Braces are used to move teeth into the ideal position and align how they bite together, known as
occlusion.
Malocclusion is used to describe the misalignment of teeth between the upper and lower dental arches, using the first molars as a reference point. There are three different types of misalignment, defined by the Angle's Classification Method. Developed by Dr. Edward Angle, considered by many the founding father of orthodontics, this method of classification is widely used by dentists around the world:
Class I - Considered the ideal relationship between the upper and lower teeth. Crowding or spacing may be present with Class I bite.
Class II – Commonly known as “over bite.” The patient’s lower first molar is positioned posterior, or more towards the back of the mouth. The upper jaw, or maxilla, appears to protrude forward. Class II bite has two sub classes that also describe the position of the upper front teeth, but in both cases, the molar relationship is the same.
Class III - The patient’s lower first molar is positioned anterior, or closer to the front of the mouth. The lower jaw, or mandible, protrudes forward, and is best described as an “under bite.”
Causes of malocclusion
Most malocclusions are caused by hereditary factors that affect the contours of the face and the size of the teeth and jaw. The most common cause of
malocclusion is a disproportion in size between the jaw and teeth or between the upper and lower jaws. A child who inherits a mother's small jaw and a father's large teeth may have teeth that are too big for the jaw, causing crowding.
While some patients may have the ideal bite, they may suffer from varying degrees of crowding or spacing, another factor associated with a misaligned bite.
Crowding is a condition that causes the teeth to overlap, rotate, and in some cases, grow into the incorrect position in the mouth, or in more extreme cases, cause the tooth to become trapped in the bone. Crowding may be caused because the dental arch is too small for the adult teeth, or the adult teeth are larger than normal. Crowding may also be caused by losing the primary or baby teeth early, or retaining them in the mouth longer than normal. These factors may inhibit the adult tooth, forcing it to erupt or grow into an incorrect position. Crowding makes it difficult to brush and floss the teeth correctly, possibly resulting in tooth decay or gingivitis.
Alternatively, varying degrees of
spacing may be present, due to smaller teeth or jaw size. The most obvious example of spacing is the diastema, a space between the upper two front teeth, known as the centrals, made famous by Madonna!
Untreated malocclusions
Minor misalignment or crowding may not require treatment. However untreated malocclusions can cause the following:
- inefficient or uncomfortable biting, chewing, and digestion
- speech impairments
- teeth that are hard to clean, leading to cavities and gum disease
- abnormal wear of tooth surfaces
- thinning and receding of bone and gums covering the roots of very crowded teeth
- premature loss of teeth
- adverse effects on facial development and appearance
Untreated malocclusions often worsen with time. TMJ problems can cause chronic headaches or pain in the face and neck. A deep overbite can cause significant pain and bone damage and may contribute to excessive wear on the incisors.