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': "Down's syndrome is associated with all of the following except: \nSelect and explain. \nA. Retrognathia, B. Periodontal disease, C. Premature exfoliation of teeth, D. Retained deciduous teeth", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Skeletal ﬁnding is an underdeveloped mid-face, creating a prognathic occlusal relationship.\xa0\nOral\xa0ﬁndings include mouth breathing, open bite, appearance of macroglossia, ﬁssured lips and tongue,\xa0angular cheilitis, delayed eruption times, missing and malformed teeth, oligodontia, small roots,\xa0microdontia, crowding, and a low level of caries.\xa0\nChildren with Down syndrome experience a high\xa0incidence of rapid, destructive periodontal disease, which may be related to local factors such as tooth morphology, bruxism, malocclusion, and poor oral hygiene.\xa0\n\nPediatric Dentistry / Shobha Tandon - 2nd Ed', 'role': 'assistant'}]