We don't really know although there are plenty of theories.

• Our modern diet is less abrasive than in the past and this means we don't wear the enamel down as much as we used to in between the teeth, which made the teeth significantly less wide and therefore less crowded.
• The softness of our modern diet causes the jaw muscles to be lacking in sufficient exercise for the jaws to develop properly.
• Air pollution is said to cause inflammation of the lining of the nasal cavity leading to mouth breathing. This requires the jaw and tongue to drop a little to allow air to pass which, in time, leads the upper jaw to become narrow and crowded.
• The combination of big teeth and small jaws. It is a fact that people with small teeth are less likely to have crowding.

Take your pick! The first three theories are environmental or blame modern man's life style. Only the last theory has a genetic component. There are good arguments against all these theories, indicating that crowding is likely to have more than one cause and be based on various combinations of genetic and environmental influences.

Clearly, each patient needs to be assessed individually. This is why we apply a process known as space planning which identifies all aspects of the dentition before treatment begins and the effects that corrective measures will have. This process determines which cases need extractions and which don't, and when various options are possible.

We are aware that the extraction of teeth is an issue that can arouse strong emotional feelings. However, we pursue evidence-based clinical practice and recommend the extraction of teeth only when absolutely necessary. The large majority of patients are treated without extractions. These are undertaken only when failure to extract would result in a poor appearance due to the teeth being too far forward or in the teeth being in unstable positions.

For information on the effect of extractions on facial profiles, click here.