Mary is a 52-year-old woman who presented to our office complaining about daily pain in her jaws that would vary in intensity from day to day but was always present and impactful to her life. She’d been a patient in our practice ten years prior for a short period of time due to jaw tension and pain and periods of limited jaw opening.
Our treatment strategy at that time included an oral appliance to diminish the impact of her sleep bruxism, efforts to help her control her daytime jaw overuse behaviors, and the healing effects of time – all of which seemed to be sufficient to address her symptoms.
However, Mary was back in trouble with symptoms, and the strategies that were used years prior were not working this time around, including a new oral appliance made by her dentist. She stated that she’d been “suffering with miserable jaw pain” for the past eleven months.
Why Didn’t Mary Get Better? Consider These Three Types Of Pain
To explain why Mary didn’t get better, I invite you to consider the three types of pain that are common in the patients that are referred to our office. Though these are very distinct entities and can exist independently, they often co-exist – particularly when the initiating pain event was profoundly traumatic and/or perpetuating factors are not eliminated.
Recognition of which of the three types of pain is present ultimately determines the outcome of our treatment strategies:
1. Somatic Pain:
Somatic pain always occurs as a result of tissue injury or disease, such as in a muscle, joint, or tooth. It is called outside-in pain and is always associated with inflammation. The pain signals from the inflammation are carried by normally functioning nerves to the brain for interpretation.
The most common muscle and joint pains throughout the body are due to injuries and their associated inflammation. Most toothaches, for instance, are due to inflammation or a disease process in the dental pulp. When the source of injury or disease is removed, the pain typically resolves.
(For non-dentists reading this – dental pulp is the nerve tissue inside a tooth that is removed during a root canal procedure).
2. Neuropathic Pain:
Neuropathic Pain occurs due to abnormalities in nerve tissues. In these situations, pain arises from injury, disease, or dysfunction in the peripheral and central nervous systems. It is referred to as Inside-Out Pain.
In essence, Neuropathic Pain indicates a circuitry malfunction within the nervous system. The nerves become sensitized and have a lower firing threshold, similar to what’s experienced with a sunburn. As a result, pain can be experienced in a tooth despite the tooth structures appearing normal on x-rays and CT scans, for example.
Inside-out pain originates inside the nervous system itself, with an absence of tissue injury. Pain can be experienced in muscles and joints in a similar fashion in the absence of injury. Or, pain persists even though an acknowledged injury that had occurred months prior had healed. In summary, Neuropathic Pain indicates either a structural or functional abnormality in the peripheral or central nervous system has occurred. As a result, the typical therapies used to ease and/or solve Somatic Pain do not work.
3. Interpretive or Neuroplastic Pain: (also referred to as Dysfunctional or Central Mediated Pain)
This type of pain is strictly due to the brain’s interpretation of incoming signals.
All pain experiences are the result of the brain rendering an opinion, which is why injuries on the football field, for example, can occur in the first quarter. Yet, the player doesn’t experience pain until the game is over. So…there is no pain until the brain says so!
In fact, everything that’s happened in a person’s life has the potential to influence the brain’s opinion, whether it’s near or far from the alleged pain-prompting event. In these scenarios, when examined, the tissues where the pain is reported are normal, and the nerves conducting information to the brain are normal.
The origins of Interpretive/Neuroplastic Pain lie within the complicated interaction between the brain (pain perception and response) and the brainstem (pain sensitivity).
These three types of pain can certainly exist independently, but more often than not, when pain is persistent, the three co-exist – which makes solutions a lot more challenging.
Another Concept About Pain – Neuroimmune Interaction
Before I return to Mary, there’s another important concept to keep in mind when considering persistent pain – it may well be due to a Neuroimmune Interaction.
Over the past decade, research has shed light on the interaction between the immune and sensory nervous systems in initiating, maintaining, and potentially resolving persistent pain. Immune cells have been shown to directly and indirectly, regulate the sensitivity of the peripheral and central nervous system.
Think of it this way: the immune system (glial cells) is always on the lookout for signs of disease or cellular stress. For example, when identifying the presence of a virus in the body, glial cells send the information to the brain via nerve pathways.
This communication system prompts the release of pro-inflammatory cytokines in the brain, which results in fever, aches and pains, and the need to sleep and hydrate more. It’s how we know to stay home and take care of ourselves. When operating properly, the system works exceptionally well. However, glial cells are not always our friends. Sometimes they become “upset” and amplify the aches and pains throughout the body to a degree disproportionate to a disease process, insult, or even in the absence of local disease and/or injury. As a result, pain continues despite the tissue’s and peripheral nerves’ health.
But why can glial cells become upset and cause so much trouble?
There’s a multitude of reasons, including – but not limited to:
- Poor sleep
- Emotional distress
- Ongoing life stressors
- Persistent anxiety
- Nagging medical ailments
- Gastrointestinal dysfunction
- Medications that upregulate the autonomic nervous system
- Resurfacing of early life trauma memories
As you can see, there are plenty of reasons why pain can be a function of a neuroimmune relationship gone awry.
Back To Mary
When Mary returned to our practice, it was clear that direct treatment of her muscles and joints would not provide the relief she needed. Instead, we had to focus on the apparent neuropathic and interpretive components of her suffering.
So, what did we do?
In Part Two, I outline the treatment strategy we used to help Mary finally get better. I’ll also provide some insights into the benefits and limitations of BOTOX® and discuss some of the problems we’re seeing due to the wide range of healthcare providers who are using it for TMJ problems and bruxism.