True regarding fluorosis are all except
**Fluorosis Core Concept**
Fluorosis is a condition caused by excessive intake of fluoride, leading to dental and skeletal abnormalities. It occurs due to the accumulation of fluoride ions in the body, which can cause damage to the teeth and bones. The primary sources of fluoride are fluoridated toothpaste, fluoridated water, and certain industrial processes.
**Why the Correct Answer is Right**
Fluorosis is characterized by the deposition of fluorapatite, a type of apatite that contains fluoride ions, in the teeth and bones. This leads to an increase in the density and hardness of the teeth, but also causes them to become more prone to decay. In severe cases, fluorosis can cause skeletal abnormalities, such as osteosclerosis and bone deformities. The pathophysiology of fluorosis involves the inhibition of enzymes involved in the hydroxylation of collagen, leading to an accumulation of unhydroxylated collagen fibrils.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because fluorosis is not caused by a deficiency of fluoride. In fact, excessive intake of fluoride is the primary cause of fluorosis.
**Option B:** This option is incorrect because fluorosis does not lead to a decrease in the density and hardness of the teeth. Instead, it causes an increase in these properties.
**Option C:** This option is incorrect because fluorosis can cause skeletal abnormalities, such as osteosclerosis and bone deformities, in severe cases.
**Clinical Pearl / High-Yield Fact**
Fluorosis is a dose-dependent condition, meaning that the severity of the condition increases with the amount of fluoride ingested. Therefore, it is essential to monitor fluoride intake, especially in children, to prevent the development of fluorosis.
**Correct Answer: A. This option is incorrect because fluorosis is not caused by a deficiency of fluoride.**