Many people have crowded or crooked teeth, or their teeth do not meet correctly when they bite. These problems can mean it's harder to keep your teeth and gums clean and your teeth are more likely to become damaged.
In some cases, abnormal positioning of your teeth and jaw can affect the shape of your face.
Orthodontic treatment is usually only started after most of a child's adult teeth have started to come through.
This is usually when they're about 12 years old but it depends on how many of their adult teeth have come through and the growth of their face and jaws.
Orthodontic treatment for adults can begin at any age, but the treatment options are more limited.
The length of treatment will depend on how complicated the problem is, but it's usually between 18 and 24 months.
When treatment finishes, you will need to wear a retaining brace. This is usually removable and needs to be worn every night to keep your teeth in their new position. They're usually used for at least 12 months, but your orthodontist will advise you. Sometimes a thin wire may be permanently fixed behind your teeth to keep them in place.
Clear aligners are an alternative to traditional braces and are designed to help guide teeth into their proper position. Similar to braces, clear aligners use a gradual force to control tooth movement, but without metal wires or brackets. The aligners are made of a strong plastic material and are fabricated to fit each individual's mouth. If a series of aligners are needed, each aligner moves the teeth in incraments until the desired movement is achieved.
Aligners are worn for at least 20 hours a day to reach the desired maximum effectiveness. Each aligner is worn for three weeks before changing to the next one. The length of treatment with aligners depends upon the severity of each case. Typically, aligner treatment can be as short as three weeks or as long as six months. Overall, aligners offer a much shorter treatment than traditional braces.
Fixed braces are the most common type of orthodontic appliance.
A few days after a fixed brace is fitted you'll be able to eat a normal range of foods. But you should avoid certain foods and drinks, such as toffee, hard sweets and fizzy drinks, as these can damage the appliance and your teeth.
If you're using a fixed appliance and you play a contact sport such as rugby, you should wear a gum shield to protect both your mouth and the appliance.
Fixed braces are usually made from metal, so they will be noticeable on the front of your teeth.
Usually plastic plates that cover the roof of the mouth and clip on to some teeth; these can only be used to achieve very limited tooth movements
Removable braces can be used to correct minor problems, or as part of fixed-brace treatment.
They can also sometimes be used to discourage children from sucking their thumb