Classification of Face and Teeth

Classification of Teeth

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

Class I:
Class I is a normal relationship between the upper teeth, lower teeth and jaws or 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) to 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 issues can be caused by insufficient growth of the lower jaw, an over growth of the upper jaw, or a combination of the two. In many cases, Class II issues are genetically inherited and can be aggravated by environmental factors such as finger sucking. They are usually treated via growth redirection, bringing 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) to the upper first molar. In this abnormal relationship, the lower teeth and jaw project further forward than the upper teeth and jaw. There is a concave appearance in profile with a prominent chin. Class III issues are usually caused by an overgrowth of the lower jaw, undergrowth of the upper jaw, or a combination of the two. Like Class II issues, they can be genetically inherited and are treated much the same way.

Class III Skeleton
Skeletal

Class III Dental
Dental

  

Classification of Face

It is not sufficient to categorize orthodontic malocclusions by 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 (teeth):
This is an example of dental malocclusion that may require the removal of teeth for correction.

  

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

  

Class 2:

Maxillary Dental Protrusion — teeth
Maxillary Dental Protrusion  (teeth):
This is another form of dental malocclusion that may require the removal of teeth for correction.

  

Mandibular Retrognathism — jaws
Mandibular Retrognathism  (jaws):
The lower jawbone has not grown as much as the upper jawbone. This example of a Class II malocclusion demonstrates the need for early growth guidance.

  

Maxillary Dental Protrusion — teeth & Mandibular Retrognathism — jaws
Maxillary Dental Protrusion (teeth) &                 Mandibular Retrognathism  (jaws):
This combination of Class II malocclusions is more difficult to treat due to the skeletal disharmony. This may require orthognathic surgery in conjunction with orthodontic treatment.

Class 3:

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

  


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