The classification of bites are broken up into three main categories: Class I, II,
and III. This classification refers to the position of the first molars, and how
they bite together.
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Class 1
Class I is a normal relationship between the upper and lower teeth and jaws, or
balanced bite.
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A normal bite (stripe indicates alignment of molars)
Class 1 - Normal
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Class 1 - Crowding
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Class 1 - Spacing
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Class II
Class II is where the lower first molar is posterior (or more towards the back of
the mouth) than the upper first molar. In this abnormal relationship, the upper
front teeth and jaw project further forward than the lower teeth and jaw. There
is a convex appearance in profile with a receding chin and lower lip. Class II problems
can be due to insufficient growth of the lower jaw, an over growth of the upper
jaw, or a combination of the two. In many cases, Class II problems are genetically
inherited, and can be aggravated by environmental factors such as finger sucking.
Class II problems are treated via growth redirection to bring the upper and lower
teeth and jaws into harmony. In severe cases, jaw surgery may be required.
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Class 2 - Division 1
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Class 2 - Division 2
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Class III
Class III is where the lower first molar is anterior (or more towards the front
of the mouth) than the upper first molar. In this abnormal relationship, the lower
teeth and jaw project further forward than the upper teeth and jaws. There is a
concave appearance in profile with a prominent chin. Class III problems are usually
due to an overgrowth in the lower jaw, an undergrowth of the upper jaw, or a combination
of the two. Like Class II problems, they can be genetically inherited.
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Class 3 - Functional or Dental
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Class 3 - Skeletal
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