Your tongue is attached to your lower jaw. Wherever your lower jaw goes, your tongue goes with it.
If, when you bite your teeth together, your lower jaw is forced backwards (in order to get your teeth to fit together), then your tongue is forced to the back of your throat every time your upper and lower teeth come together. When your tongue is forced to the back of your throat, it can block off your airway and affect your ability to breathe……especially when you are sleeping. Not only does your tongue blocking your airway at night when you sleep cause snoring, but it can also cause daytime sleepiness and fatigue.