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 a feature of Class I type 3\nmalocclusion? \nSelect and explain. \nA. Posterior crossbite, B. Anterior crossbite, C. Mesial drifting of molars, D. Protrusion of mandibular incisors', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Dewey (1915) divided Angle’s class I into five types and Angle’s class III into three types. There were no modifications for class II. He considered the same molar relationship as in Angle’s classification.\nModifications of class I malocclusion\nType I -\xa0Crowded anterior teeth\nType II -\xa0Maxillary incisors in labioversion\nType III -\xa0Anterior cross-bite\nType IV -\xa0Posterior cross-bite\nType V -\xa0Molars are in mesioversion\xa0due to shifting following loss of a tooth anterior to the first molars; all other teeth are in a normal relationship.\nReference: Orthodontics: Diagnosis and Management of Malocclusion and Dentofacial Deformities 3rd O P Kharbanda, pdf no 333', 'role': 'assistant'}]