An Example Of How The Tongue Affects The Craniofacial Shape

The tongue muscle is a group of muscles that work unlike any other muscle we have in our body. It has a free end and resembles the tentacles of an octopus. It is the most dynamic and strongest muscle in our head. We use it to speak, swallow, and breathe. We don’t survive as a species if we can’t swallow.

We know that proper swallowing mechanics promotes normal craniofacial development. Breastfeeding encourages proper tongue mechanics. A reverse swallowing mechanism (aka – tongue thrust) promotes a narrow, high palate and jaw that is often linked with bigger problems such as obstructive sleep apnea. Bottle-feeding and pacifiers encourage incorrect mechanics. I also believe many tongue ties can make proper tongue mechanics physically impossible.

Facial Shape Change From Mouth Breathing

Mouth breathers have a different facial shape. It is called an adenoid face. An adenoid face is where the face looks narrow side to side and long top to bottom. A study in monkeys showed that forcing them to mouth breathe by blocking their nasal passages, changed their shape into the adenoid pattern. Restoring nasal breathing restored the previous shape.

Oromyofunctional therapists promote a resting tongue posture at the roof of the mouth just behind the teeth. This is a correct posture that promotes nasal breathing and helps the hard palate develop normally. After having my first frenectomy, I mistakenly wrote in another post that I thought that left side was released more than the right.

Eventually I had two more frenectomies. One done in the same way as my first, that did not yield any further results. The most recent frenectomy was done in a different, deeper way. I no longer believe that the left side was released more, but that the right side of my tongue has always been more tethered than my left. I suspect it developed that way embryologically.

How The Tongue Is Affected

When I lift my tongue up away from the floor of my mouth, the right side gets pulled up where the left side does not as much. The left side of my jaw and floor of my mouth are more relaxed. When I put pressure on the floor of my mouth with my finger, the muscles are more sensitive and painful on right. Checking this on patients, I find that this is commonly the case.

The right side of the tongue being more strongly tethered changes the shape of the tongue. I noticed that my tongue looked different after my first lingual frenctomy. It was wider than before. It looked very different to me. The right side of the tongue is narrower than the left if you look at the picture. This is a result of the stronger tether on the right in my opinion.

How The Mandible Is Affected

I also believe as a result of the stronger tether on the right, the lower jaw develops more narrow on the right than the left. From the concept of mechanotransduction, we understand that cells communicate and respond through tensional forces. For example, we know that lip tension over the jaws affect their coming forward in development.

A stronger tether on one side pulls the mandible from the inside. This affects the lower jaw’s ability to develop wider and properly. But that’s not all. The lower jaw also develops in relation to the upper jaw to create a proper bite. The stronger tether physically makes the tongue’s ability to rest on the palate more difficult.

How It Creates A High Palate

In my case, I am unable to rest my tongue on the right side of my palate as effectively as I can on the left. There is a smaller surface area of contact on the right. So even when I rest my tongue with proper posture on the roof of my mouth, there is uneven contact.

The tongue resting on the roof of the mouth widens the palate. Those who do not rest their tongue on the palate, generally have a narrow high palate. In my case, my palate is higher on the right than the left. I don’t believe this is purely from tongue function in my case.

Since I’ve had a dental implant put in my right front tooth two decades ago, my facial structure has change and my teeth moved. What started out as a perfectly aligned tooth now looks markedly crooked.

The implant did not move, but my teeth around it did while attempting to maintain contact. However the teeth on either side collapsed some behind it. It makes my teeth look more like a thumb sucker’s tooth pattern. That collapse of the teeth behind the implant, also moves the upper jaw in a way that causes a higher arch on that side.

Notice in the picture how the teeth on the right side are angled downward more than the left. The implanted tooth is higher in the middle but the teeth further back are drawn downward in comparison to the left.

If you haven’t followed so far, you just need to understand that the tongue being more tethered on the right leads to a narrower lower and upper jaw. The narrower upper jaw has to adapt to the lost space by moving upward and creating a higher palate.

How A High Arch Lowers The Mandible On That Side

Most of the upper palate and jaw is formed by the maxillary bones. They make up a large portion of your face including the floor of your eye sockets. To create a high arch, a maxillary bone must rotate around an axis. Imagine a single line that goes from the front of your face and out the back through the bone.

The movement is not quite that simple, but this is what we’re using for educational purposes. For the palate to move up, the upper teeth need to move down with this rotational movement.

This places a torque on the mandible to adapt. So if you look at the picture, my right side of my mandible is lower than the left. The narrower upper jaw also creates a narrower face. Now, let’s talk about how this affects the eyes and potentially vision.

How Vision Can Be Affected

The asymmetry of the maxillary bones with respect to each other will change the orbit (the eye socket). So if the palate is higher on the right than left (like in my case), the eye will be higher on the right. So, looking at my face, it is possible to see that the right eye is not level with the eye.

Proper vision relies on the eyes being level. Generally, this imbalance will produce a tilt in the head and neck to level with the horizon and will produce an adaptive change throughout the body. At the same time the higher eye is generally also going to be drawn forward. You can see in the picture below how the right eye is forward in comparison to the left.

Again, this difference where the eyes are not level front to back can affect vision. The light enters one eye differently than it does the other and can affect visual acuity. The eyes are finely tuned organs.

Conclusion

The easiest way to explain this asymmetry is that the right side of the face is trying to be more of an adenoid face on the right whereas the left side is wider side to side and shorter top to bottom.

There are certain landmark’s that give you clues as to what may be happening when you study a person’s face. For example, when you look at someone else, you may notice some people have one eye higher than the other.

In those cases on the side that has the higher eye, you will commonly see:

• That same eye will be more forward
• The face will be narrower on the same side
• The jaw will be lower on the same side
• The ear less flared on the same side

You can infer that on the side of the higher eye:

• The arch of the palate is higher on the same side
• The tongue may be more tethered on the same side
• The arch and jaw will be narrower on the same side

There is so much more to this subject that I can’t cover it all here. All of this is just an exercise to understand how the tongue and it’s function is driving craniofacial development. Where it really becomes important is the long term effects of improper craniofacial development because of it’s health implications.

An underdeveloped jaw with a narrow, high palate is associated with major health problems related to airway (like obstructive sleep apnea) that we’re only beginning to understand. Full jaw development is a important for our health. This is because the tongue does not have the space it needs in the mouth if the jaw is underdeveloped. So it encroaches into the airway. It is a much more common problem than most of us realize. There are things that can be done, especially at early ages to prevent these problems in our future generations.