Crooked teeth: why they become misaligned, what the risks are and how to correct them (at any age).

Do you have crooked teeth and wonder why they’ve moved? We’ll explain the real causes (in children and adults), the implications for your health, and the treatments available: braces, clear aligners and veneers. Find out which one’s right for you.
Picture of Doctor Vicente Platón
Doctor Vicente Platón
Doctor en Odontología (mención sobresaliente cum laude). Especialista en Periodoncia e Implantes. Licenciado en Odontología, Universitat Internacional de Catalunya. Master en Periodoncia e Implantes, Universitat Internacional de Catalunya acreditado por la European Federation of Periodontology (EFP). Post-Grado en Prostodoncia, Universitat Internacional de Catalunya. Master en Biomedicina, Universitat Internacional de Catalunya. Profesor Asociado del Master de Periodoncia de la UIC. Socio titular especialista de la sociedad española de periodoncia y osteointegración (SEPA).

Table of Contents

There is a widespread belief that crooked teeth are ‘a child’s problem’ – something that is sorted out with braces during adolescence and then forgotten about for good. The reality is quite different: millions of adults have misaligned teeth, and many of them had straight teeth when they were younger.

Teeth are not set in cement. They are attached to the bone by an elastic ligament (the periodontal ligament) which allows for constant micro-movements. Over the course of a lifetime, forces such as pressure from wisdom teeth, bruxism, bone loss due to gum disease or simply the natural movement of the teeth can gradually shift them millimetre by millimetre, until one day you look in the mirror and think: “Has it always been like this?”.

In this article, we’ll explain why teeth become crooked (in both children and adults), what real consequences this has beyond aesthetics, and the treatment options available today: from traditional braces to invisible orthodontics and dental veneers. We’ve included indicative prices so you can get an idea of the costs before your consultation.

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Why do teeth become crooked? The 6 real causes

There is no single reason. In most cases, it is a combination of genetic and environmental factors that build up over the years:

Genetics
Children and adults
The size of the jaw, the shape of the teeth and bite patterns are inherited. If your parents had an overbite, it is likely that you do too.
Childhood habits
Children (0–6 years)
Thumb-sucking, prolonged use of a dummy or bottle beyond the age of 2–3 years. These can distort the palate and push the upper teeth outwards.
Premature loss of milk teeth
Children (3–12 years)
If a milk tooth is lost prematurely (due to tooth decay or an impact), the neighbouring teeth shift and close the space for the permanent tooth, which then comes through crooked or impacted.
Wisdom teeth
Young adults (17–25)
When they erupt without sufficient space, they push the other teeth forwards. This is the most common cause of crowding of the lower incisors in adults who previously had straight teeth.
Periodontal disease
Adults (aged 35+)
Periodontitis destroys the bone that supports the teeth. Without support, the teeth shift, tilt and gaps appear where there were none before.
Failure to wear a retainer after orthodontic treatment
Any age
One of the most frustrating reasons: patients who wore braces as teenagers and stopped using their retainer. Teeth have a ‘memory’ and will start to shift again.
Picture of a person with crooked teeth

Crooked teeth are not just a cosmetic issue

Many patients come to the clinic saying, ‘I don’t like them, but they don’t bother me’. And it is true that slightly misaligned teeth are not a medical emergency. But it is worth noting that dental crowding has functional consequences that go beyond what you can see in the mirror:

Crooked teeth are not just a cosmetic issue
1

Increased risk of tooth decay

Crowded teeth create nooks and crannies that a toothbrush cannot reach and where dental floss cannot get in. Plaque builds up and tooth decay occurs precisely in these hard-to-reach areas.

2

Gum disease

Where plaque accumulates, the gums become inflamed. Chronic crowding promotes gingivitis and, if left untreated, can lead to periodontitis.

3

Uneven wear

If the teeth do not mesh correctly, some bear more of the load than others. This causes accelerated wear, fractures and sensitivity in specific teeth.

4

Joint problems (TMJ)

An unbalanced bite can put excessive strain on the temporomandibular joint, causing jaw pain, clicking, headaches and neck pain.

5

Self-esteem and social life

Not being able to smile with confidence affects personal and professional relationships, as well as one’s self-image. It is just as valid a reason for seeking treatment as any other.

Picture of a person with crooked teeth

Cómo corregir los dientes torcidos: las 3 opciones reales

Cuando se trata de alinear dientes, solo hay tres caminos legítimos. Cada uno tiene su indicación, sus ventajas y sus limitaciones:

Braces
Metal, Ceramic or Lingual

The most versatile treatment. Suitable for everything from mild cases to complex malocclusions. Ceramic and lingual braces offer a more discreet appearance.

CasesMild to severe
Duration12–24 months
ResultActually moves teeth
Invisible Orthodontics
Clear Aligners

Removable, nearly invisible aligners that are replaced every 1–2 weeks. Ideal for adults. They do not interfere with eating habits or oral hygiene.

CasesMild to moderate
Duration6–18 months
ResultActually moves teeth
Dental Veneers
Porcelain or Composite

Thin shells bonded to the tooth surface. They can change shape, size and colour. Suitable only for minor misalignments or as a complement after orthodontic treatment.

