Iodine in biology ring iodine atom, and also convert T3 to 3,3'-Diiodothyronine (T2) by removing an inner ring atom. Both of the latter products are inactivated hormones which have essentially no biological effects and are quickly prepared for disposal. A family of non-selenium-dependent enzymes then further deiodinates the products of these reactions. Selenium also plays a very important role in the production of glutathione, the body's most powerful antioxidant. During the production of the thyroid hormones, hydrogen peroxide is produced in large quantities, and therefore high iodine in the absence of selenium can destroy the thyroid gland (often described as a sore throat
Parotid gland mucosa with sphinterotomy may allow removal; however, if situated more posteriorly within the main duct, complete gland excision may be necessary. The parotid salivary gland can also be pierced and the facial nerve temporarily traumatized when an inferior alveolar local anesthesia nerve block is incorrectly administered, causing transient facial paralysis. About 80% of tumors of the parotid gland are benign. The most common of these include pleomorphic adenoma (70% of tumors, affecting predominantly females (60%)) and Warthin tumor (i.e. adenolymphoma) more in males than in females. Their importance is in relation to their anatomical position and tendency to grow over