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 I

Maxillary-Mandibular Dental Protusion – teeth

Maxillary-Mandibular Dental Retrusion – teeth
 


This is an example of a dental malocclusion that may require the removal of teeth for correction.

This is an example of a dental malocclusion that may be treated with expansion rather than removing teeth.

Class II

Maxillary Dental Protrusion – teeth

Mandibular Retrognathism – jaws

Maxillary Dental Protrusion – teeth
Mandibular Retrognathism – jaws
 
 

This malocclusion may require the removal of teeth.

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

These Class II maloclusions are more difficult to treat due to the skeletal disharmony and may require orthognathic or jaw surgery in conjunction with orthodontic treatment.

Class III

Mandibular Dental Protrusion – teeth

Mandibular Prognathism – jaws
 

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 teeth due to the dental protrusion

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 or jaw surgery in conjunction with orthodontic treatment.