When you are missing one or more teeth, it's important to replace them. There are several reasons why it's important. A replacement tooth prevents other teeth from shifting and tilting, which is bad for your bite and for the appearance of your smile. The gap left by the missing tooth can lead to a misaligned bite, which can be uncomfortable and can create problems when you chew and speak. A missing tooth can cause the bone beneath your gums to shrink, and gaps in your smile may make you feel unhappy with the appearance of your smile.