Does / can mouth breathing cause lower jaw surgery regression?

[murgy]

Does / can mouth breathing cause lower jaw surgery regression?

[Mark32]

That's something I've asked in another thread. It's something that concerns me as I've long wondered if mouth breathing contributed to the misalignment in the growth of my jaws in the first place. Ages back someone on the forum explained that mouth breathing is thought to lead to undergrowth of the upper jaw and overgrowth of the lower - but I think he said that it has never been proved.

I think I've read on here that you can't counteract soft tissue forces when moving around the bones in your jaws. My worry is that if doing something 'abnormal' with some of the muscular forces in my mouth produced 'abnormal' jaw growth won't my jaw eventually be remodelled somewhat back into that misaligned shape/position after surgery if nothing changes to that muscular imbalance.

[Mark32]

I definitely think that I've experienced excessive vertical growth due to mouth breathing. I actually think I used to mouth breath as child throughout the day as well and not just at night. I remember being teased at school for always going around with an open mouth at around age 12/13. I then made a conscious effort to close my mouth which was really difficult, and I think that may have been because I was having to get used to only nasal breathing. However, as I now realise the habit continued at night.

One thing that I've always noticed about my bite that puzzled me - and probably is only explained by too much vertical growth - is how long my crowns are (they all seem to have over erupted) without there being any vertical overlap between my upper and lower incisors. It's like the vertical gap/height between my upper and lower jaw - especially at the anterior end - has been increased in two ways: longish teeth and no incisor overlap. I must have an open bite tendency. It's funny but when my adult teeth came through as a child they always looked overly large in photographs where I was smiling.

Does excess vertical growth do any to diminish the prominence of your chin? You know, in the opposite way to how some people with a collapsed bite/short lower face have very jutting chins. It's just that I have a flattish chin - if that makes sense - and I've noticed that people with a longish lower face and a class III tendency often lack chin projection.

[molestrip]

A retrognathic profile diminishes chin prominence so yes. When you rotate the lower jaw forward, the chin advances relative to the lower lip. Teeth would over erupt if you had an open bite.

How long is your face btw? I'm told mine is 17 degrees and normal is 8 degrees. It doesn't sound too terrible to me. I don't recall mouth breathing until middle or high school. I also started bruxing then and wore a mouth guard, preventing normal tongue posture. Combined with tongue thrusting from OSA, my bite stood no chance. It seems like most of my deformity came from late stage growth.

[terry947]

@ molestrop - how long is your face? mines around 8-8.5ish. Also what do you mean by 17 degrees? the angle of the maxilla?