Why Are My Teeth Shifting as an Adult? What Stops It
Clinically reviewed by Dr. Abinaash Kaur, DDS, RCDSO, on 2026-10-19. Dr. Kaur is a general dentist in Toronto (Bloor West Village) registered with the Royal College of Dental Surgeons of Ontario.
Yes, adult teeth keep shifting all through life, whether or not you ever wore braces. A common version is the lower front teeth slowly crowding over the adult years, which is usually normal ageing, while new gaps, a tooth that tips, or a bite that suddenly feels different point to gum disease, a missing tooth or wear from grinding and deserve a look.
I hear some version of "my bottom teeth moved" in the chair all the time. It usually comes from someone who never had braces and wants to know what they did wrong.
Usually nothing.
The Ontario Dental Association puts it plainly: "Your teeth can move throughout your life after orthodontic treatment due to many factors" (Ontario Dental Association). Teeth move without any treatment at all, too. Here's what's normal, what isn't, and what slows it down.
Most people blame their wisdom teeth. What does the evidence show?
Most people think their wisdom teeth are pushing everything forward. The research mostly doesn't back that up.
The best test is a randomized trial in people who'd already had braces. Crowding of the lower front teeth rose by 2.1 mm on average when the wisdom teeth stayed, and removal cut that by 1.1 mm, a difference the authors called neither statistically nor clinically significant (British Journal of Orthodontics via PubMed).
Their conclusion was that removing wisdom teeth to prevent late crowding "cannot be justified."
A Cochrane review found only one trial on whether removing wisdom teeth changes the dental arch, in people who had already had braces. That trial found no evidence that removing symptom-free impacted wisdom teeth has a clinically significant effect on the arch, but it was at high risk of bias, and the review says the evidence isn't enough to decide whether those teeth should come out (Cochrane Database of Systematic Reviews via PubMed).
A 2023 review of 10 studies agreed. The vast majority found no significant link between wisdom teeth and crowding coming back after braces, though "a minor effect has been suggested" (Dentistry Journal via PubMed).
So wisdom teeth aren't proven innocent. They're not the main suspect.
Something at the back of the mouth does seem to creep forward, though. In a small study of teenagers, comparing 21 whose lower front teeth crowded with 21 whose teeth didn't, the crowding group showed significantly greater forward movement of the second molar (British Journal of Orthodontics via PubMed). That points to the back teeth drifting forward, though it doesn't settle whether a wisdom tooth plays a part.
Wisdom teeth can still cause real trouble. The ODA says a wisdom tooth without enough room can become impacted (stuck under the gum or bone) and cause pain, infection, and damage to neighbouring teeth (Ontario Dental Association). That's damage next door, not front crowding. Our post on when wisdom teeth need to come out covers those cases.
Why do the bottom front teeth crowd as you get older?
Late lower crowding is the slow overlapping of the bottom front teeth after the teen years. It's widely regarded as "a normal maturation event which is likely to affect most individuals to some extent," and it's often mistaken for braces relapsing (Annals of the Academy of Medicine, Singapore via PubMed).
Long-term studies of adults who never had braces show the same thing.
- Swedish dentists followed for decades. Eighteen dentists with no braces were measured again after an average of 38.4 years. Lower front crowding rose by 1.0 mm, and the distance between the canines narrowed by 0.8 mm on top and 1.0 mm on the bottom (European Journal of Orthodontics via PubMed). The authors called it "a continuous process throughout adult life." It's a small group, so read it as a pattern.
- Adults from 25 to 46. Thirty people with untreated, normal bites lost room for their teeth, and the authors called these changes "part of the normal maturational process" (Angle Orthodontist via PubMed).
- Right here in Toronto. The Burlington Growth Research Project at the University of Toronto, the faculty where I trained, followed untreated parents and children for roughly 30 to 34 years. Lower front crowding kept increasing in every group, and the arches kept getting a little shorter and narrower with age (American Journal of Orthodontics and Dentofacial Orthopedics via PubMed).
When is shifting a warning sign?
