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': 'Chronic fluoride toxicity results in: \nSelect and explain. \nA. Extreme arthritic changes of the spine resulting in rigidity, B. Calcification of the sheaths of muscles and tendons, C. Osteosclerosis, D. All of the above', 'role': 'user'}, {'content': "Answer: D \nExplanation: Chronic fluoride toxicity results from long-term ingestion of small amounts of fluoride.\xa0\nSevere pain in the backbones, joints, hip, stiffness in joints and spine.\xa0\nOutward bending of legs and hands is seen in advanced stages and these parts lose their shape and contours. This is called\xa0knock-knee syndrome.\nPregnant lactating mothers and children are the most vulnerable group.\xa0\nFluoride can also damage a fetus, if the mother consumes excess fluoride during pregnancy.\xa0\nCalcium fluoride seemed to be more toxic to the foetus than sodium fluoride.\xa0\nFluoride may lead to blocking and calcification of blood vessels causing cardiac problems.\xa0\nIn its severest form, ‘crippling fluorosis', the spine becomes rigid and the joints stiffen, virtually immobilizing the patient.\n\n\xa0\nRef : Soben peter 5th edition pg no:281", 'role': 'assistant'}]