Yes, it is possible to do only upper teeth, but most people need to get both aligners. This is because a shift in the upper teeth can cause changes in the bite, which will affect the lower teeth. So to get a perfect bite and straight, healthy teeth, the whole mouth usually needs to be treated. Even if you think you need the upper or lower aligners only, our dental team still needs both sets of impressions from you in order to make your treatment plan.