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': 'A 20\xa0year old female patient\xa0complains of lower teeth irregularities and wants to undergo orthodontic treatment without undergoing extractions. On examination, moderate lower incisor crowding was noted. Bolton’s analysis reveals an overall mandibular excess of 4 mm and anterior mandibular excess of 2 mm. Which of the following teeth can be selected for interproximal reduction in this patient? \nSelect and explain. \nA. Upper anteriors, B. Lower anteriors, C. Upper posteriors, D. Lower anteriors and posteriors', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Bolton’s analysis considers the ratio of the tooth material of the maxillary arch to the mandibular arch. The combined and individual widths of maxillary and mandibular teeth have a pre-determined proportion to maintain normal occlusion relationship. An alteration in this balance would lead to unsatisfactory occlusion. If there is a maxillary tooth material excess, then it would lead to a large overjet, whereas if there is a mandibular excess, it will lead to crowding or negative overjet.\nClinical Application:\n\nOverall excess of 4 mm in the lower arch with a lower anterior excess of 4mm indicates stripping in the lower 3-3 region.\xa0\nOverall excess of 4 mm in the lower arch with normal ant ratio indicates stripping in the lower posteriors.\nOverall excess of 4 mm in the lower arch with a lower anterior excess of 2 mm indicates interproximal reduction in all the lower teeth.', 'role': 'assistant'}]