The technical term for a “bad bite” is a malocclusion. There are many different types of malocclusions depending on what the exact nature of the problem. Sometimes, a poor bite only develops on one side of the mouth instead of both sides. This situation, which is commonly known as a crossbite, happens because of an asymmetry of the teeth or jaw. This lack of balance can occur when some of the teeth on one side are lost, or if they never come in at all.
In a bi-lateral crossbite, (meaning one side only), the top teeth on one side close either outside or across the bottom teeth. This happens because the lower jaw shifts from side to side when the mouth is closing in an attempt to correct for the mismatch of the upper jaw and the lower jaw. This shift creates a misalignment of the teeth.