Which Angle Class is indicated when the MB cusp of the mandibular first molar occludes in the central fossa area of the maxillary first molar?

Which Angle Class is indicated when the MB cusp of the mandibular first molar occludes in the central fossa area of the maxillary first molar?

• A. Angle Class II
• B. Angle Class I
• C. Angle Class III
• D. Centric Contacts

Answer: (A)

This question tests how Angle’s molar relationship is defined by where the mesiobuccal cusp of the lower first molar fits on the upper first molar. In a normal Class I relationship, that cusp sits in the buccal groove of the upper first molar. When the MB cusp occludes in the central fossa of the maxillary first molar, the lower molar is positioned more posteriorly relative to the upper molar, which is the hallmark of Angle Class II (distocclusion). So the pattern described indicates a retruded mandible relationship or a relative overjet from the mandible’s perspective. Centric contacts refer to where teeth meet in centric occlusion and not to the molar class, and Class III would be the opposite (lower molar anterior to where it should be).

This question tests how Angle’s molar relationship is defined by where the mesiobuccal cusp of the lower first molar fits on the upper first molar. In a normal Class I relationship, that cusp sits in the buccal groove of the upper first molar. When the MB cusp occludes in the central fossa of the maxillary first molar, the lower molar is positioned more posteriorly relative to the upper molar, which is the hallmark of Angle Class II (distocclusion). So the pattern described indicates a retruded mandible relationship or a relative overjet from the mandible’s perspective. Centric contacts refer to where teeth meet in centric occlusion and not to the molar class, and Class III would be the opposite (lower molar anterior to where it should be).