Wednesday, April 19, 2006

More Than You Want To Know About A Tooth

An extremely boring artical...mainly about the periodontal ligament. One of my front teeth was jarred out of place, when I bit down at the wrong angle. It is loose, and kinda sticks out at a forward angle. This is limiting my diet to soup and soft foods, and is painful when I bite down on it, so naturally I looked on Google to see what's up. From what I read here, the tooth will kinda fuse back into place, if I can keep from wiggling it. I do think that a dentist is in order here, as I would love to chew on something, like a burrito or a pizza.

A tooth consists of four parts:
Pulp... Dentin... Enamel... Cementum

There is a connective tissue that surrounds and holds the root in the jaw socket. This tissue is called the periodontal ligament.

Pulp is the innermost layer of a tooth. It consists of connective tissue, blood vessels and nerves. The blood vessels nourish the tooth and nerves transmit sensations of pain to the brain.

The pulp has two parts, the pulp chamber and the root canal. The pulp chamber lies in the crown of the tooth. The portion of a tooth that rises above the gum is the crown and the portion below it is called the root. The root canal lies in the root of the tooth. Blood vessels and nerves enter the root canal through a small hole at the tip of the root. They extend through the root canal and into the pulp chamber.

Dentin is a hard, yellow substance that surrounds the pulp. It makes up most of a tooth. Dentin is harder than bone. It consists mainly of mineral salts and water but also has some living cells.

Enamel lies over the dentin in the crown of the tooth. It forms the outermost covering of the crown. Enamel is the hardest tissue in the body. It enables the tooth to withstand the pressure placed on it during biting and chewing. Enamel consists of mineral salts and a small amount of water. Enamel is white but transparent. The yellow colour of the dentin shows through the enamel, and so most teeth appear slightly yellowish.

As a person grows older, small amounts of enamel begin to wear away. This process is called attrition and occurs as a result of long-term use of teeth.

Cementum overlies the dentin in the root of the tooth. In most cases, the cementum and the enamel meet where the root ends and the crown begins. As the surface wears away, the tooth grows farther out of its socket, exposing the root. These areas may then become more sensitive to hot and cold liquids. Cementum is as hard as bone and consists mainly of mineral salts and water.

Periodontal Ligaments

The periodontal ligaments are considered part of the periodontium, as they are supporting tissue of a tooth. These ligaments are a specialized connective tissue that attach teeth from the cementum to the surrounding alveolar bone. They are about .2 millimeters in width, which decreases with age.

Since teeth are not embedded in bone directly, large compressive forces can occur on teeth without destruction of the bone. Instead, the tooth, pulling downward on the periodontal ligaments, create tension which is actually the stimulus for bone growth.

Another function of the periodontal ligaments is to serve as a method for sensation. There are receptors within the periodontal ligaments which sense differing amounts of tension. This helps the body discern the amount of force being placed on a tooth, during chewing for example, because enamel has no sensory receptors itself.

The periodontal ligament has fibers composed of Type I and Type III collagen. Compared to most other ligaments of the body, these are highly vascularized.

Collagen is the main protein of connective tissue in animals and the most abundant protein in mammals, making up about 40% of the total. It is one of the long, fibrous structural proteins whose functions are quite different from those of globular proteins such as enzymes. It is tough and inextensible, with great tensile strength, and is the main component of cartilage, ligaments and tendons, and the main protein component of bone and teeth. Along with soft keratin, it is responsible for skin strength and elasticity, and its degradation leads to wrinkles that accompany aging. It strengthens blood vessels and plays a role in tissue development. It is present in the cornea and lens of the eye in crystalline form. It is also used in cosmetic surgery — for example lip enhancement — although hyaluronic acid is now often used instead.

If anybody read this, I appologise, but It's a good place to store my information...
I warned you...It's a ~~~BORING~~~ artical.

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