Slow crowding of the bottom front teeth is one thing. New gaps, a front tooth fanning outward, or a bite that feels different are another.
Gum disease is a bacterial infection of the gums, ligaments and bone that support the teeth and hold them to the jaw (Ontario Dental Association). The Government of Canada says bone loss can occur, deep pockets can form between the teeth and gums, and teeth may eventually loosen (Government of Canada). It also says the damage usually can't be reversed.
Teeth that drift because of gum disease have a name: pathologic tooth migration. Bone loss appears to be a major factor in it (Journal of Periodontology via PubMed).
It's common. In one study of 343 people with moderate to severe gum disease, 30.03% had front teeth that had drifted, as reported by the patients (Journal of Periodontology via PubMed).
Among 44 of those patients studied in more detail, most had more than one kind of movement: front teeth flaring outward (90.9%), gaps (88.6%), rotation (72.7%), and a tooth rising out of line (68.2%) (Journal of Periodontology via PubMed). Across studies, the share of gum disease patients with drifting teeth ranges from 30.03% to 55.8% (Journal of Periodontology via PubMed).
The ODA's warning signs for gum disease include gums pulling away from the teeth, "Loose or separating teeth," and "A change in the way your teeth fit together when you bite" (Ontario Dental Association).
To check, a small measuring instrument goes between the tooth and gum to measure pocket depth, and X-rays may be taken to look at the bone (Ontario Dental Association). The measuring matters because gum disease often progresses slowly with no pain (Ontario Dental Association).
A new gap isn't always a lost cause. In early cases, teeth that have drifted sometimes move back on their own after the gum disease is treated (Journal of Periodontology via PubMed). Sometimes, not always. Our post on gingivitis versus periodontitis explains when gum disease reaches the bone.
What does a missing tooth do to its neighbours?
A gap can change over time. The ODA says that after a tooth is lost, other teeth "may start to shift or over-erupt to compensate." It adds that after an extraction, apart from a wisdom tooth, other teeth may shift, and that teeth should be replaced partly "to prevent other teeth from shifting" (Ontario Dental Association).
Over-eruption means the opposing tooth slowly grows toward the empty space. In a study of 100 patients and 100 controls, unopposed back teeth over-erupted by an average of 1.68 mm, compared with 0.24 mm in controls, and it showed up in 92% of the unopposed teeth (Journal of Prosthodontics via PubMed).
The teeth on either side move too. A companion study found the tooth in front of the gap tends to tip toward it, and tipping of the tooth behind the gap can be extreme (Journal of Prosthodontics via PubMed). The ODA adds that changes in tooth position can make teeth harder to clean and raise the risk of gum disease and cavities (Ontario Dental Association).
If you're weighing how to fill a space, our dental bridge vs implant guide walks through how waiting changes the options.
Can grinding, pregnancy or menopause move teeth?
Grinding first. The ODA says untreated grinding can lead to "cracked, chipped, broken or loose teeth" (Ontario Dental Association). A systematic review of six studies suggested that grinding "cannot cause periodontal damage per se," meaning it doesn't damage the supporting bone by itself, though the research is thin (Journal of Periodontology via PubMed).
In my experience, grinding is a wear-and-crack problem first, and a bigger worry when the bone is already reduced. Our post on how to stop grinding your teeth at night covers what helps.
Pregnancy changes the gums. The Canadian Dental Association says hormonal changes can make gums more sensitive and raise the risk of pregnancy gingivitis, which causes swelling and bleeding (Canadian Dental Association). The ODA puts that risk in the second to eighth month (Ontario Dental Association).
Whether female hormones loosen teeth has rarely been studied. One small study of 50 women found no change in tooth mobility across the menstrual cycle (Journal of Indian Society of Periodontology via PubMed). So if your teeth feel different after a baby, the gums are what I check first. More in our post on pregnancy and dental health.
Menopause changes the mouth too. The ODA's list for menopause is taste changes, a burning feeling, sensitivity to hot and cold, and dry mouth (Ontario Dental Association). The bone and gum disease side of that story is in our post on perimenopause and your mouth.
