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 10 year old male patient complains of a gap between his upper front teeth. Intra-oral examination reveals a midline diastema of 2 mm, for which a removable appliance with finger springs was given. What type of anchorage is seen with this appliance? \nSelect and explain. \nA. Reciprocal, B. Simple, C. Intramaxillary, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: A small but unesthetic diastema (2 mm or less) can be closed in the early mixed dentition by tipping the central incisors together. A maxillary removable appliance with clasps, fingersprings, and possibly an anterior bow will successfully complete this type of treatment.\nReciprocal anchorage: Reciprocal tooth movement is produced when two teeth or resistance units of equal size pull against each other, as in this example of the reciprocal closure of a maxillary midline diastema.\nSimple anchorage: Resistance of the anchorage unit to tipping. Closure of a midline diastema can be accomplished with a removable appliance and fingersprings to tip the teeth mesially.\nIntramaxillary\xa0anchorage:\xa0When the anchor units and the reactive units are in the same arch.', 'role': 'assistant'}]