There are two primary uses for mouthguards. The first is for active kids and adults who participate in team sports or other activities that may cause injury about the face and head. Mouthguards have been shown to protect teeth and gums and decreases the potential of concussions for all athletes.
The second use is to prevent nighttime grinding and clenching, or bruxism, which can exacerbate TMJ/TMD symptoms (a disorder of the jaw that causes pain in the sinuses, neck, and face), and can cause teeth to wear or crack prematurely. They are a great way to protect your dental investment!