If teeth are mounted in sockets in the jaw bone, how do braces move them around? Do the sockets move with them?

Submitted by MyCodesCumpie-ling t3_11h5lgf in askscience

If teeth were sort of free-floating in the gum tissue I could understand how braces move them to the desired position. But if they are mounted in solid bone sockets, how can braces still move them? Does the bone ahead of the movement 'part' and the bone behind close in? Or does the old socket stay in place and just grow bigger in the direction of the tooth's movement? Is this connected at all to why many need retainers after having braces removed?

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MildElevation t1_jau2imx wrote

Teeth are anchored by the periodontal ligament. The pressure exerted by the braces on the tooth is sensed by mechanoreceptors within the periodontal ligament, signaling osteoclasts to alleviate the pressure on the alveolar bone by breaking it down locally. The bone is then restructured around the tooth when the pressure has subsided.

Retainers hold the teeth in place afterwards and avoid movement caused by things like healing tissue, elastic action of the periodontal ligament, or occlusion (how your teeth contact with biting/chewing).

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big65 t1_jauadfq wrote

So this is like breaking and rebuilding of the bone?

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Cluefuljewel t1_jaun6xf wrote

Bone is not totally rigid like cement is. It has a little bit of flexibility. This feature is very important for our survival.

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Toothbinch t1_javsoyn wrote

Bone is constantly being broken down and remade so that it can adapt to the forces we put on it with our muscles and it doesn’t get too brittle

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Tym370 t1_jazqgli wrote

So then how does a root canal affect the tooth/jaw relationship?

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Toothbinch t1_jb0e942 wrote

The root canal won’t affect the tooth/jaw relationship.

A root canal takes out the nerve via the hole that it sits in in the center of the tooth and running down the center of the roots. It is then replaced with an anti-bacterial rubber substance and closed up with a filling and most of the time a crown/cap as well.

Outside of the root there are those little periodontal ligaments that attach the tooth to the bone, and those are still alive after a root canal. Think of them as strings and when we get braces/chew/put force on the strings it tightens them on one side of the tooth and loosens them on the other. Where the right strings are, the body knows to lay down more bone because the current bone needs to be stronger to stand up to all the force, but where the loose strings are the body knows to get rid of some bones because it’s being essentially useless in this area where it’s not taking much of any forces. The body is doing its best to adapt to the pushes and pulls that is put on it. This is true of all bones- if you work out a certain muscle the corresponding bone will get stronger/denser in the places it interacts with that muscle.

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drillnfill t1_jaup267 wrote

As well your jaw never really stops growing, it just slows down a lot, as well as joint degeneration and remodeling results in the mandibular (lower) front teeth being forced against the upper front teeth, and usually the lowers buckling resulting in the lower crowding you see (especially in men as they tend to show lower teeth a lot more than women) in older males. I'm looking at you Will Ferrell. Retainers keep the teeth in the same relative position as the bone moves around them

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[deleted] t1_jav4xe1 wrote

Does this mean I can finally stop wearing my retainer after 15 years?

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tnew12 t1_javl4vr wrote

If you want your teeth to be where they are, absolutely not. You signed up for a life of retainers

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Toothbinch t1_javskec wrote

Dentist here. Depends on how your teeth were before you got your braces. If they had massive spacing and rotation, then they will likely slowly go back to what they were. It’s so variable person to person that we always say wear your retainer nightly for life

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Mountaingiraffe t1_jaw48x2 wrote

Just a bit off topic, but how do you view the mostly cosmetic reasons to get retainers at like 16 years old? Those things hurt enormously as a kid, and being too young to really have an informed say on things. Everyone also had them back 20 years ago.

I had a talk with someone and they remarked that you could see them as a form of child abuse if done just for cosmetics. (I had a little overbite and the orthodontist said it could wear away the back of my upper front teeth eventually)

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Toothbinch t1_jawc935 wrote

What you’re describing sounds more like someone trying to prevent wear with a retainer as a guard more than actually used as a retainer. Not abuse and can be really important to protecting your teeth. Wear is more than just cosmetic when it’s a chronic thing that happens for a long time

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darrellg_ t1_jazodka wrote

Would you mind answering the real question he asked about how prevalent it was about 20 years ago and used as a cosmetic device for developing children? If not it is fine. I just wonder how the practice has changed in time.

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MoonieNine t1_jaw8zt0 wrote

DON'T stop wearing your retainers. Wear them at least 3 or 4 night a week. I stopped wearing mine after my puppy got a hold of them, and figured my teeth were fine. My teeth then shifted SO GRADUALLY that I didn't really notice until a year later when I REALLY looked at my teeth and the damage was done. They're not horrible, but they're definitely not straight like they were, and my one side tooth bugs me now. I had new retainers made and wear them at least 3 nights a week and always will.

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Speed_Alarming t1_javyjy1 wrote

You can stop any time. It will stop doing its job around the same time.

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lucidrage t1_jaw3uwu wrote

If you're close to retirement age then you might as well. When do teeth start to fall out?

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[deleted] t1_jaw42z3 wrote

Huh. I thought it was just that bone is living matter and will grow and change with the pressures exherted on it, including pressure from teeth and chewing.

What I said about bone is true, but it looks like it's more complicated than just that.

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