Class II problems represent an abnormal bite relationship in which the upper jaw and teeth are located in front of the lower jaw and teeth. Class II patients usually exhibit a convex facial profile with a recessed chin. In most cases, this relationship is due to inherited characteristics.
A skeletal Class II problem occurs when the upper back molars are forward of the lower back molars. This gives the patient the appearance of having a recessed lower jaw, a protruding upper jaw, or both.
Class III problems are also primarily genetic in origin. In this instance, the lower jaw and teeth are positioned in front of the upper jaw and teeth. The lower jaw may appear to be excessively large, but in many cases the lack of upper jaw development is at fault. Several treatment options are available to correct a Class III problem.
A posterior crossbite (of the back teeth) will usually result from a narrow upper jaw or abnormally wide lower jaw. A narrow upper jaw will often force a patient to move the lower jaw forward or to the side in order to close into a stable bite. When closed into this position, the lower teeth are located outside the upper teeth.
A posterior crossbite can involve one side of the jaw, known as a unilateral crossbite, or both sides of the jaw, known as a bilateral crossbite.
An anterior crossbite (of the front teeth) can cause the lower jaw to come forward in an unhealthy way, and cause wearing or chipping of the front teeth.
It is critical to correct crossbites as soon as possible, in order to avoid worn or chipped teeth, or irreversible unhealthy facial growth that may require jaw surgery to correct. Two-phase treatment is ideal to address crossbites early, and avoid major issues later.
Crowding of the teeth is probably the most common orthodontic problem. Although many factors contribute to dental crowding, this problem typically stems from a discrepancy between the space in each jaw and the size of the teeth.
Crowding is often one of several orthodontic problems. Crowding can be the cause or result of other problems, such as impacted teeth, retained teeth, or teeth that do not fall out naturally. Crossbite of the front or rear teeth can also cause teeth to become crowded.
Two-phase treatment can help to lessen crowding or eliminate it altogether, before the crowding leads to other issues, such as gingival/gum defects, which may require surgery.
A deep bite is excessive vertical overlapping of the front teeth and is generally found in association with a discrepancy between the length of the upper and lower jaws. It usually results in excessive eruption of the upper or lower incisors, or both. The lower front teeth often bite into the roof of the mouth.
Excessive Gingival Display
Also known as a gummy smile, this orthodontic problem gives the appearance of excessive exposed gums on the upper arch. There are several treatment options. It may simply require lifting the upper front teeth using braces to help reduce the excessive gum display.
In more severe cases of jaw discrepancy, surgery may be necessary to lift the upper jaw and help reduce the excessive exposure of the upper gum tissue.
An open bite can occur with the front teeth, known as an anterior open bite, or with the back teeth, a posterior open bite.
An anterior open bite involves a lack of vertical overlap of the front teeth and can usually be traced to jaw disharmony or habits such as thumb-sucking or the thrusting of the tongue against the front teeth.
A posterior open bite is a problem in which the back teeth do not meet vertically, which keeps the jaw from functioning properly.
Overjet is the horizontal distance between the back surfaces of the upper front teeth and the front surfaces of the lower front teeth. If the overjet is excessive, the upper front teeth appear to protrude ahead of the lower lip.
Pseudo Class III
Pseudo Class III, particularly in younger patients, is a function of habit rather than hereditary factors. A misaligned bite may cause the lower teeth to bite forward of the upper teeth, giving the appearance of a Class III. Two-phase treatment is imperative to prevent abnormal growth of both the upper and lower jaws.
Spaces between teeth are another common problem that call for orthodontic care. Like crowding, spacing may be related to a tooth-to-jaw size disharmony.
Spacing may occur between the front and the back teeth. Tooth size discrepancies, such as smaller teeth or abnormally shaped teeth, or tongue thrust habits, can also create abnormal spacing.