Who was Dr. Angle?

Considered the ‘father of orthodontics,’ Dr. Angle was the first to develop a classification system for orthodontics. According to Dr. Angle, the first molars were the foundation of the arches.

The classification system therefore is based off the relationship between the first molars – more specifically, the spatial relationship between the mesiobuccal cusp of the maxillary first molar and the mesiobuccal groove of the mandibular first molar.

Class I Occlusion

In a Class I occlusion, the mesiobuccal cusp of the maxillary first molar sits in the mesiobuccal groove of the mandibular first molar.

Class I occlusion is seen in 70% of malocclusions, and is the most common type of malocclusion.

In the example, notice the blue lines. These indicate the relationship between the mesiobuccal cusp and mesiobuccal groove.

Class II Occlusion

In Class II occlusion, the mesiobuccal cusp of the maxillary first molar sits mesial to the mesiobuccal groove of the mandibular first molar.

There are two divisions of a Class II occlusion. The first division has a characteristic appearance – upper incisors flared forward.

The second division also has a characteristic appearance. Instead of the upper incisors flaring forward, they are flared lingual. As a result, the lateral inciors are flared labially (forward).

Class III Malocclusion

The rarest of malocclusions (composing of ~5% of malocclusions), the Class III malocclusion appears with the mesiobuccal cusp of the maxillary first molar distal to the mesiobuccal groove of the mandibular first molar.

(n.d.) Orthodontic Vocabulary. Dr. Waxler. A.T. Still Missouri School of Dentistry and Oral Health.

(1970, January 1). Special Collections. Retrieved from https://speccoll.library.arizona.edu/collections/correspondence-edward-h-angle