Malocclusion - The Essentials
Occlusion is a term that refers to the proper biting alignment of upper teeth with the lower teeth. Proper alignment entails that the upper teeth project slightly outward over the lower teeth during biting. This helps in two ways. The above alignment helps prevent upper teeth from biting the cheeks or lips and the lower teeth from biting the tongue.
Besides this, another feature of the above proper alignment is that the sharp points of the molars in one jaw fit seamlessly into the grooves of the corresponding molars in the other jaw and all teeth project straight, are aligned, and are proportionally spaced.
Malocclusion is a condition in which the above proper alignment is disturbed significantly. It is observed in practice that very few people have perfect alignment of their upper teeth with their lower teeth. However, in most such cases the deviation is so slight and minor that treatment is not necessary.
However in some individuals, the deviation from the proper alignment is either severe or moderate. In these cases, treatment for malocclusion will be necessary.
Reasons for severe or moderate malocclusion include disproportionate sizes of the two jaws on the one hand and that between tooth size on the other or that between the respective sizes of the upper and lower jaw.
Overcrowding and abnormal bite are consequences of such disproportion. The loss of a tooth or more than one tooth can be another reason for such malocclusion. This is because the empty space that results through the loss of a tooth is immediately attempted to be covered by adjacent teeth. This disturbs their alignment.
Some other uncommon reasons for significant malocclusion is that caused due to fracture of a jaw, thumb sucking after age 4 years, jaw tumors or those of the mouth, improper fillings, crowns, and incorrect fitment of braces and retainers. Hereditary factors are thought to play a role in significant malocclusion. Birth defects such as cleft palate and lip may also be responsible for such malocclusion.
Malocclusion can occur due to impacted teeth or due to teeth eruption in significantly skewed directions.
Malocclusions are of three types.
Type 1 is the most common. It results due to overcrowding of teeth or their malpositioning. However, in such a case, the bite is still observed as normal.
Type 2 is known as retrognathism. This occurs due to the overbite caused due the teeth in the upper jaw overlapping the teeth in the lower jaw.
Type 3 is known as prognathism. In this condition, the lower jaw protrudes more than the upper jaw does so that the lower teeth extend over the upper teeth. This results in an underbite.
Braces are used to treat malocclusion or even to prevent malocclusion due to other teeth from shifting into the space vacated by loss of teeth. Jaw fractures are corrected through surgery. Binding of teeth together using crowns and selective teeth grinding are some other solutions for minor malocclusion.