In the normal human mouth, when the upper and lower teeth occlude, i.e., they come in contact, this happens in such a way that the upper teeth are always on the outer side (buccal) when compared to lower teeth. This is the normal position of occlusion of the jaw. However, when teeth are misaligned in a jaw, then there could be a condition where one tooth or a group of teeth of the lower jaw are more buccally (outwardly) placed compared to the teeth of the upper jaw. This condition is known as a crossbite. Crossbite in children and adults is not unheard of, as this is a common type of malocclusion seen.
There can be many different causes that can lead to a crossbite. First, what one needs to identify is whether the condition is skeletal or dental in nature. If the condition is skeletal in nature, then this crossbite could occur due to a small upper jaw (maxilla), a large lower jaw (mandible) or both. In such cases, there may be congenital micrognathia of the upper jaw, that is, the presence of an abnormally small upper jaw and a normal lower jaw. This will mostly lead to both anterior and posterior crossbite in children, that is, a complete crossbite.
When the problem is purely dental, i.e., only due to misaligned teeth, then this is mostly caused because of a habit or due to lesser space in the jaws and crowding teeth. When a child has a habit of mouth breathing, then in an attempt to breathe in more air through his mouth, his jaw opening increases. This leads to an increase in the length of the face, which also causes the occlusion to shift distally, that is, move backwards. The other cause of crossbite, especially anterior crossbite in kids, is dental crowding. This is a condition where the teeth erupt in positions that are slightly anterior or posterior to their actual positions in the jaw due to insufficient space. This may also occur in cases where the normal eruption timing of teeth has been changed. This occurs when a person gets his milk teeth extracted and his permanent teeth erupt before time due to the empty space. This could eventually lead to crowding and a disruption in the normal eruption sequence and alignment of teeth.
The treatment for crossbite in children will depend on the underlying cause. If the cause is skeletal in nature, then a crossbite surgery might be needed. This will include correction of the skeletal deformity, by bringing forward the retruded maxilla, or pushing the protruded mandible backward, or both. If the problem is purely dental in origin, then orthodontic treatment will help in correcting this condition. This consists of placing orthodontic braces in the mouth and using force generated by tightening wires to bring teeth into their desired position. Sometimes, there may be need for both, surgical correction and eventual orthodontic treatment to deal with this problem.
If there is a slight crossbite that is only present in the milk teeth, then this can be left untreated for a while. However, if it develops in case of permanent teeth, then it is best to correct it at the earliest. This is because a crossbite leads to a lot of problems, like difficulty in maintaining dental care, which eventually affects the oral health of the individual. Hence, it is best to get a crossbite treated before it leads to any more complications.
Disclaimer: This article is for informative purposes only, and should not be used as a replacement for expert medical advice.