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Sunday, November 15, 2009

Periodontal disease:



Don't let the weird name tick you off. "Periodontal" is Latin for "around the tooth" and this essay will examine the disorders in this region.

Periodontal disorders can be divided into two groups or stages: the first is gingivitis and the second is periodontis.  

Plaque – a thin layer of bacteria which forms on our teeth – starts this disorder. If oral hygiene is not adequately considered, these bacteria will continue to grow and at the gum level, it will cause the gums to swell and become red. This is the mild or silent stage which is called gingivitis and is usually painless.

But if the bacteria keep on growing, and brushing and flossing doesn't come in to stop it, the bacteria will start eating into the gum. This will cause a space between the tooth and the gum which is called a periodontal pocket. Bacteria will fill this tiny hole and start to expand it. Gradually they will eat into the periodontal ligaments and the alveolar bone. The overall result will be the loss of the tooth attachment to the bone and finally the loss of the tooth. This second stage is called periodontis, which unlike gingivitis is very painful. Apart from the swelling and redness of the gums, the gums will bleed with a slight brush   

 Causes:

The main cause of periodontal disorders is plaque, but the few listed bellow also play a role:

 1) Smoking:

Smoking is a terribly bad habit and here's another point to add to the list of the reasons. A study showing two groups of people over the age of 65 – one group of smokers and the other of non-smokers – concluded that of the non-smokers, 20% were toothless but a whopping 42% of the smokers were bold in the mouth.
The main reason is calculus – the plaque which hardens on the tooth. Smokers usually need a dentist's assistance every few months in removing the calculus. But if it's not removed, the same story as mentioned above will occur. Apart from the calculus, the existence of poisonous and dangerous material (such as formaldehyde and cadmium which are also causes of cancer), increase the speed of the process slightly.
Also, if a smoker decides to treat the disease, the time it will take for the tissue to heal is longer than in a non-smoker.

 2) Maturity and Pregnancy in women:

In the maturity stage of a female's life, because of high secretion of sexual hormones (estrogen and progesterone), the blood circulation is at a higher rate. This means that body tissues - including the gum – will be receiving more blood and therefore being more sensitive. So it is recommended by dental hygienists to take oral hygiene seriously in this stage as a smaller amount of bacteria could start the process of periodontal diseases. Also, the infection could enter the blood and circulate, spreading the bacteria to other parts of the body.

Researches show that during the third and eighth month of pregnancy, the female's gum could become red and swollen. And a severe reaction by the immune system could cause lumps on the gum line called tumors. But these aren't causes of cancer, are painless and will disappear by themselves; but in cases which the tumor doesn't stop growing, they are removed by dentists. Observations show that pregnant women with periodontal disease are seven times more likely than those with a healthy periodontum (gum, periodontal ligaments and alveolar bone) to deliver pre-term and to low weight babies.

 3) Diet:

This is also an important factor. For example vitamin C, apart from having antioxidant characteristics has the role of maintaining the form of tissues.

Other factors such as stress, genetics, other bodily disorders (heart disease, diabetes, pancreatic cancer,…) and a few more are also in some way connected to periodontal disease.

Sunday, November 8, 2009

Tooth: the structure

Teeth are white and hard tissues in our body that we donate to the tooth fairy.

First off, teeth are lined up in two separate lines. The upper line is called the maxilla and the lower one is called the mandible. The development of teeth starts during the pregnancy period. In the last three months of an embryo's stay in its mother, the teeth become calcified – using the minerals which the mother consumes through the umbilical cord. 

The eruption of teeth usually starts from 6 months after birth. The first set – which are called the milk teeth / baby teeth / deciduous teeth or primary teeth – and consist of 20 teeth (10 in the maxilla and 10 in the mandible), all rise till the age of 2 years. From then on these teeth start to fall and give their spots to more mature biters called Secondary teeth or Permanent teeth. Permanent teeth are 28 (14 in the maxilla and 14 in the mandible). 




The period in which the mouth consists of both Primary and Secondary teeth, is called the mixed stage. The permanent teeth are usually completely erupted by the age of 12. This just leaves 4 more teeth called the wisdom teeth. These four usually erupt by the age of 18, but in some people in later years and even never in others.

The lining of the Primary teeth just has one less pre-molar, one less molar and no wisdom tooth on every quarter of the mouth:


Now that we have a good imagination of teeth, let's take a look at the structure of a single tooth.

1)      The external structures: the Crust which is the white thing of a tooth we see above the gum. Whatever is under the gum is called the Root.

2)      The internal structures: the pulp is the part of the tooth which the blood vessels and neurons/ nerves run through. Dentine is the stuff which surrounds the pulp. These two are in the Root section. The enamel is the white part we see when we open our mouth. So most of the crust is taken up by enamel and only a tiny fraction is covered by dentine. Cementum is another tissue which has the role of sticking the teeth to the jaw bone. 

Enamel is the hardest tissue in the human body though it is brittle. But the Dentine is less mineralized and relatively softer and less brittle, so needed for support. 

Wednesday, November 4, 2009

Lipoproteins


Firstly let's take a look at lipids. Lipids are a group of matter which are also found in our body. A more common name used for it is fat. Cholesterol and Triglyceride are two of them.

These lipids are absorbed into our body by eating food. And just like any other thing we dump in our mouth, these lipids join the flow of digestion and after the breakdown, enter the bloodstream. It is known that the blood stream is 90 percent water-based and in obeisance to the law of chemistry, lipids (fats) and water do not mix. So the cholesterol and triglyceride particles can't travel alone in the bloodstream.

So they are carried around in packages called lipoproteins. They are secreted by the liver and eventually return to the liver. Lipoproteins are divided into a couple of groups. The three main ones are:

1)      LDL (Low Density Lipoproteins)
2)      VLDL (Very Low Density Lipoproteins)
3)      HDL (High Density Lipoproteins) 

VLDLs carry cholesterol and triglyceride. On their way, they drop some of the triglyceride and become LDLs. So Low Density Lipoproteins carry only cholesterol. LDLs also displace some of their passengers (cholesterol) as they flow along in the bloodstream. That's why these two are called "bad cholesterol". So, they drop some of the passengers off on the way but they themselves and the rest of the passengers are taken back to the liver for metabolism.  

On the other hand, HDLs sweep off the cholesterols and triglycerides in the bloodstream. And as high levels of these lipids can cause many problems such as heart problems, HDLs are called "good cholesterol".

So the more HDL exists in our bloodstream, it is better for us but the more LDL rate means trouble, such as atherosclerosis, stroke, heart attack, ischemia, and much more.

There are two ways we can have healthier blood vessels and overall, a healthier heart. One is by eating food with less fat to decrease the amount of LDLs. And two, by eating food which help in increasing the population or effect of HDLs. For example: antioxidants (such as vitamins A, C and E; garlic; onion) and also Niacin (vitamin B3).