STUDY THE DIFFERENT TYPES OF TEETH AND IT'S FUNCTION

chingpherd (63)in #science • 8 years ago

The teeth are a group of hard organs found in the oral cavity. We use teeth to masticate (or chew) food into tiny pieces. They also provide shape to the mouth and face and are important components in producing speech.

A tooth can be divided into two main parts: the crown and root. Found above the gum line, the crown is the enlarged region of the tooth involved in chewing. Like an actual crown, the crown of a tooth has many ridges on its top surface to aid in the chewing of food. Below the gum line is the region of the tooth called the root, which anchors the tooth into a bony socket known as an alveolus

Roots are tapered structures resembling the roots of plants, and each tooth may have between one to three roots. The exterior surface of the root is covered in a bone-like mixture of calcium and collagen fibers known as cementum. Cementum provides grip for the periodontal ligaments that anchor the root to the surrounding alveolus.

Mastication, or chewing, is the main function of the teeth. The teeth are aligned in the jaws so that the peaks of one tooth align with the valleys of its counterpart on the other jaw. Every bite forces food into the interface of the teeth to be chopped, while lateral motion of the jaw is used to grind food in the premolars and molars.

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Each tooth is an organ consisting of three layers: the pulp, dentin, and enamel.

The pulp of the tooth is a vascular region of soft connective tissues in the middle of the tooth. Tiny blood vessels and nerve fibers enter the pulp through small holes in the tip of the roots to support the hard outer structures. Stem cells known as odontoblasts form the dentin of the tooth at the edge of the pulp.

Surrounding the pulp is the dentin, a tough, mineralized layer of tissue. Dentin is much harder than the pulp due to the presence of collagen fibers and hydroxylapatite, a calcium phosphate mineral that is one of the strongest materials found in nature. The structure of the dentin layer is very porous, allowing nutrients and materials produced in the pulp to spread through the tooth.

The enamel — the white, outer layer of the crown — forms an extremely hard, nonporous cap over the dentin. Enamel is the hardest substance in the body and is made almost exclusively of hydroxylapatite.

What Are the Different Parts of a Tooth?

Crown— the top part of the tooth, and the only part you can normally see. The shape of the crown determines the tooth's function. For example, front teeth are sharp and chisel-shaped for cutting, while molars have flat surfaces for grinding.

Gumline— where the tooth and the gums meet. Without proper brushing and flossing, plaque and tartar can build up at the gumline, leading to gingivitis and gum disease.

Root— the part of the tooth that is embedded in bone. The root makes up about two-thirds of the tooth and holds the tooth in place.

Enamel— the outermost layer of the tooth. Enamel is the hardest, most mineralized tissue in the body — yet it can be damaged by decay if teeth are not cared for properly.

Dentin— the layer of the tooth under the enamel. If decay is able to progress its way through the enamel, it next attacks the dentin — where millions of tiny tubes lead directly to the dental pulp.

Pulp— the soft tissue found in the center of all teeth, where the nerve tissue and blood vessels are. If tooth decay reaches the pulp, you usually feel pain.

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Teeth are classified into four major groups: incisors, canines, premolars, and molars.

Incisors are chisel-shaped teeth found in the front of the mouth and have a flat apical surface for cutting food into smaller bits.

Canine teeth, also known as cuspids, are sharply pointed, cone-shaped teeth that are used for ripping tough material like meat. They flank the incisors on both sides.

Premolars (bicuspids) and molars are large, flat-surfaced teeth found in the back of the mouth. Peaks and valleys on the flat apical surface of premolars and molars are used for chewing and grinding food into tiny pieces.

Molars— used for grinding, these teeth have several cusps on the biting surface.

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Tooth decay and cavities are important health concerns related to the teeth. The enamel that covers the crown in each tooth can be broken down by acids produced by bacteria that live in the mouth and assist in digestion of small bits of food. This process of enamel erosion by acids is called decay. To prevent decay, good oral hygiene, consisting of daily brushing and flossing, is necessary. Decay can eventually lead to cavities, also known as dental caries, where holes appear in the enamel and expose the dentin. Cavities require medical intervention to prevent their growth, usually resulting in the removal of the affected tissue and the filling of the cavity with a hard material to restore the strength and function of the tooth.

What is tooth decay?

Tooth decay
is damage that occurs when germs (bacteria) in your mouth make acids that eat away at a tooth. It can lead to a hole in the tooth, called a cavity. If not treated, tooth decay can cause pain, infection, and tooth loss.

A tooth has three layers.

The hard outer layer is called enamel.
The middle layer is called dentin.
The center of the tooth is called the pulp. It contains nerves and blood vessels.

The more layers that are affected by decay, the worse the damage.

What causes tooth decay?

Bacteria and food can cause tooth decay. A clear, sticky substance called plaque is always forming on your teeth and gums. Plaque contains bacteria that feed on the sugars in the food you eat.

As the bacteria feed, they make acids. The acids attack the teeth for 20 minutes or more after you eat. Over time, these acids destroy tooth enamel, causing tooth decay.

Things that make you more likely to have tooth decay include:

Not brushing and flossing your teeth regularly and not seeing a dentist for checkups and cleanings.
Eating foods that are high in sugar and other carbohydrates, which feed the bacteria in your mouth.
Not getting enough fluoride. Fluoride helps prevent tooth decay by making teeth more resistant to acids produced by plaque. Fluoride is added to many public water supplies.
Not having enough saliva. Salivawashes away food and harmful sugars, so it helps protect your teeth from decay. A dry mouth may be caused by a condition such as xerostomia or Sjögren's syndrome, by taking certain medicines, or by breathing through your mouth. Older adults are more likely to have a dry mouth.
Having diabetes.
Smoking, using spit (smokeless) tobacco, or breathing secondhand smoke.

How can you prevent tooth decay?

You can prevent most tooth decay with these tips:

Take good care of your teeth. Brush your teeth twice a day, in the morning and before bedtime. Use fluoride toothpaste. Floss once a day.

See your dentist for checkups once or twice a year so problems can be found before they're serious.

Don't snack before bedtime. Food left on the teeth overnight is more likely to cause cavities.

Avoid foods that have a lot of sugar, especially sugar-coated cereals, desserts, and sticky foods like taffy and raisins. The longer sugar is in contact with your teeth, the more damage it will do.

How is it treated?

The best treatment for tooth decay depends on how severe it is. If tooth decay is caught early, before a cavity forms, you may be able to stop it by brushing with fluoride toothpaste or getting fluoride treatments. That's one good reason to see your dentist on a regular basis.

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