An air pollutant is a substance in the air that can have adverse effects on humans and the ecosystem. The substance can be solid particles, liquid droplets, or gases. A pollutant can be of natural origin or man-made. Pollutants are classified as primary or secondary.
How is gum graft surgery performed? During gum grafting surgery, a periodontist will commonly take connective tissue from the roof of the mouth (palate) and suture it to the affected gumline. This allows more tissue to grow and close the exposed root surface (gum recession).
You lick or bite your lip. Nervously licking your lips exposes them to your mouth's digestive enzymes, said Dr. Whitney Bowe, a New York board-certified dermatologist. These enzymes chew away at the skin and can lead to dermatitis and cheilitis (inflammation), which make lips appear dry and cracked, she said.