Sunday, January 4, 2009

Teeth Care






Types of teeth





The shapes of animals' teeth give clues to the type of diets theve sharp, pointed teeth to pierce and tear. Plant eaters have broad, flat teeth to crush and grind. Humans are no exception. As a species, we eat both meats and plants, so we have different types of teeth to handle both types of food.







1. Incisors


The four front teeth in both your upper and lower jaws (a total of eight) are incisors. The pair of teeth at the center of your mouth, top and bottom, are called the central incisors. And the teeth on each side of the central incisors are the lateral incisors. All the incisors are broad, flat teeth with a narrow edge good for cutting or snipping off pieces of food. They have a single root








2. Canines


On both sides of your upper and lower incisors are the canines (a total of four). Sometimes called eyeteeth or cuspids, canines are the longest and most stable teeth in the mouth. They are thick and come to a single sharp point. They are ideal for ripping and tearing at foods that might be tough, such as meat, and for piercing and holding. They have a long single root.




3. Premolars

Next to each canine are two premolars (a total of eight). Also called bicuspids, premolars are a cross between canines and molars. They have sharp points for piercing and ripping, but they also have a broader surface for chewing and grinding. On the upper jaw, the first premolars (directly next to the canines) have two roots, and the second premolars have one root. On the lower jaw,all premolars have one root.



4. Molars


The last three upper and lower teeth on both sides of your mouth are the molars (a total of 12). They are numbered first, second or third molars depending on their location. The first molars, also called 6-year molars, are those closest to the front of the mouth, directly next to the second premolars. The third molars are also called the wisdom teeth. They are the last teeth, farthest back in the mouth on all sides. In between are the second molars, also called 12-year molars. Molars are large teeth with broad surfaces designed for crushing, grinding and chewing food. On the upper jaw, the molars have three well-separated roots. On the lower jaw, the molars have two roots.