Which cusps contact the opposing teeth during functional occlusion to help maintain vertical dimension in the posterior region?

• A. Functional Cusps
• B. Non-functional Cusps
• C. Centric Contacts
• D. Curve of Spee

Answer: (A)

Functional cusps engage the opposing dentition during normal bite, bearing the primary occlusal load. In the back teeth, the buccal cusps of the upper row and the lingual cusps of the lower row are the ones that fit into the opposing teeth’s grooves and fossae when the jaw closes in centric occlusion. Their contact provides stable interlocking support and helps preserve the vertical dimension of the posterior bite, preventing collapse of height when the teeth come together.

Non-functional cusps don’t contact in centric occlusion; they mainly participate during lateral or protrusive movements to guide the mandible and manage guidance rather than support vertical height. The Curve of Spee describes the sagittal curve of the occlusal plane and influences occlusion and mechanics, but it doesn’t specify which cusps contact in functional occlusion.