This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
[{'content': "Christensen's phenomenon is seen in: \nSelect and explain. \nA. Hinge movement., B. Protrusive movement, C. Lateral movement., D. All of the above.", 'role': 'user'}, {'content': "Answer: B \nExplanation: 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.", 'role': 'assistant'}]