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 12 year old male patient complains of pain in  upper front teeth region and gives a history of fall while playing 30 minutes ago. Intra-oral examination reveals intrusion of maxillary right central incisor by 8 mm. What is the most appropriate treatment for this patient? \nSelect and explain. \nA. Allow the tooth to erupt without intervention., B. Reposition surgically and stabilize for 4 to 8 weeks  by means of a flexible splint with endodontic intervention., C. If no movement is evident after 2 to 4 weeks, the tooth may be repositioned either orthodontically  or  surgically with endodontic intervention., D. If no movement is evident after 2 to 4 weeks, the tooth may be repositioned either orthodontically  or  surgically without endodontic intervention.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The treatment for a permanent tooth with a closed root end, and intruded less than 3 mm, is to allow the tooth\xa0to erupt without intervention. If no movement is evident after 2 to 4 weeks, the tooth may be repositioned either\xa0orthodontically\xa0 or\xa0 surgically\xa0 before\xa0 ankylosis\xa0 can\xa0 take place. If the tooth is intruded 7 mm or more, the tooth\xa0is repositioned surgically and stabilized for 4 to 8 weeks by means of a flexible splint. In most instances the pulp\xa0will become necrotic with intrusive injuries in teeth with complete root formation. Root canal treatment should be\xa0initiated, with calcium hydroxide as a temporary canal- filling material, 2 to 3 weeks after stabilization.\xa0\nThe treatment for an intruded permanent tooth with incomplete\xa0 root\xa0 formation\xa0 is\xa0 to\xa0 allow\xa0 it\xa0 to\xa0 erupt\xa0 spontaneously. If no movement is seen within a few weeks, orthodontic\xa0 repositioning\xa0 should\xa0 begin.\xa0 If\xa0 the\xa0 tooth\xa0 is intruded 7 mm or more, the tooth can be repositioned surgically\xa0 and\xa0 stabilized\xa0 by\xa0 means\xa0 of\xa0 a\xa0 flexible\xa0 splint. Endodontic therapy is often required, however, and the tooth\xa0 should\xa0 be\xa0 monitored\xa0 closely\xa0 while\xa0 a\xa0 decision\xa0 on endodontic therapy is pending.', 'role': 'assistant'}]