Advanced Dental Admission Test (ADAT)

What is a characteristic of Class I occlusion?

1. The mb cusp of the max first molar contacts the mesial groove of the mandibular first molar

2. The mb cusp of the max first molar contacts the distally of the mandibular first molar

3. Max canine contacts between the opposing mandibular canine and first molar

4. The mb cusp of maxillary molars contacts the buccal grooves of opposing molars

The correct answer is: The mb cusp of the max first molar contacts the mesial groove of the mandibular first molar

Class I occlusion, also known as neutroclusion, is characterized by specific relationships between the first molars of both jaws. In this class of occlusion, the mesiobuccal cusp (mb cusp) of the maxillary first molar fits into the mesial groove of the mandibular first molar. This relationship is fundamental to Class I occlusion, as it establishes a stable interdigitation that is typically seen in a well-aligned dentition. The importance of this relationship is that it allows for proper alignment and functional interaction during the dental occlusion, which means that the teeth can come together in a way that supports efficient chewing and contributes to overall dental aesthetics and function. It also indicates that the bite is ideally positioned concerning physiological and mechanical parameters, which is crucial for the health of the jaw joints and masticatory muscles. The other choices describe different relationships that would suggest a deviation from Class I occlusion, leading to either Class II or Class III occlusions.