Biomechanics vs. The Underbite

Can Reviv solve an Underbite? If so, why and how?

Lots of folks ask me whether Reviv addresses an underbite or an overbite.

Some of these folks ask me whether they should do surgery.

I always immediately respond with a “No!” to that one.

And so I thought i’d address the underbite (class 3) today and i’ll address the overbite (class 2) in a future article.

What is a class 3 bite (underbite)?

Basically it is when the lower teeth are positioned forward in relation to the upper teeth.

Like you see in the above pic of Jay Leo who famously has a class 3 bite.

Sylvester Stallone is another one.

Dentists believe this happens because the lower jaw (mandible) is either disproportionately large, the upper jaw (maxilla) is too small, or a combination of both.

I don’t think that is the whole story and i’ll explain more.

Some context on my own experience

In the past decade i’ve wavered between a class 1 and a class 3 bite numerous times. For most of the time I have been edge-to-edge and I am still edge-to-edge now.

I pay almost no attention to this and don’t think it is a good thing to focus on.

The only time I became class III was when I did experiments where i’d essentially locked the jaw in the wrong position and messed up the soft tissue. Something i did a fair bit during my early years (2015-17).

In the end, however, i do think pretty much everyone ends in a class I bite when they’ve fixed everything.

And i generally think people are almost never truly skeletally class III. But i also haven’t researched the topic that deep and so i say that with an asterisk.

When I took this ‘to the end’ around 2016 I remember that I was class I again and my jaw had kind of popped forward when the soft tissue of my jaw broke and shed.

It led me to the conclusion that this class III bite is almost completely a function of soft tissue and is almost never skeletal.

Class III bite a function of soft tissue?

So when I say it is a function of soft tissue what do i mean? Let me explain a bit more.

To understand this a bit more I highly encourage you to play with a model of a skull sometime. I have one in my house that looks like the one in the pic above.

The kind with the jaw that is attached by a spring is the best. Because you can open the jaw and move it around a bit. Twist it, hold it open, hold it forward in class 3, etc.

When you do this it locks in your mind that the jaw is truly a completely separate bone that is only connected by soft tissue to the rest of the skull and can move in three planes like a plane.

And whether you are class 1 or class 3 is a function of many factors. Not just the size of your jaw or your skull, but also what is going on in the neck. Because if you change the angle of the skull on the neck then this can also move you between class 1 and 3.

So basically the way i view it is there are all these different things going on in the skull, the neck and the jaw which are then cemented in a specific position by the soft tissue that covers it all.

So if you want to change their relative position in order that your bite goes from class 3 to class 1 you need to stretch the soft tissue so that these different pieces can move. In other words you need to ‘inflate’ the skull as i often talk about.

Example of OSB Method

My son is an example of my thesis

My son had an edge to edge bite when we tried OSB (Soulet Besombes) method on him with a dentist in Moscow in late 2018.

It’s a method in which you put composite over all of the teeth (like in the pic above) and lock a different occlusion. It seemed aligned with what i was thinking at the time (note that I didn’t fully figure out the puzzle till late 2021) and so i did it to not just myself but also my 4-year old son who was a heavy mouthbreather at the time.

He was sleeping really poorly and so I was pretty desperate to do something that would get him sleeping ok so that his development wouldn’t negatively be impacted.

Anyway the OSB ended up being a disaster for both me and him. We immediately got cavities and it was clearly not the answer. So we got all of the composite taken off in 2019 and he had an open posterior bite for awhile.

This ended up putting him in a mild class 3 bite, which he more or less maintained for the next year or two.

Then in late 2021 we had flat composite put just on his last lower tooth on either side. And he’s been improving ever since. I also have him wear a rubber mouthguard as much as possible, but he doesn’t like to sleep with it.

By late 2024 he was back in a class 1 bite and his arches had grown a lot. He had nice healthy gaps between his teeth and many other health things had improved including his spine.

So essentially by using my biomechanical principles of adding height and using a non-locking occlusion we’d taken him from class 3 to class 1 and fixed everything.

He’s going to be a beautiful, healthy adult one day and probably never have to worry about any of this shit. Score one for papa ;)

Closing thoughts

Dentists are going to claim all kinds of things when it comes to why people have a class 3 bite and how to fix it.

Many of them are going to say I’m wrong. And I really don’t care.

This game has taught me one thing… I trust my own judgment over all of them.

Why? Is it just blind, stupid faith?

No. It’s because I understand how this soft tissue works better then any dentist or guru i’ve seen out there.

I’ve seen how it stretches and how this affects the skull, the spine and occlusion. I’ve seen it on my own body & skull by experimenting with it for a DECADE.

And from what i’ve seen thus far i’m pretty sure the simple biomechanics of wearing a rubber mouthguard consistently will fix a class III bite given enough time.

Just keep it simple and be patient.

And watch all of those who try to force things with orthodontics or surgery crash and burn in the end.

I’ve been watching that shit for a decade now. It never ends well ;)