Why cross bite occur in upper lateral incisors?

Answer 1

There are many reasons why crossbites occur. One is jaw size and heredity. Another is delayed loss of baby teeth. Some people keep their baby teeth so long that their permanent teeth come in behind their baby teeth, like a second row of teeth. If this happens in your upper jaw, the permanent top front teeth may wind up sitting behind the lower front teeth when you bite down. This can happen on one side (unilaterally) or on both sides (bilaterally).

Mouth breathing by children can also spur the development of a cross bite. Normally, children breathe through their nose; the mouth is closed, and the tongue sits on the roof of the mouth. This tongue position is very important because it causes the upper jaw to grow out laterally, or sideways, as it should. Children who have big adenoids and tonsils tend to breathe almost exclusively through their mouth, especially while asleep. Snoring is another symptom.

When children are forced to breathe through their mouth all the time, their tongue drops from the roof of the mouth, and lateral growth of the upper jaw becomes inadequate. Adult teeth growing in a narrow upper jaw can become squeezed inward and land behind the bottom front teeth whenever the child bites down.

Tipped off by this telltale pattern of malocclusion, an orthodontist often is the first health-care professional to notice that a child's adenoids and tonsils are too large. The orthodontist generally refers the patient to an ear, nose and throat specialist.

Aside from mouth breathing and snoring, parents should suspect a crossbite if their child slides his/her lower jaw to the left or right in order to chew comfortably, or if their child's chin appears off-center.