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TMJ & MCAS – a different perspective

Since the start of October, maven Tracey Reed has been sharing with us her story to choosing elective jaw surgery. Her hope is to solve the root piece of what may be triggering her Mast Cell Activation Syndrome. Go through previous blogs to catch up if you're just reading this first one today.


I recently came across another possible connection.

A couple of months ago I had registered for a Vagus Nerve Connection summit. Truth be told, I register for a lot of these summits, but rarely watch the talks. Instead, I scan the topics and presenter of the day, and decide if there is information that will be new and relevant to me.

My time is precious, and I want to use it efficiently, so all research I do has to be focused and specific to histamine or mast cell mediated concerns. So, here I am, a couple of months away from jaw surgery and I see the title Jaw Misalignment, Substance P and Vagal Tone. I was in!

The talk was given by a dentist, Dwight Jennings, DDS. For over 4 decades, his practice has focused on the influence of bite on overall health. His practice is specifically focused on oro-facial pain and TMJ treatment.

So I watched the talk, took a few notes, and then had to set them aside because I was busy with clients and getting my daughter organized and moved with furniture and all the household items needed for an apartment for her to start university. Very exciting times, but too busy to think about Substance P.

But now I’m revisiting those notes I took, so that I can squeeze the writing of this blog article in before I get my surgery, so that we can post it as part of this series. And so that you will have something educational and inspirational (I hope) to read while I am bedridden and recovering. Though Luka will also have you covered while I’m incapacitated.

Substance P - what is it?

Let me begin by telling you what Substance P is.

Substance P (image to the left here) is a neuropeptide that acts as a neurotransmitter and a neuro-modulator. Think of it as a signalling chemical.

As a signalling chemical, it communicates information to neurons and other cells in the body. It is best known for its role in pain perception.

Sound familiar? What kind of pain are you struggling with?

Pain and the Histamine and Mast Cell Connection

It has a lot in common with histamine, which can also act as a neurotransmitter. Both Substance P and histamine are needed in the body for very important functions such as vasodilation. In excess though, they are problematic.

Both can bind to receptors on mast cells and activate mast cells. As a signalling molecule, Substance P communicates or “talks” to other cells by binding to receptors. It binds to G protein-coupled receptors in mast cells. With this action, now degranulation is induced.

Luka and I talk a lot about how neuropeptides “cross talk” with mast cells resulting in mast cell sensitization when we do presentations to various groups. We have also written about it this in A Battle of Nerves.

Knowing the significance of “cross talk”, I knew I needed to watch a talk with Jaw Misalignment and Substance P in its title.

In the context of MCAS

I want to make it clear that I am not rehashing Dr. Jennings’ talk in this blog, but rather putting it into the context of MCAS. You can find all kinds of podcasts and Youtube videos of Dr. Jennings if you want to know more about TMJ problems and Substance P. It’s super cool stuff!

The key thing I learned from his talk is the role of Substance P in TMJ pain. Research supports the idea that people with TMJ problems have enhanced pain sensitivity.

Put that together with the fact that Substance P activates mast cells and it makes sense that the ongoing sensitization of mast cells from TMJ related Substance P could be a contributing factor to MCAS.

My Theory (from last week’s post):

My theory overlapping Dwight Jennings’ discussion with MCAS:

When I did a bit of a deeper dive into the research, I discovered that these two pathways might be more similar than at first glance. It turns out that stress and anxiety are correlated to Substance P and that blocking Substance P transmission can reduce the stress response.

If I overlap that information into my theory and the information from Dwight Jennings, then I get this:

This also explains one of the pathways on how emotional stress impacts MCAS. But that is a discussion for another day.

Suffice it to say that Substance P can be triggered via multiple factors, and that it triggers mast cell activation. Is it a contributing factor to MCAS?

What do you think? Yes or no?


Since the start of October, Tracey has been sharing her journey as she is in line to undergo jaw surgery in an attempt to reduce the strain on her mast cells, contributing to her diagnosis of Mast Cell Activation Syndrome. Her surgery has now been postponed to the new year. You can follow Tracey’s journey here on the blog, as well as on Instagram and Facebook where she'll be posting regular check-ins and updates along the way.

Is the information shared here resonating with you? Might we recommend you join us in our free Online Community. We share lots of downloadable resources, information, recipes. There's even a master class to help you make that Histamine Connection. Click here to access this free community!

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