Orthodontics is that branch of dentistry which specialises in the diagnosis, prevention and treatment of problems in the alignment of teeth and jaws. The technical term for these problems is malocclusion, which literally means bad bite. Orthodontic treatment involves the design and use of corrective appliances (such as braces, plates, headgears and functional appliances) to bring the teeth and jaws into proper alignment.


Crowded teeth

A disharmony between tooth-size and jaw- size can result in crowded, irregular teeth.Crowded teeth can be unattractive and more difficult to clean. They are prone to uneven wear. Orthodontic treatment usually involves the use of braces which are the most efficient and accurate way of aligning teeth. Sometimes it is necessary to extract teeth to provide sufficient space to allow the teeth to be aligned in a stable and harmonious position within the jaws and face.

Spaced teeth

Spaces can result from a disharmony between tooth-size and jaw-size or by abnormal tongue thrusting activity. Spaces between the teeth can look unattractive and can interfere with speech. Orthodontic treatment usually involves the use of braces to align the teeth and to close the spaces. Abnormal tongue activity must be eliminated or the spacing is likely to recur.

Protruded teeth

Protruded teeth result when the position of the upper jaw is forward of the lower jaw. In severe cases, the lower lip may sit behind the upper front teeth and push them further forward to accentuate the disharmony. Protruded teeth can be unattractive and prone to accidental damage. Often teeth become worn unevenly. Sometimes, the lower front teeth can over-erupt and damage the gum behind the top front teeth. Orthodontic treatment involves the aligning, levelling, and coordination of both arches with braces. In growing patients, the bite is corrected with headgear, elastics or functional appliances. In severe cases, especially if growth is complete, jaw surgery might be required to correct the jaw disharmony.


When the lower jaw is forward in relation to the upper jaw, the lower front teeth protrude beyond the upper teeth and an "under-bite" results. An under bite can be unattractive and can cause uneven wear of the front teeth and jaw joint problems.

Deep bite

The upper and/or lower front teeth can overupt to produce a deep bite. In severe cases, the upper teeth can cover the lower teeth completely. A deep bite can cause excessive wear of the front teeth and can damage the gum behind the upper front teeth. Deep bites can exert excessive strain on the jaw joint resulting in tempero-mandibular joint problems.


An open-bite exists when opposing teeth don't meet. An open-bite can cause eating problems and excessive wear of those teeth which do make contact. An open-bite can be unattractive and can be associated with speech problems. Open-bites are often caused by abnormal tongue habits and, although the open-bite can be closed with braces, unless the abnormal tongue habits are corrected, the open bite is likely to recur.

Posterior Cross-bite

The upper teeth should fit outside the lower teeth like a lid on a box. If the upper jaw is too narrow, the lower jaw usually swings to one side to allow the back teeth to mesh.A posterior cross-bite results. Posterior cross-bites can result in uneven wear of the teeth and can place extra strain on the jaw joint resulting in tempero-mandibular joint problems.

Missing teeth

Missing teeth usually result in unattractive spaces. Opposing and adjacent teeth can drift into the space to create further problems. Orthodontic treatment involves moving all teeth into correct position, and creating proper space to facilitate replacement of the missing teeth with prostheses. In certain situations, it is possible to close the spaces and avoid having to replace teeth with prostheses.

Impacted teeth

Impacted teeth don't have sufficient space to erupt. Orthodontic treatment involves creating space to allow the impacted tooth to erupt.

Ectopic teeth

Ectopic teeth are teeth which develop in the wrong position. In most cases, ectopic tooth can be moved into the correct position with braces. In this case, an ectopic canine (eye tooth) was surgically exposed and braces were used to move it into its correct position.

Thumb sucking

Sucking the thumb (or fingers) can produce a localised deformation of the teeth and supporting bone. Once the sucking habit has been stopped, as illustrated on the right, natural improvement can occur.

Other problems

An orthodontic opinion might also be sought when there is:

Difficulty in chewing or biting 
Speech difficulty 
Grinding or clenching of teeth 
Jaws that shift or make sounds