The Jaw Dysfunction Hypothesis
I have a long history of both jaw dysfunction and orofacially-triggered misophonia. I am triggered by both myself and others, and the vast majority of my triggers can be directly linked to some form of jaw dysfunction.
My visual and kinaesthetic triggers include:
Downswung maxillae
Deep bite
Narrow upper jaws
Set-back or retruded lower jaws
All of these are textbook indicators of jaw underdevelopment, as defined by Mike Mew.
My auditory triggers include:
Tongue-popping—the sound the tongue makes when it quickly releases from being suctioned to the back of the mouth/epiglottis (suggests insufficient tongue space)
Snorting when laughing (associated with tissue obstructing the airway around the back of the nose)
Breathing (a well-functioning respiratory system is generally silent at rest)
Extreme snorting/throat clearing (general dysfunction)
Some word pronunciations, vowel sounds, and general speech sounds that are affected by the above aspects of jaw dysfunction
In combination with recent research indicating the involvement of orofacial mirror neurons in misophonia, these factors lead me to wonder whether there is a direct causal relationship between jaw dysfunction and misophonia.
Explanatory power
Misophonia requires an explanation. In the absence of any evidence that we should have evolved to be misophonic by default, there must be some specific pathology behind it. The JDH would provide such a pathology in the form of jaw dysfunction.
There are two phenomena we know to exist: A) an evolutionarily novel epidemic of jaw dysfunction that begins in childhood and causes serious issues throughout the body; and B) a reasonably prevalent emotional disorder that generally begins in childhood, is assumed to be in need of an explanation, and that we’ve just discovered is linked to orofacial motor neuron mirroring.
Open Questions
There are a number of potentially contradictory facts that would have to be explained for the jaw dysfunction hypothesis to be true. They include:
Non-orofacial triggers
Many sufferers are triggered by seemingly unrelated stimuli such as leg swinging and pen clicking. For leg swinging I would put forward the possibility that body movements such as these “get to” our misophonic reflex via whole-body mirroring and the fact that jaw dysfunction causes whole-body posture issues. The core issue is that we are somehow “trapped” inside our underdeveloped maxillae, and that feeling of constriction and claustrophobia is what drives the fight or flight response. A misophonic trigger is any stimulus that makes us acutely aware of our restrictedness.
For pen clicking I would simply suggest either that non-orofacial sounds can be similar enough to orofacial sounds to remind us of them and “get the wheels in motion”, or that there is some hidden link between these types of motor activities and the orofacial muscles. (Such a link doesn’t seem to be out of the question when you consider, for example, the tendency to stick one’s tongue out when performing intricate tasks with the hands.)
Coincidence
When you start looking at things as though they’re connected, and when they’re as complex and interconnected as the brain and body to begin with, it’s bound to be the case that more connections start appearing. I haven’t found any evidence yet to rule out the possibility that jaw dysfunction and misophonia are just two phenomena with a lot of overlapping aspects.
Conclusion
Obviously I am biased by my own experiences with misophonia and jaw dysfunction. But given the general prevalence of jaw-related triggers, the prevalence of jaw dysfunction, the well-established ability of jaw dysfunction to affect multiple bodily systems—including the ears—and the recent findings on orofacial mirror neurons, it seems clear that jaw dysfunction warrants investigation.