What is the best treatment for children with crowded teeth?

When teeth erupt (come through the gum into the mouth), they may twist, stick out, drop back, or overlap if there is not enough space in the mouth. Losing baby teeth early from tooth decay or trauma can lead to crowded permanent teeth. If crowded teeth affect a child’s self‐esteem or cause pain, damage or chewing problems, the child may be referred to a specialist dentist known as an orthodontist to correct them. Crowded teeth can be prevented or corrected using braces if crowding is mild (less than 4 mm). Removal of some teeth (extraction) may also be needed if crowding is moderate (4 to 8 mm) or severe (more than 8 mm). Fixed braces are used on permanent teeth. Removable braces can be used on baby or permanent teeth, or both. Baby or permanent teeth can be extracted.

Are braces effective for treating crossbite (top back teeth biting down inside the bottom back teeth)?

Posterior crossbite occurs when the top teeth or jaw are narrower than the bottom teeth. It can happen on one side or both sides of the dental arches. This condition may increase the likelihood of dental problems (e.g. tooth wear), abnormal development of the jaws, joint problems, and unbalanced facial appearance. Posterior crossbites affect around 4% and 17% of children and adolescents in Europe and America. 

Different treatment approaches have been proposed, resulting in many different braces being produced. The basic treatment to correct crossbite correction treatment involves using an orthodontic device on the palate (roof of the mouth) to expand the upper jaw by exerting pressure on both sides of the jaw. The devices can be fixed (e.g. quad‐helix, Haas, Hyrax expander) or removable (e.g. expansion plate). Fixed appliances are bonded to the teeth, while removable devices can be taken out of the mouth by patients.

Fluorides for preventing early tooth decay during fixed brace treatment

Wearing a fixed brace makes it harder for people to keep their teeth clean and may also cause pain. Pain can make it more difficult for people to brush their teeth. This can lead to a build-up of dental plaque around the brackets that attach the fixed brace to the teeth. If the plaque stays on the tooth for long enough, it will cause early tooth decay, which looks like white or brown marks (demineralised lesions, also known as white spot lesions). People often wear braces for 18 months or longer and if the decay is left to progress, it can cause holes, which are sometimes bad enough to need fillings to be done in the teeth.

Fluoride helps the tooth to heal, reducing tooth decay in people who are at risk of developing it. People receiving fixed brace treatment may be given different forms of fluoride treatment. It is important to think about how the fluoride gets to the teeth. Does the fluoride need to be placed by a dentist or dental nurse, or can people having treatment with braces apply the fluoride to their own teeth?

Which material works best for the first arch wire in a fixed brace?

Orthodontic treatment is undertaken worldwide to correct crowded, twisted, buried or prominent front teeth. This treatment is normally given in adolescence or adulthood. Fixed orthodontic appliances, otherwise known as braces, consist of brackets bonded to the teeth. The brackets are connected by arch wires, which exert forces on the teeth to straighten them. The first, or initial, type of arch wire, inserted at the beginning of treatment, is for correcting crowded and twisted teeth. Over recent years, a number of new materials have been developed, which show a range of different properties in the laboratory and which manufacturers claim offer benefits in terms of tooth alignment. These include mixtures of nickel and titanium (NiTi).

Early-phase treatment of prominent upper front teeth in children may have benefits

Prominent (or sticking out) upper front teeth are a common problem in children around the world. For example, this condition affects about a quarter of 12-year-old children in the UK. The correction of this condition is one of the most common treatments performed by orthodontists (dentists who specialise in the growth, function and position of teeth and jaws). This condition develops when the child’s permanent teeth erupt. Children are often referred to an orthodontist, for treatment with dental braces, to reduce the prominence of the teeth. Prominent upper front teeth are more likely to be injured and their appearance can cause significant distress. If a child is referred at a young age, the orthodontist is faced with the dilemma of whether to treat the patient early or to wait until the child is older and provide treatment in adolescence.

In ‘early treatment’, treatment is given in two phases: first at an early age (seven to 11 years old) and again in adolescence (around 12 to 16 years old). In ‘late treatment’ (one phase), there is only one course of treatment in adolescence.

As well as the timing of treatment, this review also looked at the different types of braces used: removable, fixed, functional, or head-braces.

How effective are painkillers in reducing the discomfort caused by orthodontic treatment?

