Another way your teeth work together is in even distribution of the pressure from chewing. If you lose a few teeth, the remaining teeth may then be under additional pressure, since that pressure isn’t being evenly distributed anymore. For example, losing a back molar may look fine in terms of smile aesthetics, but those back teeth take on a lot of the heavy duty chewing work. With one gone, the others will have to shoulder more work. This can lead to excessive tooth wear, and can even cause chips or cracks.