On maxillary molars, which cusp is considered a functional cusp?

The lingual cusp of maxillary molars is considered the functional cusp because it plays a crucial role in occlusion during mastication. Functional cusps are primarily responsible for the proper alignment of teeth in relation to each other and for the effective chewing of food. In maxillary molars, the lingual cusp contacts the opposing teeth during the chewing cycle, which helps in the grinding and crushing of food. This contact facilitates a chewing action that is necessary for digestion.

In contrast, the buccal cusp tends to serve more of a supportive role and may not engage directly with the opposing dentition during normal chewing movements. The mesial and distal cusps also do not primarily serve functional roles in occlusion as they may not provide the necessary interdigitation for effective food processing. Hence, the lingual cusp is distinct in its functionality and importance in the overall occlusal relationship of the dental arch.