Crowded teeth: why there is no room and why it matters
People most often arrive saying “my lower teeth have somehow shifted, they used to be straight”. Sometimes they add that it started after thirty, or after the wisdom teeth came through. The phrase “teeth went crooked” is inaccurate: teeth do not bend on their own, they change position when they run out of room. And before talking about appearance, it is worth understanding what that crowding does to the gums and the enamel.
Why teeth run out of room
Crowding is arithmetic. The combined width of all the teeth exceeds the length of the arch they have to fit into. The difference may be two millimetres or ten.
Where it comes from.
Heredity. The commonest cause. Tooth size comes from one parent, jaw size from the other. Large teeth on a small jaw, and there is not enough room from the start.
Early loss of baby teeth. A baby tooth holds space for the permanent one. If it is removed long before its time and no space maintainer is placed, the neighbouring teeth drift into the gap and the permanent tooth has nowhere to come through. That is why an orthodontic check before school is not a formality.
Mouth breathing and childhood habits. A permanently open mouth changes tongue position, and the tongue shapes the width of the upper jaw from inside. Prolonged thumb or dummy sucking belongs here too.
Age-related change. More on that below.
And here is what is not on the list: wisdom teeth. That is the commonest myth, and it deserves unpacking.
Why lower incisors shift after thirty
This is a distinct phenomenon with a name — late lower incisor crowding. It is noticed by people whose teeth were straight in their youth.
For a long time it was blamed on wisdom teeth: they came through and “pushed” the arch forward. Current evidence does not support that version — crowding develops just the same in people who had their wisdom teeth removed at twenty.
The real causes are more complex and act together.
Natural narrowing of the arch with age. The lower jaw keeps changing slowly throughout life, and the arch gradually becomes narrower at the front.
Wear on contact surfaces. Teeth rub against each other while chewing, become narrower where they touch and drift forwards to compensate.
Pressure from soft tissue. The lip and cheeks press inwards for a lifetime.
Loss of support. If a back tooth was extracted and never replaced, its neighbours tip into the gap and the geometry of the whole arch changes.
The practical conclusion: if you once wore braces and stopped using your retainer, that is the second and principal reason your teeth “went back”.
What it leads to beyond appearance
This is the important part, and the one least often discussed.
Decay between the teeth. In a crowded arch the contact surfaces overlap and floss simply will not go in. Plaque stays there for months. Decay on a side surface is invisible from outside and painless for a long time — it is found once it has already reached the dentine. Often on two neighbouring teeth at once.
Gum inflammation and calculus. In tight areas the brush does not reach the gum margin. Plaque mineralises, calculus forms and the gums become inflamed. Over the years this progresses to periodontitis — which means bone loss around the roots, and that is irreversible.
Uneven wear. A tooth standing at an angle takes chewing load on the wrong surface. Enamel wears faster, sensitivity appears, sometimes chips.
Gum recession. A tooth pushed beyond the bony plate gradually exposes its root. No amount of brushing fixes that; it needs separate surgery.
Harder prosthetic work later. When a crown or implant is eventually needed, there may not be room for it, and orthodontic preparation will have to be done anyway — only under pressure of circumstance.
None of this means everyone needs treatment urgently. Mild crowding with impeccable hygiene can go years without causing trouble. But the risk is worth assessing before the first filling appears between two teeth.
How severity is assessed
An orthodontist does not say “a bit crooked” — the space deficit is measured in millimetres.
Up to 4 mm — mild. One or two teeth protrude or are rotated. Hygiene is still possible, if effortful.
4–8 mm — moderate. Several teeth are noticeably displaced and there are places floss will not enter at all.
Over 8 mm — pronounced. Teeth stand in two rows, some are fully out of the arch.
Measuring it requires imaging, models or a scan, and a photographic record. Only then is it clear how much space is missing and where to take it from — and that is where the question of extraction is decided.
The assessment is done at a consultation: a CT scan of both jaws costs UAH 1,290, an orthodontic consultation UAH 690.
What is done about it
The method depends on severity, not on preference.
Mild crowding. Aligners handle it well and discreetly. Sometimes stripping alone is enough — removing 0.2–0.5 mm of enamel from the side surfaces.
Moderate. Here the choice is real: braces or aligners, with arch expansion or distalisation of the back teeth. The difference between systems is covered in the article braces or aligners.
Pronounced. Usually braces, often with premolar extraction. Aligners are less predictable over that amount of movement.
Timelines run from 12 months for mild crowding to 24–30 for pronounced cases. More on timelines in a separate article.
Prices: braces from UAH 15,900 per jaw (metal ligature), aligners from UAH 99,000 for the full course. Monobank instalments are available — three payments with no mark-up.
And separately, what not to do. Putting veneers on crowded teeth to “straighten them visually” is a decision that costs dearly later: to seat a veneer on a tooth standing at an angle, far more of it has to be ground away, sometimes down to the nerve. Orthodontics first, aesthetics second — in that order the tooth stays alive.
Frequently asked questions
Why do teeth crowd with age?
The dental arch naturally narrows at the front, contact surfaces wear down, and the lips and cheeks press inwards for a lifetime. If you once had braces, the main reason is usually that you stopped wearing your retainer.
Are wisdom teeth to blame for lower teeth shifting?
Current evidence does not support that. Late crowding develops just the same in people who had their wisdom teeth out at twenty. The causes are different and act together.
Why is crowding harmful beyond appearance?
Floss will not go between crowded teeth, so decay develops there and stays painless for a long time. Calculus builds up in tight areas and the gums become inflamed. Add uneven enamel wear and the risk of exposed roots.
Could good hygiene be enough instead of treatment?
With mild crowding and impeccable care, sometimes yes, for years. But the risk is worth assessing in advance, not after the first filling between two teeth.
Can crowding resolve on its own?
No. The jaw will not gain space, and soft tissue pressure is constant. Without treatment the situation slowly worsens.
Which is faster for crowding: braces or aligners?
The timeline is set by the amount of movement, not the system. For mild crowding aligners are more comfortable; for pronounced crowding braces are more predictable.
Could veneers replace straightening?
Technically yes, but a tooth at an angle has to be ground down much further, sometimes to the nerve. The right order is orthodontics first, aesthetics second.
From what age can crowding be treated in a child?
It depends on the cause. Sometimes intervention comes early, to widen the jaw while the palatal suture is open; sometimes the change of dentition is awaited. A first check is worth doing before school.
What does the assessment cost?
An orthodontic consultation is UAH 690 and includes an examination and a plan. A CT scan of both jaws for precise measurement costs UAH 1,290.
Orthodontic treatment for children and adults: brace systems, aligners, bite correction. Modern protocols, thorough diagnostics and individual planning at every stage.
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The orthodontist will measure exactly how many millimetres are missing and show the options — with and without extraction. A consultation costs UAH 690.
Or book by phone 067 478 88 78
Find out your own space deficit
The orthodontist will measure exactly how many millimetres are missing and show the options — with and without extraction. A consultation costs UAH 690.
Book now