An overbite means that there is an extensive vertical overlap of the maxillary central incisors in relationship to the lower (mandibular) central incisors. An overbite does not technically mean the same thing as retrognathia, which is a condition where the lower jaw is smaller than or behind the upper jaw, resulting in abnormal placement of the teeth. It is also sometimes confused with an “overjet” in which there is a horizontal difference between the upper teeth and lower teeth. Basically the top teeth protrude too much in an overjet. You can have both an overbite and an overjet, however. Everyone has an overbite of about 3-5 mm between the upper and lower teeth. Anything greater than this represents an abnormal overbite.
An overbite accounts for 70 percent of malocclusion problems in children, making it the most common tooth relationship abnormality in kids.
Types of overbite:
There are two types of overbite in general. There is the “vertical overbite” in which the maxillary teeth overlap the lower teeth in a vertical direction. There is also the “horizontal overbite” or “overjet” in which the top teeth protrude too much. Some individuals will have both abnormalities at the same time.
What are the causes of an overbite?
Overbites are considered to be mostly related to heredity. You inherit a predisposition to an overbite just like you inherit the color of your eyes and the color of your hair. It may show up when you have your baby teeth or not until your adult teeth come in. It is made worse by things such as thumb sucking behaviors, tongue thrusting and the use of a pacifier or baby bottle beyond the age of two to three years. At this tender age, the jaw can become malformed as a result of the behaviors, leading to malocclusion. Depending on how the behaviors are done and genetics, an underbite or an overbite can occur. Teeth are often crooked, which exacerbates the problems with the occlusion or the bite.
Symptoms of the overbite:
There may be no symptoms of an overbite, with the exception of the appearance, which is usually unacceptable to some. Other symptoms are painful chewing or inadequate ability to chew. Chewy foods are difficult to eat, such as pizza, because of the malocclusion and there can be jaw pain.
You can have headaches and pain in the jaw along with damage to bone along the temporomandibular joint space. The temporomandibular joint or TMJ is the joint that makes the mandible open and close during chewing and just opening your mouth. If there is misalignment of teeth, there is extra pressure on the TMJ and the cartilage and bone can wear away, leading to TMJ arthritis. Not everyone gets clicking of the jaw or TMJ pain but enough do to make it a problem.
What kind of complications overbite may result in?
Some of the complications of an overbite are simply aesthetic. Having what some kids call “buck teeth” is hazardous to a child’s self esteem. In addition, having buck teeth means that the teeth are more prone to trauma and breakage. These teeth are more prominent and are just more obviously placed to be traumatized. Physically, the major complication includes having temporomandibular joint disease, in which the cartilage and bone wear away, leading to headaches and grinding of the joints. Some people need surgery of the temporomandibular joints so that the joint is restored, albeit an artificial joint.
Overbite Prevention:
Some aspects of an overbite cannot be avoided because they are hereditary and can’t be changed. They can be treated but not prevented. Ways to prevent an overbite are to avoid thumb and finger sucking, sucking on a pacifier or using a bottle past the age of three. Avoiding tongue thrusting at a young age will make a difference in getting or not getting an overbite.
Treatment options:
You can treat a young child with an overbite using a functional appliance similar to a retainer. It is a system of wires and plastic that is worn in the mouth to prevent a worsened overbite or to treat one that is already there. You can wear a lower appliance in order to force the growth of the mandible so it fits with the maxilla and the maxillary teeth. You can use functional appliances in kids that are around seven to nine years of age. The child wears the retainer for several years and then gets braces after that.
Functional appliances are often worn around the clock and shorten the length of time the child needs braces or perhaps can avoid braces completely. You can avoid extracting certain teeth because the whole mouth fits better together. The aesthetics of functional appliances is better because the overall jaw positions are more balanced.
Adults can have their overbite fixed and can begin to chew better by wearing an adult sized functional appliance.
The classical treatment for an overbite is to use braces. It takes about two years and takes about two stages. In stage I of treatment, braces are used to level the teeth and align them so that there are no crooked or twisted teeth. In stage II, the overbite is tackled by pushing back the molars and the incisors together so that the teeth are in the proper position. The bottom teeth are pushed forward at the same time so that the bite is better.