Overbite: what it is, when it matters, and how it is treated

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1. What is an overbite?
2. What causes an overbite?
3. When does an overbite need treatment?
4. How an overbite is treated
5. How long overbite treatment takes
6. Risks of orthodontic treatment for an overbite
7. Keeping an overbite corrected after treatment
8. What affects the cost of overbite treatment
9. Having an overbite assessed in Woollahra or Mosman
10. Common questions

What is an overbite?

Your overbite is the amount your upper front teeth overlap your lower front teeth when you bite together, measured up and down. Orthodontics Australia, the public site of the Australian Society of Orthodontists, notes that a small amount of overlap is normal and gives 2 to 3 millimetres as a normal range.

It becomes a problem when the overlap is too deep. Orthodontics Australia defines a deep overbite as the top front teeth overlapping the bottom front teeth by more than one third. You will also hear it called a deep bite. In severe cases the lower front teeth can touch the gum on the inside of the upper front teeth.

	Overbite	Overjet
Direction	Vertical: how far the upper front teeth cover the lower ones	Horizontal: how far the upper front teeth sit in front of the lower ones
Normal range (Orthodontics Australia)	2 to 3 millimetres	1.5 to 2.5 millimetres
When it is too much	Deep overbite: more than a third of the lower front teeth covered	Upper front teeth protrude noticeably, sometimes called buck teeth
Main concerns if large	Wear on the front teeth and damage to the gums behind them	Front teeth more prone to chips, fractures and injury

How to tell if an overbite is deep

Bite together and look in a mirror. If your upper front teeth hide most of your lower front teeth, or you cannot see the lower teeth at all, the overlap is likely more than a third. That is only a rough guide: the depth and its cause are assessed properly at an examination.

Overbite and overjet are not the same thing

People often say overbite when they mean upper teeth that stick out. That is an overjet, and Orthodontics Australia points out that the two are often confused. An overjet is horizontal; an overbite is vertical. Some people have both, and the table below sets out the difference.

What causes an overbite?

Orthodontics Australia says the most common cause of an overbite is the position or size of the jaw or teeth. Its page on malocclusion adds that bite problems are usually inherited, and lists habits and events that can change how the jaws and teeth develop:

• Thumb sucking, and frequent dummy use after the age of three
• Teeth grinding (bruxism)
• Injuries that move the jaw out of line
• Teeth that are an unusual shape or impacted

Skeletal and dental deep bites

The cause shapes the treatment, so it helps to know the two broad kinds. A systematic review in Cureus in 2024 describes a skeletal deep bite as one that comes from the jaws themselves, typically in people with a shorter lower face and a lower jaw that has rotated forward, and often seen with a Class II division 2 bite. A dental deep bite comes from the teeth: front teeth that have erupted too far, or back teeth that have not erupted enough.

When does an overbite need treatment?

Not every overbite does. Orthodontics Australia notes that some people with a mild bite problem will not need any treatment, and that a pronounced overbite should be assessed when it causes difficulty chewing or speaking or other functional problems. Some people simply dislike how a deep bite looks, which is a fair reason to ask. Clinically, it is worth looking at when it is causing, or likely to cause, any of these:

• Wear on the front teeth. Orthodontics Australia notes that teeth that hit each other excessively can wear down the enamel and shorten the front teeth.
• Damage to the gum behind the upper front teeth. A systematic review published in 2012 notes that an extremely deep overbite can press on the palate and damage the gum on the inside of the upper incisors.
• Gum recession and loose teeth in severe cases, according to Orthodontics Australia.
• Jaw pain and headaches. Orthodontics Australia says a misaligned bite may contribute to them, though jaw pain has many possible causes.

How an overbite is treated

Orthodontics Australia says that for most people, overbite treatment means plates, braces or clear aligners. Orthodontically, a deep bite can be reduced in three ways, which the 2024 Cureus review sets out: bringing the back teeth up, moving the front teeth up into the gum, or tipping the front teeth forward. Which one suits you depends on whether the problem is in the teeth, the jaws or both. You can read more about how we treat overbites at our clinics on our service page.

Overbite treatment for children and teenagers

Orthodontics Australia notes that overbites tend to be easier to treat in children and teenagers because the jaw is still developing. Depending on the bite, a plan may use a removable or fixed plate with a bite plane behind the upper front teeth, braces, clear aligners, or in some cases headgear used alongside a bite plate. The Cureus review found the evidence too thin to say that any one of these approaches works better than another for growing patients. Our article on when a child should first see an orthodontist covers timing.