None of the association pages I read links pregnancy or menopause to tooth movement.
What stops teeth from shifting?
You can't stop teeth from changing over a lifetime. You can deal with the causes that speed it up, and hold a result you like.
Try this:
- Get the gums checked. Damage from gum disease usually can't be reversed, so catching it early matters (Government of Canada).
- Talk to your dentist about replacing a missing tooth (a missing wisdom tooth is the usual exception) before its neighbours lean into the space.
- Protect your teeth if you grind. Our post on night guards explains the options.
- Wear your retainer after any straightening. The ODA's position is that retainers "must be worn throughout the duration of a person's lifespan" (Ontario Dental Association). I put it more plainly: wear it for as long as you want the result. Our retainer guide covers the rest.
The ODA explains that braces work by gentle pressure, which moves teeth over months or years (Ontario Dental Association). I looked at how far that pressure idea goes in does mewing work.
We offer braces or clear aligners, and Invisalign is one clear aligner option we can talk through at a consult.
In about 25 years in Bloor West Village, I've watched plenty of bottom teeth drift a little over years of checkups, and often the right answer is to keep an eye on it.
Some days the schedule pushes me, and even then we take the time you need.
Frequently Asked Questions
Q: Is it normal for teeth to shift in your 30s and 40s? Pretty much, yes. Some crowding of the lower front teeth is widely regarded as a normal maturation event likely to affect most people to some extent (Annals of the Academy of Medicine, Singapore via PubMed), and a University of Toronto study following untreated people for roughly 30 to 34 years found that crowding kept increasing with age (American Journal of Orthodontics and Dentofacial Orthopedics via PubMed). New gaps, loose teeth or a changed bite aren't part of that normal pattern and need an exam.
Q: Do wisdom teeth cause crowding? The evidence doesn't show a clear link. A randomized trial in people who'd had braces concluded that removing wisdom teeth to prevent late front crowding "cannot be justified" (British Journal of Orthodontics via PubMed), and a 2023 review found mostly no significant association, though "a minor effect has been suggested" (Dentistry Journal via PubMed).
Q: Why are my teeth shifting even with a retainer? Part of it may be ordinary change over time rather than relapse. In a 12-year study of 92 treated patients, about 25 per cent of the tooth displacements seen years later didn't exist before treatment, which the authors read as "usual growth changes and not relapse" (European Journal of Orthodontics via PubMed). A retainer that no longer fits or isn't worn as prescribed is the other common reason, covered in our retainer guide.
Q: Can teeth shift after an extraction? Yes. The ODA says other teeth may shift or over-erupt after a tooth is lost, apart from a wisdom tooth (Ontario Dental Association). In one study, an unopposed back tooth over-erupted by an average of 1.68 mm, and it happened in 92% of unopposed teeth (Journal of Prosthodontics via PubMed).
Q: Can gum disease make teeth move? Yes. Bone loss from gum disease can leave teeth loose (Government of Canada), and 30.03% of people with moderate to severe gum disease in one study had front teeth that had drifted, most often flaring outward or opening gaps (Journal of Periodontology via PubMed).
Q: How do you stop teeth from shifting with age? Treat the causes you can: gum disease, missing teeth and grinding. After any straightening, the ODA's position is that retainers must be worn throughout a person's lifespan, and it notes teeth can be moved at any age if crowding bothers you (Ontario Dental Association).
Reviewed by Dr. Abinaash Kaur, B.Sc., DDS (University of Toronto Faculty of Dentistry), who has practised general and family dentistry in Bloor West Village for about 25 years. This article is general oral health information, not a diagnosis or a substitute for an examination.
Noticing your teeth moving, a new gap, or a bite that feels different? Come in and we'll check your gums and your bite. We're at 750 Annette Street in Bloor West Village, serving the Junction, High Park, and Baby Point. Book a visit with The Village Dentist, or ask about a clear aligner consult if the crowding bothers you.