CasesMinor / Cosmetic only
Treatment Duration2–3 appointments
ResultConceals, does not move teeth

Braces or clear aligners? How to choose

This is the million-dollar question for any adult with crooked teeth. The honest answer is: it depends on the individual case, not on the appearance of the appliance. Both systems actually move the teeth, but they are suitable for different situations.

Choose clear aligners if: your misalignment is mild to moderate, you value discretion, you have the discipline to wear the aligners for 22 hours a day, and you don’t have complex bite problems (severe open bite, skeletal crossbite).

Choose braces if: your case is complex (severe crowding, bite problems, teeth rotated by more than 30–40°), you need maximum control over tooth movement, or you prefer a treatment that ‘works on its own’ without relying on your consistency in wearing the aligners.

There is a third, increasingly common scenario: combining orthodontics with veneers. First, the teeth are correctly aligned using orthodontics, and then veneers are fitted to perfect their shape, size and colour. This is the approach that offers the most spectacular aesthetic results, but it is also the most expensive.

Guía Integral para Corregir Dientes Torcidos y Desalineados
Guía Integral para Corregir Dientes Torcidos y Desalineados

Crooked teeth in children: when to seek treatment

If your child has crooked milk teeth, don’t worry. Milk teeth often have gaps or slight rotations that correct themselves when the permanent teeth come through. However, there are signs that do warrant a visit to the orthodontist:

  • Premature loss of milk teeth (due to tooth decay or an impact) before the age of 10–11.
  • Crossbite (the lower teeth bite over the outside of the upper teeth).
  • Thumb-sucking or tongue-thrusting beyond the age of 3–4 years.
  • A very narrow palate or chronic mouth breathing (breathing only through the mouth).

The Spanish Society of Orthodontics recommends an initial assessment at 6 years of age. At this age, with the first permanent molars and incisors having already erupted, the orthodontist can detect problems with space or bite and, if necessary, intervene with interceptive orthodontics (simple appliances that make use of the child’s growth to correct the root cause of the problem).

Picture of a person with crooked teeth

In short: it’s never too late to straighten crooked teeth

Whether you’re a teenager with obvious crowding or a 50-year-old adult who’s noticed that your front teeth have started to shift, there’s a solution and it’s more accessible than ever. Modern orthodontics is faster, more comfortable and more discreet than it was a generation ago.

The important thing is not to take shortcuts. Be wary of miracle cures found online, home-made braces and promises of straight teeth in a matter of weeks. A professional diagnosis will tell you exactly what type of treatment you need, how long it will take and how much it will cost. And from there, the decision is yours.

Frequently Asked Questions
Why do teeth become crooked in adulthood?
The most common causes are the eruption of wisdom teeth (which push the front teeth), periodontal disease (bone loss allows the teeth to shift), failure to wear a retainer following previous orthodontic treatment, and bruxism (clenching and grinding generate forces that move the teeth over time).
Can crooked teeth be corrected without orthodontic treatment?
In cases of mild and purely cosmetic misalignment, dental veneers can conceal the misalignment without moving the tooth. However, if there is a functional bite problem or moderate to severe crowding, orthodontic treatment is the only option that actually corrects the position. Veneers are not recommended for severely crooked teeth.
Do crooked milk teeth mean that the permanent teeth will be crooked too?
Not necessarily. Crooked baby teeth or teeth with gaps do not reliably predict the position of the permanent teeth. However, if there is an obvious lack of space or habits such as thumb-sucking, an orthodontic assessment is advisable from the age of 6 to intercept problems in good time.
Can teeth be straightened at home?
No. Attempting to move teeth using elastic bands, homemade braces or internet ‘tips’ is extremely dangerous. It can lead to tooth loss and damage to the roots and bone. Tooth movement requires controlled forces, monitored by a professionally trained orthodontist.
How much does it cost to straighten teeth?
It depends on the treatment and its complexity: metal braces range from 1,500 to 3,500 EUR; aesthetic braces (ceramic/sapphire) from 2,500 to 4,500 EUR; invisible orthodontics from 2,000 to 5,500 EUR; and veneers (for mild cases only) from 250 to 600 EUR per tooth. Most clinics offer finance plans.
I only have one crooked tooth. Do I need full orthodontic treatment?
Not always. If there is only one misaligned tooth and your bite is correct, there are options such as partial orthodontics (braces or aligners on just one arch), or even a veneer if the misalignment is minimal and purely cosmetic. Your orthodontist will assess which option is most appropriate.
Can veneers be fitted if the teeth are very crooked?
It is not recommended. Veneers correct minor aesthetic flaws (shape, colour, slight rotations), but they do not move the teeth. If the misalignment is severe, fitting veneers straight away would require grinding away too much healthy tooth structure, and the result would look unnatural. The ideal approach: orthodontic treatment first, followed by veneers if you wish to further improve the appearance.
Is it too late to correct crooked teeth as an adult?
No. Orthodontic treatment works at any age. The difference is that in adults, treatment may take slightly longer (the bone is denser) and it is more likely that any pre-existing periodontal problems will need to be treated before starting. But the end result is just as good.