Pain is a common side effect of orthodontic treatment. The pain resulting from orthodontic treatment may differ depending on the amount of force applied and the type of braces used. It may also change over the first few days following treatment. Pain has been ranked as the worst aspect of treatment and is the most common reason for people wanting to discontinue orthodontic treatment. Painkillers, swallowed or applied directly to the sore areas of the mouth following treatment, are thought to relieve the pain, making brace treatment more comfortable and acceptable. These painkillers are often cheap, readily available, easy to use and do not cause serious side effects.

No evidence from RCTs on effectiveness of orthodontic treatment for deep bite and retroclined teeth

Orthodontics is concerned with growth of the jaws and face, development of the teeth, and the way teeth and jaws bite together. Ideally, the lower front teeth bite in the middle of the back surface of the upper front teeth. When the lower front teeth bite further behind the upper front teeth than ideal, this is known as a Class II malocclusion. A Class II division 2 malocclusion is characterised by upper front teeth that are retroclined (tilted toward the roof of the mouth) and an increased overbite (vertical overlap of the front teeth), which can cause oral problems and may affect appearance. This problem can be corrected by the use of special dental braces (functional appliances) that move the upper front teeth forward and change the growth of the upper or lower jaws, or both. These braces can be removed from the mouth and this approach does not usually require removal of any permanent teeth. Additional treatment with fixed braces may be necessary to ensure the best result.

An alternative approach is to provide space for the correction of the front teeth by moving the molar teeth backwards. This is done by applying a force to the teeth from the back of the head using a head brace (headgear) and transmitting this force to part of a fixed or removable dental brace that is attached to the back teeth. The treatment may be carried out with or without extraction of permanent teeth. If headgear use is not feasible, the back teeth may be held in place by bands connected to a fixed arch placed across the roof of the mouth or in contact with the front of the roof of the mouth. This treatment usually requires two permanent teeth to be taken out from the middle of the upper arch (one on each side).

No RCT evidence to determine best technique for exposing displaced eye teeth

Permanent canine teeth in the upper jaw usually erupt into the mouth between the ages of 11 to 12 years. In 2% to 3% of young people, the canine teeth fail to erupt (grow down) and become displaced in the roof of the mouth (palate).This can leave unsightly gaps, cause damage to the surrounding roots (which can be so severe that neighbouring teeth are lost or have to be removed) and, occasionally, result in the development of cysts.

Management of this problem is both time consuming and expensive. It usually involves surgical exposure (uncovering), followed by fixed orthodontic braces for two to three years, to move the canine into the correct position. Two surgical techniques are routinely used in the UK: the closed technique involves uncovering the buried tooth, gluing an attachment onto the exposed tooth and repositioning the palatal flap. Shortly after surgery, an orthodontic brace is used to apply gentle forces to bring the canine into its correct position within the dental arch. The canine moves into position beneath the gum. An alternative method is the open technique, which involves surgically uncovering the canine tooth as before, but instead of placing an attachment onto the exposed tooth, a window of gum from around the tooth is removed and a dressing (pack) placed to cover the exposed area. Approximately 10 days later, this pack is removed and the canine is allowed to erupt naturally. Once the tooth has erupted sufficiently for an orthodontic attachment to be glued onto its surface, orthodontic braces are used to bring the tooth in line with the other teeth.

Lasers may help to reduce pain in orthodontic treatment: but more high quality research is needed

Pain is usual during orthodontic treatment, especially when a brace is placed on the teeth. Later adjustments of the brace can also result in pain, sometimes lasting up to a week or more. This can make people stop their orthodontic treatment, meaning that the benefits are lost. Painkillers have been recommended to reduce pain, but an effective non-drug solution would lower the risk of side effects and help people follow the full course of treatment.

Retaining tooth position after orthodontic treatment

Once people finish having their teeth straightened with orthodontic braces, the teeth will tend to get crooked again. Orthodontists try to prevent this by using different retention procedures. Retention procedures can include either wearing retainers, which fit over or around teeth, or stick onto the back of teeth, or by using something called ‘adjunctive procedures’. Adjunctive procedures either change the shape of the contacts between teeth, or involve a very small procedure to cut the connection between the gum and the neck of the tooth. This is an update of a Cochrane review published previously in 2006.