When a dentist opens your bite, they are increasing the vertical space between your upper and lower teeth. This can be done for a variety of reasons, such as to correct an overbite, underbite, or crossbite. It can also be done to make room for orthodontic treatment, such as braces or Invisalign.
There are a few different ways that a dentist can open your bite. One common method is to use an expander. An expander is a device that is placed in the roof of the mouth and gradually widens it over time. This creates more space between the upper and lower teeth.