The body is an amazingly clever and well-designed system. For most lucky people our adult teeth come down in the right place and things look and feel pretty good. However there can be various issues that cause teeth not to be straight.
For example, you could have any combination of the following:
The immediate effect of having crooked teeth can be on how you breathe, eat, speak, kiss and smile. In particular; musicians, singers, actors and broadcasters can be very sensitive to any changes in the mouth. Athletes need a great airway to facilitate their sport.
There can be knock on effects in terms of your dental health, particularly if your bite is thrown out. This can impact how stable your teeth and jaw joints are over your lifetime.