TETH OGFGOF

1. Incisors

   • Appearance: Sharp, chisel-shaped teeth located at the front of the mouth. They have a single root.

   • Function: Used for cutting and slicing food into manageable pieces.

   • Number: 8 in total (4 in the upper jaw and 4 in the lower jaw).

2. Canines

   • Appearance: Pointed and cone-shaped with a single long root. Located next to the incisors.

   • Function: Designed for tearing and gripping food, especially meat.

   • Number: 4 in total (2 in the upper jaw and 2 in the lower jaw).

3. Premolars

   • Appearance: Broad and flat with ridges on the surface for grinding. Usually have one or two roots.

   • Function: Used for crushing and grinding food into smaller pieces.

   • Number: 8 in total (4 in each jaw).

4. Molars

   • Appearance: Large, flat teeth at the back of the mouth with a ridged surface. They have multiple roots.

   • Function: Specialized for grinding and crushing food into a paste for easier swallowing.

   • Number: 12 in total (including 4 wisdom teeth).

Enamel

• Definition: The outermost layer of the tooth, which is the hardest and most mineralized substance in the human body.

• Composition: Mainly composed of hydroxyapatite, a crystalline form of calcium phosphate (around 96% minerals, 4% water and organic material).

• Functions:

  • Protects the tooth from physical and chemical damage (e.g., acids from food and bacteria).

  • Prevents tooth sensitivity by shielding the inner layers.

  • Withstands high pressure during chewing.

• Interesting Fact: Enamel has no living cells, meaning it cannot repair itself if damaged.

2. Dentine (Dentin)

• Definition: The layer beneath the enamel that forms the bulk of the tooth structure.

• Composition: Around 70% minerals, 20% organic material (mainly collagen), and 10% water.

• Functions:

  • Supports the enamel and absorbs forces from chewing.

  • Contains microscopic tubules (dentinal tubules) that allow sensations (hot, cold, pain) to travel to the nerve.

  • Can regenerate to some extent by forming secondary dentine in response to damage.

• Interesting Fact: If enamel wears down, exposed dentine can cause tooth sensitivity.

3. Gum (Gingiva)

• Definition: The soft tissue that surrounds and protects the base of the teeth.

• Composition: Made up of connective tissue, blood vessels, and epithelial cells.

• Functions:

  • Provides a seal around the teeth to prevent bacteria from reaching deeper structures.

  • Supports the teeth and holds them in place along with the jawbone.

  • Helps absorb the forces of chewing and biting.

• Diseases:

  • Gingivitis: Inflammation of the gums caused by plaque buildup, leading to redness and bleeding.

  • Periodontitis: Severe gum disease where the gums recede, leading to potential tooth loss.

4. Pulp Cavity (Dental Pulp)

• Definition: The innermost part of the tooth containing soft tissue.

• Composition: Blood vessels, connective tissue, and nerves.

• Functions:

  • Supplies nutrients to the dentine through blood circulation.

  • Contains nerves that detect pain, temperature, and pressure.

  • Forms new dentine in response to injury (reparative dentine).

• Diseases:

  • Pulpitis: Inflammation of the pulp due to deep decay or trauma, leading to tooth pain.

  • If the pulp becomes infected, a root canal treatment may be needed to remove the infected tissue.

5. Cement (Cementum)

• Definition: A thin, bone-like layer that covers the root of the tooth.

• Composition: About 45–50% hydroxyapatite, with the rest being organic material and water.

• Functions:

  • Anchors the tooth root to the periodontal ligament.

  • Helps maintain the tooth's position within the jawbone.

  • Can regenerate slightly if damaged.

• Interesting Fact: Unlike enamel, cementum is more resistant to resorption (breaking down), helping to maintain tooth stability over time.

6. Nerve

• Definition: The bundle of nerve fibers inside the pulp cavity that transmits signals to the brain.

• Functions:

  • Detects pain from decay, injury, or extreme temperatures.

  • Helps regulate blood flow within the tooth.

  • Does not regenerate if damaged, meaning nerve death results in the loss of tooth sensation.

• Treatment for Nerve Damage:

  • If the nerve becomes severely infected, a root canal removes the nerve, but the tooth remains functional.

7. Fibres (Periodontal Ligament Fibres)

• Definition: A group of connective tissue fibers that attach the tooth to the surrounding jawbone.

• Functions:

  • Act as shock absorbers during chewing and biting.

  • Help detect pressure changes and adjust chewing force.

  • Allow minor movement of teeth to accommodate pressure.

• Interesting Fact: Orthodontic treatments (braces) work by slowly shifting teeth, which stretches or compresses these fibers, leading to bone remodeling.

8. Jawbone (Alveolar Bone)

• Definition: The part of the jaw that houses the sockets of the teeth.

• Composition: Compact and spongy bone with a rich blood supply.

• Functions:

  • Provides structural support for teeth.

  • Undergoes continuous remodeling depending on tooth movement and pressure.

• Diseases:

  • Osteoporosis can weaken the jawbone, leading to tooth loss.

  • Periodontal disease can cause bone resorption, making teeth loose.

Milk Teeth vs. Permanent Teeth

Milk Teeth (Primary Teeth)

• Total Number: 20 (10 in each jaw).

• Appearance: Begin erupting around 6 months and are fully present by 3 years.

• Functions:

  • Help in chewing and digestion.

  • Maintain space for permanent teeth.

  • Assist in speech development.

• Shedding: They gradually fall out between 6–12 years to be replaced by permanent teeth.

Permanent Teeth

• Total Number: 32 (16 in each jaw, including wisdom teeth).

• Functions:

  • Designed for stronger biting and chewing.

  • Meant to last a lifetime if properly cared for.

• Wisdom Teeth: The last set of molars, often removed due to space issues or impaction.

Use of Fluorides in Dental Health

• What is Fluoride?

  • A naturally occurring mineral that strengthens tooth enamel and prevents cavities.

• Sources:

  • Found in toothpaste, mouthwash, drinking water, and dental treatments.

• Functions of Fluoride:

  • Remineralizes enamel by replacing lost minerals.

  • Prevents acid attacks from bacteria in plaque.

  • Reduces tooth decay risk by making enamel more resistant.

• Fluoride Overuse:

  • Dental Fluorosis: A condition causing white spots on teeth due to excessive fluoride intake in early childhood.

Sources of Fluoride Pollution

a) Natural Sources

• Geological Activity: Some areas have high levels of fluoride in rocks, leading to natural contamination of groundwater.

• Volcanic Emissions: Volcanic eruptions release fluoride into the air and water sources.

b) Human-Made Sources

• Industrial Discharges:

  • Aluminum smelting, phosphate fertilizer production, and steel manufacturing release fluoride into air and water.

• Coal Burning:

  • Coal contains fluoride, and when burned, it releases fluoride gas into the atmosphere.

• Water Fluoridation:

  • While controlled fluoride levels in drinking water prevent tooth decay, excessive fluoride in water supplies can become harmful.

• Agricultural Runoff:

  • Phosphate fertilizers contain fluoride, which can leach into soil and water, affecting plants and animals.