Overbite treatment for adults

Orthodontics Australia notes that overbite correction is also common for adults. Braces and clear aligners can correct many dental deep bites, but once the jaws have finished growing, a deep bite that comes mainly from the jaws may not be fully corrected by moving teeth alone. Our guide to orthodontic treatment as an adult covers what else changes.

When jaw surgery is part of the plan

Orthodontics Australia says that if an overbite comes from a malformed jaw, surgery may be required, with the orthodontist and surgeon working together. In that case we would refer you to an oral and maxillofacial surgeon and plan the orthodontic part alongside the surgery. We explain what treatment without surgery could and could not achieve before you decide anything. Some plans also involve removing teeth, which carries its own risks and is discussed in full first.

How long overbite treatment takes

Healthdirect says orthodontic treatment can take 18 months or more, with routine appointments every 4 to 12 weeks. Its guide to braces and retainers puts braces and aligners at 1 to 3 years. Your own timeline depends on how deep the bite is, whether the jaws are involved and how consistently you wear any removable appliance.

Risks of orthodontic treatment for an overbite

Orthodontic treatment is not risk free, and you should weigh the risks before deciding. The main ones are:

• Soreness. Healthdirect notes you may be uncomfortable for a couple of days after braces are fitted or adjusted. A clinical review in the Saudi Dental Journal reports that discomfort tends to peak on the second day and usually lasts about seven days.
• White marks and decay. Plaque left around brackets can decalcify the enamel, and the same review notes these lesions can develop within four weeks. A systematic review published in 2020 found they can still be seen up to five years after braces come off, so some marks may not fully fade.
• Root shortening. The Saudi Dental Journal review notes the risk of root resorption increases with the length of treatment.
• Ulcers and rubbing. Healthdirect lists scratches and mouth ulcers from braces rubbing, and gum infection.
• Relapse. Teeth can move again if a retainer is not worn as advised.

Keeping an overbite corrected after treatment

A deep bite can deepen again. The 2012 systematic review on the stability of deep bite correction found that most of the correction appears to hold over the long term, but its authors judged the evidence to be of low quality, and noted that how severe the bite was at the start seemed to be related to the long term result.

That is why retainers are part of the treatment. Healthdirect describes wearing a retainer for 12 to 24 months or longer after braces, and we explain which retainer suits you before treatment starts.

What affects the cost of overbite treatment

We cannot give a meaningful figure without examining your bite. Orthodontics Australia’s guide to costs lists what changes it:

• The type of treatment you need and the option you choose
• How long and how complex the treatment is
• Extra appliances the plan needs alongside braces
• Whether you have private health insurance extras cover

Having an overbite assessed in Woollahra or Mosman

You do not need a referral. Healthdirect confirms you can see an orthodontist without one, and notes that orthodontic treatment is not covered by Medicare, so check what your health fund includes. We set out the full cost before any treatment starts, and our page on spreading the cost explains how fees can be paid over time.

Prof. Ali Darendeliler and Dr Roshanak Boustan are specialist orthodontists, and Dr Eduardo Alcaino is a specialist paediatric dentist. If you are looking for an orthodontist in Sydney to check your bite, we see children and adults at 135 Edgecliff Road, Woollahra, and Suite 2, 600 Military Road, Mosman. Both clinics are on (02) 8412 0085.

Common questions

Is it normal to have an overbite?

Yes. A small overlap of the upper front teeth over the lower front teeth is normal. Orthodontics Australia gives 2 to 3 millimetres as a normal range. It is a deep overbite when the upper teeth cover more than a third of the lower front teeth.

What is the difference between an overbite and an overjet?

An overbite is vertical: how far the upper front teeth cover the lower ones. An overjet is horizontal: how far the upper front teeth sit in front of the lower ones. Teeth that stick out are an overjet, though people often call them an overbite.

Can thumb sucking cause an overbite?

It can add to one. Orthodontics Australia says bite problems are usually inherited, but lists thumb sucking and frequent dummy use after the age of three among the habits that can change how the jaws and teeth develop.

Can clear aligners fix an overbite?

They can treat many dental deep bites, but not every one. Which appliance suits you depends on the cause and severity of the bite and on how consistently you would wear removable aligners, and that is decided at an assessment.

Does every deep overbite need surgery?

No. Orthodontics Australia says surgery may be required when an overbite comes from a malformed jaw. It also says that for most people treatment means plates, braces or clear aligners. Whether yours can be treated without surgery depends on its cause and severity, and we will explain the options.

Will my overbite come back after treatment?

It can. A 2012 systematic review found most deep bite correction appears to hold long term, on low quality evidence. Wearing your retainer as advised is the main way to keep the result.

Do I need a referral to have an overbite checked?

No. Healthdirect confirms you can see an orthodontist without a referral from your dentist.