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': 'Most common method to establish occlusal vertical dimension \nSelect and explain. \nA. Niswonger’s method, B. Neuromuscular perception, C. Phonetics, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (i) Niswonger’s method (physiologic rest position)\xa0\nThis is the most commonly used method to establish occlusal vertical\xa0dimension. It uses the physiologic rest position (vertical dimension at\xa0rest) to determine the occlusal vertical dimension. As discussed\xa0previously in this chapter, Niswonger stated that:\nVD at Occlusion = VD at rest – freeway space (2–4 mm)\nHence, the physiologic rest position is first determined. The\xa0contoured maxillary occlusal rim is placed in the patient’s mouth and\xa0the vertical dimension at rest is determined using facial measurements as discussed previously. The mandibular occlusal rim is then inserted\xa0and it is trimmed and contoured until it meets the maxillary rim\xa0evenly. The lower rim is adjusted till the facial measurement in occlusion is 2–4 mm less than that in rest position. This will provide\xa0for the necessary interocclusal space or freeway space. The\xa0same can be verified, by asking the patient to part the lips without moving the jaws at rest position, with the occlusal rims inserted.', 'role': 'assistant'}]