use what we have, to still have an idea of what’s ok and what’s not.

“Finally, although clinical observation is required to count the number of bites, masticatory cycles and swallows, these observations are documented to be highly correlated with instrumental measures of the same behaviour. Thus, the measurements that are collected at bedside provide useful insight into a patient’s masticatory and swallowing ability without the need for instrumentation.” p.154

Now, if you’re planning on travelling to one of the other locations they used the rivalry cracker but all you’ve got are Saltine’s in your pocket, don’t worry, be happy! Because their methods were reproducible, you can conduct and compare with the wide range of crackers for normative data they provide for multiple continents😃.

Either way, the authors make note that it does matter who you are observing and timing, which is also similar to previous studies and the TWST the design was based off. boygirl


“Thus, when evaluating patients against the normative sample, attention should be paid to age and sex categorization.” p.154



How does can YOU use this article???

Do you use this in your assessment toolkit?!

What would this look like in your practice or facility?!?

Another question I pondered was, does this matter with IDDSI at all? (e.g. different chewing times for different ‘levels’ ??) For real, someone Instagram DM me @slprandr 😅

Do people have these norms, then carry out the ‘test’ ?

What measures do they look at? Do they have to use all of them, or just 1-2 easier ones to compare?

Should this be used and quantified to determine IDDSI solid levels??!?

Is this feasible?!? I’d LOVE to see that study!!! 😀




  • “The TOMASS was derived from procedures established by Hughes and Wiles (1996) for the TWST. As the TWST utilizes ingestion of a water bolus, the TOMASS was developed specifically to challenge ingestion of solid-bolus textures”
  • “Aspiration is known to occur more frequently with liquids than solid textures (Robbins et al. 1999) rendering this a more sensitive tool to this feature of swallowing pathophysiology.”
  • “Specific to bolus preparation, Van der Bilt et al. (2010) demonstrated significant differences between the masticatory patterns of old and young participants, resulting in larger particle sizes in boli manipulated by older individuals when compared with younger individuals after the same number of chewing cycles. This may reflect a decrease in the sEMG activity of masticatory muscles”


Article Referenced: [FREE ACCESS]

Huckabee, M.‐L., McIntosh, T., Fuller, L., Curry, M., Thomas, P., Walshe, M., McCague, E., Battel, I., Nogueira, D., Frank, U., van, den Engel‐Hoek, L. and Sella‐Weiss, O. (2018), The Test of Masticating and Swallowing Solids (TOMASS): reliability, validity and international normative data. International Journal of Language & Communication Disorders, 53: 144-156. doi:10.1111/1460-6984.12332


Click here for an extra TOMASS Handout, or checkout a Facebook Live Discussion on the topic from the Swallowing and Swallowing Disorders Journal Club!


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