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: Pathology
[{'content': "Marie and Sainton's disease is also known as: \nSelect and explain. \nA. Dentinogenesis imperfecta., B. Cleidocranial dysostosis., C. Turners hypoplasia., D. Amelogenesia imperfecta.", 'role': 'user'}, {'content': "Answer: B \nExplanation: Important Mainfestations of cleidocranial dysostosis or\xa0Marie and Sainton's disease:\n\nPartial or complete absence of clavicles.\nDelayed closure of fontanelle.\nWormian bones are common.\nThe sagittal suture is characteristically sunken, giving the skull a flat appearance.\nHypoplasia of maxilla.\nProlonged retention of deciduous teeth (AP-14) and subsequent delay in eruption of succedaneous teeth.\nAbsence or paucity of cellular cementum on the roots of the permanent teeth with no increased thickening of the primary acellular cementum.", 'role': 'assistant'}]