Why should you wear one?
As its name suggests, for protection. A mouthguard cushions your mouth against impacts if you take a hit.
It of course protects your teeth; from breaking, moving, or being knocked out, whether caused by the strike itself or from teeth jarring together. But it also does more than that. A mouthguard can also protect the gums if it covers them. Covering the gums significantly reduces the risk of teeth being knocked out.
What is known as the soft tissues are also protected, this includes the lips, tongue, and inside of the cheeks, as the mouthguard forms a barrier between the teeth and tissue. If you bite down after taking a hit or if the hit is too hard, because an uncontrolled hit is always possible, the mouthguard will greatly reduce the impact.
Very good reasons to make sure you wear one!