Which term describes occlusal interference that occurs when there is contact between the maxillary and mandibular posterior teeth on the same side as the direction the mandible has moved?

• A. Working occlusal interference
• B. Non-working occlusal interference
• C. Centric occlusal interference
• D. Occlusal trauma

Answer: (A)

When the jaw moves laterally, the posterior teeth on the side toward which the mandible moves can contact prematurely and hinder that movement. That premature contact on the moving or working side is called a working occlusal interference. In this scenario, the contacts occur between the maxillary and mandibular posterior teeth on the same side as the movement direction, which fits this definition. If the contacts were on the opposite, non-working side during the excursion, it would be a non-working interference; references to centric occlusion describe premature contacts in the centric position, and occlusal trauma refers to damage from excessive forces, not the direction-specific interference during movement.