Phossy jaw is caused by-

Ans. is 'a' i.e., White Phosphorus o Phossy jaw is caused by phosphorus poisoning. All phosphorus poisoning are caused by white (yellow) phosphorus (Red phosphorus is nontoxic).Phosphorus poisoningo Phosphorus is a protoplasmic poison affecting cellular oxidation and causing anoxic necorbiosis, classically affecting liver. It increases fat deposition and inhibits glycogen deposition in liver. It is used in fire works (Diwali poisoning) and as rat poison. Lethal dose is 60-120 mg.o Phosphorus occurs in two formsWhite/yellow phosphorus: It is white, and becomes yellow on exposure to air. It is translucent, waxy, luminous and crystalline cylinders. It has garlic like odor. It is insoluble in water and luminous in dark. Its fumes show phosphorescence.Red phosphorus : It is reddish brown, inert, odourless and tasteless. It is nontoxic (thus poisoning occurs only due to white phosphorus). It is put on the sides (striking surface) of match box (along with powdered galss).Acute poisoningo It has following stages :1st Stage <GI irritation): There is nausea, vomiting, diarrhea and garlic odor. This stage lasts for 8 hours to 3 days.2nd Stage (Asymptomatic): This stage lasts for 3 days.3rd Stage : There is liver and kidney damage due to absorbed phosphorus. Initially liver is enlarged due to acute fatty infiltration. Later liver shruks due to necrosis, i.e. acute yellow atrophy.Chronic poisoningo Toothache is the first symptom which is associated with loosening of teeth, necrosis of gums and osteomyelitis of jaw. Therefore chronic phosphorus poisoning is also know as phossy jaw (or glass jaw).Postmortem appearanceo There is garlic odor. Viscera and stool glow in dark (due to luminosity).o To preserve luminosity, viscera are preserved in saturated saline solution. Rectified spirit is not used as it causes loss ofluminosity.