Did you know that mouth-breathing can cause a lifetime of TMJ pain
In the previous blogs we went over what happens when the tongue drops in order to allow mouth breathing. That causes the buccinator muscle to have unopposed pressure and results in a narrow upper arch. But here is the real problem long-term. When the tongue drops to get air in when mouth breathing, it can cause forward pressure on the front upper teeth causing overjet. BUT, sometimes, the tongue will cover the posterior teeth instead, and that causes another issue. When the tongue covers the posterior teeth when it drops, this leads to over-eruption of the lower front teeth since that’s what teeth do - they erupt until there is something opposing them. So as the front teeth erupt, and the back teeth are prevented from further eruption, that causes a problem when biting down.
Typically when we bite down we want to have equal even forces across all our teeth. But if the lower front teeth erupt while the back teeth don’t, as the person closes, the front teeth hit first. Now the muscles don’t like that; the muscles want all teeth to touch. So what the muscles of mastication do is the figure out how to get the back teeth to touch - they slide the jaw back until that happens. So sure, now the back teeth are touching, but the jaw is too far back. As this person continues to do this over and over, that causes the TMJ disc, the cartilage that is supposed to insulate and protect the jaw joint, to slip off causing a click or a pop. As that happens over time, the person begins to have all kinds of other TMD (Temporo-mandibular Disorder) symptoms like jaw pain, ear pain, muscle pain, headaches, neck pain. Now the jaw pain is obvious, right? As the jaw goes back into the skull and ear when the muscles slide it back to get the back teeth to touch, we can see why that would hurt AND cause ear issues. I mean the jaw is not supposed to push into the ear. But why the neck?
Well, here is what happens over time. As the jaw goes back over and over and over again, it begins to block the airway, preventing that air that is supposed to now come in through the mouth in the first place. So what does the body do to get more air in? It opens the airway. How? By pushing the jaw forward through a head shift forward. So now you get the head to come forward and the airway opens. So all good? NOPE. That’s why the neck and subsequently the shoulders hurt. Because now they have to balance the head in the forward position. WHAT ?
Ok, basic physics. The retruded mandible causes airway obstruction so to open airway, the head moves forward. Normal head weighs about ten pounds. But force is measured at the fulcrum which is at the base of the head where it’s being held in the first place. The force at the fulcrum is equal to weight times distance. So the weight of the head times the distance AWAY from the fulcrum. As the head comes forward, the distance increases, and that results in more force being felt at the fulcrum. The neck muscles must balance that weight so they strain in order to hold the now 40-pound head in position.
So people with retruded mandibles often have neck and shoulder pain. And until you fix that, massage or other therapy can work briefly but won’t work long-term. Only when the bite is corrected, will this person finally feel relief and pain resolution.