What is an overjet and overbite?
Horizontal overlap of the upper teeth to the lower teeth is called an overjet and vertical overlap is called an overbite. Normal overjet and overbite are 2 mm.
What causes an increased overjet and overbite ?
An increased overjet could be caused by the upper jaw being placed forward to the lower jaw or the lower jaw being placed backward or being a smaller size to the upper jaw. Apart from this the upper teeth could be more proclined and the lower more retroclined which could be increase the overjet further.
An increased overbite in many cases could be the result of an increased overjet where the lower front teeth has the freedom to continue to erupt until it contacts the palate or the back off the upper teeth.
Hereditary /Genes plays an important role in development of such malocclusions but certain other factors such as bad habits like thumb sucking, tongue thrusting can also be involved.
Treatment
Usually involves functional appliances that could decrease the overjet by bringing the teeth closer and in many cases extractions of 2 teeth in the upper arch or 2 in the upper and 2 in the lower may also be required to achieve an ideal result. Treatment would take approximately 24 to 36 months depending on the severity of the problem.
Below is a case treated in a patient having a large overjet and 100% deep bite with extraction of 2 teeth in the upper. Before and after photos of teeth are attached
Before braces: Deep overjet and 100% overbite (lower teeth not visible)
After Braces: Ideal overjet and overbite, lower front teeth are visible, treatment time 18 months treated at Align Dentistry & Medical Centre and Orthodontics