Crowding occurs when the teeth do not have enough space next to each other in an arch. In addition to aesthetic problems, this discrepancy makes it more difficult to clean the teeth and can lead to gum inflammation, tartar and tooth decay more easily than with a normal set of teeth.

In contrast to crowded teeth, a gap dentition is when the available space is larger than the teeth need. Most often a gap is formed between the two upper incisors, called diastema, but it can also occur in posterior regions.

The plaque that easily sticks in the gaps can lead to gingivitis and tooth decay.

An open bite is when the upper and lower incisors do not come into contact in a closed position. It can be hereditary or acquired. In childhood, prolonged pacifier sucking, finger sucking, tongue thrust swallowing and mouth breathing can all be predisposing factors.

Open bites can cause not only aesthetic problems but also chewing and speech difficulties.

Crossbite can affect a single tooth or even whole groups of teeth.

• Anterior crossbite is when the lower teeth bite in front of the upper teeth.
• Lateral crossbite is when the upper teeth bite inwards more than ideal because of a narrower upper jaw or wider lower jaw.

This can result in asymmetry, speech and joint problems and abnormal tooth wear.