Final answer:
The classification of occlusion of primary teeth includes Class I, Class II, Class III, and End-to-End Occlusion based on the relationship between the upper and lower teeth.
Step-by-step explanation:
Classification of occlusion of primary teeth is based on the relationship between the upper and lower teeth when the jaws are closed. There are four types of occlusion:
- Class I Occlusion: The upper first molar aligns with the lower first molar, and the other teeth fit together properly.
- Class II Occlusion: The upper first molar is positioned more forward than the lower first molar, resulting in the upper teeth protruding.
- Class III Occlusion: The lower first molar is positioned more forward than the upper first molar, resulting in an underbite where the lower teeth stick out in front of the upper teeth.
- End-to-End Occlusion: The upper and lower first molars touch each other directly without the presence of overbite or underbite.