The teeth on the left side of my jaw are "longer" then the teeth on the right, how does this happen?

Completely random question I know, but I've always wondered about this. The teeth on my right side of my mouth are shorter then the teeth on the left side. If I take my index finger and slide it under my teeth on the right side then about 3/4 of my finger can still be felt (seen), if I do this on the left side only about 1/3 of my finger can be felt (seen). I've never hit my jaw on anything, never broke my jaw, etc. I do however chew only on the left side... could that "sharpen" my teeth more or something? I'm just curious why one side would be a bit longer then the other.