I often have been asked as many people say

well here are a few

1, trauma if you broke the teeth or they were chipped then this can cause a

2, the lips and tongue can exert pressures on the teeth causing them to develop in unusal places

3, ealry loss of the baby teeth this can cause the space to close too soon for the adult tooth

4, missing adult teeth

5, mesial drift- whereby the back teeth move gradully move forwards causing some crowding in the front teeth

6, extra teeth

7, big teeth and small mouth can cause crowding

these are the main reasons there may be more if i think of more will post agian on this subject most of these can be corrected using some kind of brace or orthodontic treatment