Orthodontics is the branch of dentistry that corrects teeth and jaws that are positioned improperly. Crooked teeth and teeth that do not fit together correctly are harder to keep clean, are at risk of being lost early due to tooth decay and periodontal disease, and cause extra stress on the chewing muscles.

If you have any of the following, you may be a candidate for orthodontic treatment:

• Overbite, sometimes called “buck teeth” – where the upper front teeth lie too far forward over the lower teeth
• Underbite – a “bulldog” appearance where the lower teeth are too far forward or the upper teeth too far back
• Crossbite – when the upper teeth do not come down slightly in front of the lower teeth when biting together normally
• Open bite – space between the biting surfaces of the front and/or side teeth when the back teeth bite together
• Misplaced midline – when the centre of your upper front teeth does not line up with the centre of your lower front teeth
• Spacing – gaps, or spaces, between the teeth as a result of missing teeth or teeth that do not “fill up” the mouth
• Crowding – when there are too many teeth for the dental ridge to accommodate

The severity of your problem will determine which orthodontic approach is likely to be the most effective. There are many kinds of fixed and removable orthodontic appliances. They place gentle pressure on the teeth and jaws.

The length of treatment will depend on how complicated the problem is, but it’s usually between 18 and 24 months.

A common complication of orthodontics is tooth decay. Many people with appliances find it difficult to keep their teeth clean, so extra brushing is essential during treatment.

There are four main types of appliances:

fixed braces – a non-removable brace made up of brackets that are glued to each tooth and linked with wires

removable braces – usually plastic plates that cover the roof of the mouth and clip on to some teeth; they can only carry out very limited tooth movements

functional appliances – a pair of removable plastic braces that are joined together or designed to interact together, and fit on to the upper and lower teeth

headgear – this isn’t an orthodontic appliance itself, but can be used with other appliances and is usually worn at night