Common Orthodontics Problems

A posterior cross bite is a poor bite where the upper back teeth sit inside the lower teeth. In a healthy bite it should be the opposite. Posterior cross bites can occur on one side (unilateral) or both sides (bilateral). Usually they occur as a result of a narrow upper jaw. This can be accompanied by a restricted nasal airway. Unilateral cross bites are particularly worrisome as they can create lower jaw asymmetries.