Christensen's phenomenon is seen in:: (A) Hinge movement., (B) Protrusive movement, (C) Lateral movement., (D) All of the above.
Answer is B. Protrusive movement occurs while incising and grasping food. This movement occurs after the condyles rotate for more than 13° in the TMJ. The mandible moves forwards and downwards, bringing the maxillary and mandibular anterior teeth in an edge-to-edge relation. The characteristic posterior separation seen during anterior protrusion is called 'Christensen's phenomenon.