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': 'Which of the following is recommended for bilateral\npremature exfoliation of mandibular canines? \nSelect and explain. \nA. Nance appliance, B. Lingual arch, C. Band and loop, D. Distal shoe appliance', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Fixed Lingual Arch/Lingual Holding Arch\nThis is a non-functional, passive fixed space maintainer.\nIndications:\n\nWhere there is bilateral loss of deciduous molars, a\xa0fixed lingual arch is often most satisfactory.\nMultiple loss of primary teeth in the mandibular arch.\xa0\n\nRemovable distal shoe space maintainer\xa0\nThis is devised by Starkey. It is indicated in unilateral or bilateral early loss of primary second molar before the eruption of permanent first molar.\nNance space holding appliance is a non-functional passive type of fixed space maintainer. It is used in maxillary arch for bilateral space maintenance.\nBand and bar, band and loop, band or crown and loop maintainer, cantilever maintainer to prevent the mesial migration of the first permanent molar.', 'role': 'assistant'}]