Malocclusions (bad bites) are described under standardised groupings which have become accepted world-wide. These groupings allow universal classification of problems and enable dental professionals to communicate using the same terms.

Class I malocclusion
Class-I-malocclusion

Here the teeth meet in good positions and the overbite and overjet are correct, but the teeth are crowded. Depending on the degree of crowding, space may need to be made by removing some teeth before braces can be put on. In Britain about 45% of the population have malocclusions of this type.

Class II division 1 malocclusion
Class-II-division-1-malocclusion

The upper teeth are projecting forwards of the lowers (the overjet is increased) and the upper incisors are proclined. Crowding may also be present. This arrangement is seen in about 34% of the population. Depending on the degree of discrepancy, headgear, extractions or surgery may be needed to create a good correction.

Class II division 2 malocclusion
Class-II-division-2-malocclusion

The upper teeth are again protrusive, but the upper incisors are retroclined (tipped backwards). The overjet may not be greatly changed but the overbite is often greatly increased giving a “deep bite”. Treatment is similar. About 18% of malocclusions are like this.

Class III malocclusion
Class-III-malocclusion

Here the lower teeth are positioned ahead of the uppers (a reverse overjet). About 2% of malocclusions belong to this class. There is often an associated jaw misalignment, either upper or lower. These patients often need a combination of braces and a jaw operation to treat well. Because the lower jaw is one of the last bones to stop growing, treatment is often delayed until the patients are adults, so that a correct treatment plan is made.

Problems to watch for in children

Anterior Crossbite

Anterior Crossbite
(Scissor bite arrangement)

Posterior Crossbite

Posterior Crossbite
(Upper arch too narrow)

Crowding

Crowding
(Overlapping teeth)

Open Bite

Open Bite
(Teeth don’t meet at the front – can be caused by thumb sucking)

Protrusion

Protrusion
(Goofy – upper jaw too far forward)

Complete Class III

Complete Class III
(Lower jaw protrudes forward of upper jaw)

Diastema

Diastema
(Spacing)

XRay

Other problems
Some problems can occur of which can only be seen on x-ray.

Problems to watch for in adults

Crowding

Crowding
(Overlapping teeth)

Diastema

Diastema
(Spacing)

Anterior Crossbite

Anterior Crossbite
(With forward displacement)

Bruxism

Bruxism
(Tooth wear)

Periodontal Problems

Periodontal Problems
(gum disease)

Protrusion

Protrusion
(Goofy – upper jaw too far forward)

Open Bite

Open Bite
(Teeth don’t meet at the front)

Deep Bite

Deep Bite
(Top teeth overlap lower teeth)

Note from the specialist

All malocclusions illustrated above can be improved by orthodontic treatment.