Angle’s Classification of Occlusion
The three classes according to Angle’s classification are as follows: Normal occlusion: The mesiobuccal cusp of the upper first molar occludes with the buccal groove of the lower first molar. Class I malocclusion: Same as normal occlusion but characterized by crowding, rotations, and other positional irregularities. Class II malocclusion: The mesiobuccal cusp of the upper first molar occludes anterior to the buccal groove of the lower first molar. There are two subtypes of Class II malocclusion. Class II, division 1: Upper incisors are tilted outwards, creating significant overjet. Class II, division 2: Upper incisors are labially inclined. Class III malocclusion: The mesiobuccal cusp of the upper first molar occludes posterior to the buccal groove of the lower first molar.