• Teeth which do not sit properly can lead to a variety of problems, including tooth decay and gum disease.
  • Orthodontics is a type of dentistry that corrects teeth and jaw alignment problems.
  • Speak to your oral health professional if you are worried about how your or your child’s teeth sit.
The teeth of the upper and lower jaw should fit neatly together. When they don’t, it can increase the risk of tooth decay and gum disease. Orthodontics is an area of dentistry that diagnoses and corrects teeth and jaw alignment problems using devices such as braces and plates.

When orthodontic treatment might be needed

Crooked, crowded and overlapping teeth can cause a range of problems, including: 

  • tooth decay and gum disease – teeth that are very close together can be harder to clean properly. A build-up of plaque can lead to tooth decay and gum disease
  • injury to the gum – if a tooth doesn’t meet with its partner on the opposite jaw properly, it may dig into the gum and cause damage
  • wear and tear – if teeth don’t sit properly the action of chewing can wear them unevenly
  • self-confidence – teeth problems can make people feel embarrassed and they may not feel comfortable to smile.

Diagnosis of teeth and jaw alignment problems

Problems with teeth and jaw alignment are identified using a number of tests, such as: 

  • x-rays of the mouth
  • impressions of the upper and lower jaws, which are used to make plaster casts.

Examples of orthodontic problems

Some common orthodontic problems are: 

  • excessive overbite – is when the top teeth bite over the bottom teeth more than normal. With teeth closed, you would normally expect to see about half of the lower teeth. If you see less than half, this could be an excessive overbite
  • underbite – the bottom jaw sits further forward than normal. When teeth are closed, the lower front teeth sit in front of the upper front teeth.
  • protruded teeth –when the upper jaw sits further forward than the lower jaw. With the teeth together, you would expect the upper teeth to sit on the inside of the lower lip. If they sit over the lower lip, this might be a sign of protruded teeth. A person with protruded teeth is more at risk of tooth damage or loss from accidents and may have speech or eating problems. Many people also choose to correct protruded teeth for cosmetic reasons.
  • crowded teeth – there is not enough space for teeth to sit side by side and they overlap. Can be caused by large teeth, a small jaw, or both.

Examples of orthodontic treatments

A range of orthodontic devices may be used to move teeth, or to keep them in place. These include: 

  • braces – tiny brackets are attached to the front of each tooth, and a wire is tied to them. The constant gentle pressure of the wire slowly moves the teeth
  • clear aligners – also known as ‘invisible braces’, clear aligners are clear pieces of custom-moulded plastic that sit over the teeth and gradually move them. While you usually need to wear clear aligners for 20–22 hours a day, you are able to take them out to eat, drink and clean them
  • elastics – these small rubber bands are stretched between upper and lower braces for extra force to move teeth
  • plate – a plastic device that sits in the mouth and uses wires and springs to push teeth into a particular position, or to hold them in place. Unlike braces, a plate can be taken out of the mouth.

Age for orthodontic treatment

Usually, teeth problems that may benefit from orthodontic treatment can be detected by eight or nine years of age. Most orthodontic treatment is done after all the permanent teeth have come through, at around 11 to 13 years. Some treatment can be started earlier, at about age eight or nine. Adults can be treated too.

Risks of orthodontic treatment

Some of the risks of orthodontic treatment include: 

  • dental hygiene problems – braces and wires make cleaning the teeth more difficult. This may increase the chance of tooth decay and permanent marks. It is important that teeth are cleaned thoroughly twice a day during orthodontic treatment to avoid these problems
  • soft tissue injury – braces may dig into the gums or cheeks, damaging them
  • relapse – the corrected teeth may move again once braces are taken off. The main reason plates are worn after braces have been taken off is to prevent this from happening.

Orthodontic treatment 

Orthodontic treatment is provided by an orthodontist, and sometimes by a dentist. An orthodontist is a dentist who has done additional study to specialise in the diagnosis, prevention and treatment of problems in the alignment of teeth and jaws. 

The orthodontist or dentist will take detailed records of your teeth and jaw, diagnose any problem, plan the treatment and carry out the care as required.

Costs vary depending on the type of problem and the amount of treatment needed. Ask your orthodontist or other oral health professional for advice.

Where to get help

More information

Mouth and teeth

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This page has been produced in consultation with and approved by: Dental Health Services Victoria

Last updated: February 2018

Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your doctor or other registered health professional. Content has been prepared for Victorian residents and wider Australian audiences, and was accurate at the time of publication. Readers should note that, over time, currency and completeness of the information may change. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions.