Malocclusions
The following malocclusions (Dysgnathia) may occur alone or in combination with each other.
Dysgnathia are malformations of the teeth and jaw.
The following malocclusions (Dysgnathia) may occur alone or in combination with each other.
In neutral occlusion (Angle Class I) the teeth are well aligned, with the lower teeth only 1-2mm behind the upper teeth in the closed position. All teeth have have contact with each other. Neutral occlusion can occur in combination with crowding, with gaps* or a protrusion* of the teeth.
The overbite (distal occlusion, retrusive occlusion – Angle Class II) is the most common form of malocclusion. In retrusive occlusion the lower jaw is too far back, leaving a large gap between the incisors.
The closed bite (Angle Class II, Div. 2) is a special form of retrusive occlusion. In a closed bite some of the front upper teeth are typically tilted backward and the rest tilted forward. Possible consequences:
The underbite is a somewhat rarer form of malocclusion. Here the lower jaw protrudes in front of the upper jaw. Sometimes the edges of the incisors meet; or the lower incisors are even in front of the upper ones, which is called a “crossbite”.
In a lateral crossbite the lower molars protrude over the upper molars. The crossbite can occur on one side, on both sides, or even in the front teeth (see underbite).
An open bite means that the upper and lower incisors do not come into contact with each other even when the jaw is closed. In extreme forms only the back molars touch when the jaw is closed.
Bialveolar protrusion designates the “tilting out” of the front teeth. In this case either the molars must be moved back so that the front teeth can be returned to the jaw bone, or healthy teeth must be extracted. In adults this dental movement often begins suddenly when periodontis occurs (inflammation of the gums with bone loss).
When the teeth are crowded, the front teeth are displaced and or crossed, sometimes so severely that some teeth are located behind the others in the same row.
Rows of teeth with gaps are detrimental to facial appearance. Gaps due to tooth loss should be promptly remedied with a bridge or an implant, since otherwise the adjacent teeth may tilt into the gap, making further dental treatment difficult without first opening the gaps through orthodontics.