Many people have to have a tooth removed at some time in their lives. This can be for a number of reasons.
Some people have overcrowded mouths, and have some teeth removed as part of their orthodontic (teeth straightening) treatment.
Sometimes teeth become too badly decayed or damaged to be repaired, and need to be extracted. Gum disease can, in its later stages, cause teeth to become so loose that they have to be taken out. And some people have to have their wisdom teeth removed, usually because they are growing in the wrong direction and are causing problems.