Classification of teeth and Face

Classification of Teeth

The classification of bites are broken up into three main categories: Class I, II, and III.

Classification of Teeth Overview

For a brief overview of the classification of teeth, please click on the image below. It will launch our educational module in a separate window that may answer some of your questions about the classifications of teeth.

Classification of Teeth Overview
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Class I:
Class I is a normal relationship between the upper and lower teeth and a balanced bite.

Class I Normal
Normal

Class I Crowding
Crowding

Class I Spacing
Spacing

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 retrusive chin and lower lip. Class II problems can be due to insufficient growth of the lower jaw, an overgrowth 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 teeth, lower teeth and jaws into harmony.

Class II Division I
Division 1

Class II Division II
Division 2

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 mandible project further forward than the upper teeth and maxilla. The facial profile could have a concave appearance with a prominent chin. Class III problems are usually due to an overgrowth in the lower jaw, undergrowth of the upper jaw or a combination of the two. Like Class II problems, they can be genetically inherited.

Class III Skeleton
Skeleton

Class III Dental
Dental

Classification of Face

It is not sufficient to categorize orthodontic malocclusions on the basis of a classification of the teeth alone. The relationship with other craniofacial structures must also be taken into consideration.

Class 1:

Maxillary-Mandibular Dental Protrusion — teeth
Maxillary-Mandibular Dental Protrusion:
This is an example of a dental malocclusion that may require the removal of teeth for correction.

Maxillary-Mandibular Dental Retrusion — teeth
Maxillary-Mandibular Dental Retrusion:
This is an example of a dental malocclusion that may be treated with expansion rather than removing teeth.

Class 2:

Maxillary Dental Protrusion — teeth
Maxillary Dental Protrusion:
This malocclusion may require the removal of few teeth.

Mandibular Retrognathism — jaws
Retrognathism of the Mandible:

The lower jawbone has not grown as much as the upper jaw. This example of a Class II malocclusion demonstrates the need for early growth guidance.

Maxillary Dental Protrusion — teeth & Mandibular Retrognathism — jaws
Maxillary Dental Protrusion & Retrognathism of the Mandible:
These malocclusions are more difficult to treat due to the skeletal disharmony and may require orthognathic surgery in conjunction with orthodontic treatment.

Class 3:

Mandibular Dental Protrusion — teeth
Mandibular Dental Protrusion:
The lower teeth are too far in front of the upper teeth. This malocclusion is treated with orthodontic procedures which may require the extraction of few teeth due to the dental protrusion.


Prognathism of the Mandible:
The lower jaw bone has outgrown the upper jaw. This malocclusion is more difficult to treat due to the skeletal disharmony and may require orthognathic surgery in conjunction with orthodontic treatment.