Sunday, May 23, 2010

Missing Teeth Linked to Heart Disease

Teeth linked to heart disease


AFP,The West Australian April 13, 2010, 6:45 am

People with dented smiles run a far greater risk of dying of heart disease than those who still have all their pearly whites, a Swedish researcher says.
Cardiovascular disease and, in particular, coronary heart disease was closely related to the number of teeth a person had, researcher Anders Holmlund said.

"A person with fewer than 10 of their own teeth has a seven times higher risk for death by coronary heart disease than a person of the same age and of the same sex with more than 25 teeth left," Professor Holmlund said.

Although many studies published in the past 15 years had shown a link between oral health and cardiovascular disease, Professor Holmlund's study showed a direct relationship between cardiovascular disease and the number of teeth in a person's mouth.

The study, conducted with colleagues Gunnar Holm and Lars Lind, surveyed 7674 women and men, most suffering from periodontal disease, for an average of 12 years, and examined the cause of death of the 629 people who died during the period. For 299 of the subjects, the cause of death was cardiovascular disease.

Professor Holmlund said the theory connecting teeth numbers and heart disease maintained that infections in the mouth and around the teeth could spill over to the systemic circulation system and cause a low-graded chronic inflammation, which was known to be a risk factor for heart attacks and other cardiovascular episodes.

The number of natural teeth a person had left "could reflect how much chronic inflammation one has been exposed to in a lifetime", he said.
The study had been limited by the fact that it had not been possible to adjust the results for socio-economic factors and to fully adjust them according to other cardiovascular risk factors.

Heart disease is the number one killer worldwide, claiming more than 17 million lives every year, according to the World Health Organization.

Brother CK,

I am a bit worried because I have lost a few teeth and undergone double cabg. Maybe our good friend and Dr JB Lim can give further insight into this article:

Thanks
Perry Tan


Dr JB Lim Comments:

I have never heard of this before. Show me the article and the reference or the journal where the study was published. I want to see the design of the study, the data and the statistical analysis of the data, and the conclusion he derived. I am extremely fussy about this as a medical researcher and a trained medical statistician.

The number of teeth left in a person is also related to his age – the older he is, the lesser teeth he would have left. This is natural. Wouldn’t the chances of death due to old age naturally becomes higher and higher the older the person is whatever the cause? The causes could be anything from accidents, cancers, infections, and degenerative diseases, and not necessary heart disease alone. Ultimately everybody dies of old age.

The only thing I can think to relate oral infection (Strep throat) to heart disease is Group A streptococcal infection (GAS), specifically the bacterium Streptococcus pyogenes that may give rise to acute rheumatic fever and rheumatic heart disease, and Streptococcal toxic shock syndrome. This is well-known and is not new to us as it is described in any standard text-book of medicine. This has nothing to do with the DMF (decayed, missing and filled) teeth in the mouth.

I think this professor or doctor here is talking nonsense. Some of them do. I have come across lots of them as my colleagues in my 25 years of professional career as a researcher.

Dr JB Lim BSc PG Dip Nutri MSc MD PhD FRSPH FRSM

Special Medical and Science Adviser
Head of the Technical Advisory Board
The Dynapharm Int’l Pharmaceutical Group

Dear Perry,

Thanks to Dr Lim, I am happy that you are okay after all do take care of your food and regular exercise.

Regards,
C K

Dear Dr. Lim Ju Boo

It is possible. Our health related to food and teeth or more the mouth section. Our mouth tends to have ulcer. Worse would be the diabetic patients

Dr. Chan Boon Lye

Dear Dr Chan,

Thank you for your comment.

Yes, of course. Our choice of food and our ability to chew and eat them is definitely determined by state of our teeth. In turn our overall health depends on the nourishment we get and our ability to choose and masticate the food. Hence nutrition is the direct function of our dental health. There is no doubt about this. This is a very old knowledge which I learnt even as an undergraduate student. I do not doubt this. But this was not what I was able to relate.

Missing teeth and heart disease?

What I was unable to find was a relationship was ‘missing tooth and heart disease specifically.’ This was news to me. I have already commented on the very old knowledge we already know how a sore Strep throat caused by a group A streptococcal infection in children may lead to rheumatic fever and rheumatic heart disease later in life in which the heart valves especially the mitral valve are incompetent or totally damaged. This is also not new to us.

Ever since I made that remarks people has been calling me if I could think of any other possibility where the heart can be affected by missing teeth since Professor Holmlund's study showed ‘a direct relationship between cardiovascular disease and the number of teeth in a person's mouth’.

Which specific heart disease?

Quite honestly I just do not know. First of all, I do not know what Prof Holmlund meant by cardiovascular disease (CVD). There are so many types of heart diseases involving the heart muscles – cardiomyopathies from congenital heart disease, nutritional diseases affecting the heart, ischemic and non-ischaemic cardiomyopathy, hypertensive cardiomyopathy, valvular cardiomyopathy, inflammatory cardiomyopathy, cardiomyopathy secondary to a systemic metabolic disease, alcoholic cardiomyopathy, diabetic cardiomyopathy, to restrictive cardiomyopathy. Which heart muscle disease did Professor meant? I presume he meant CHD or CAD (coronary heart / coronary arterial disease)?

What has missing teeth got to do with CAD?

Really I do not have the faintest idea how CAD caused by a blockage or a stenosis of the coronary arteries has anything to do with missing teeth?

Heart block?

Alternatively the only other thing I can think of is a ‘heart block’ which is an entirely different pathology of the heart from CAD. As far as I know, this also has no connection with the number of teeth in the mouth? Heart block here means (as all cardiologists know), is an anomaly of the conduction system within the heart. It is a medical condition in which the electrical impulse generated in the SA node in the atrium does not propagate to the ventricles. There are many types and degrees of heart block - first-degree AV block, second-degree AV block, bundle branch block, or bifascicular block. Type I second-degree heart block, or Mobitz Type I, or Wenckebach's AV block. A third-degree AV block is known as a complete heart block.

Causes:

Many conditions can cause third-degree heart block, but the most common cause is coronary ischemia or an acute myocardial infarction. This is the only condition where the two are related as far as my limited knowledge in cardiology allows me comment.

Progressive degeneration of the electrical conduction system of the heart can lead to third-degree heart block. Of course there are many other causes of heart block too, and not just a squeal of a heart attack. But all their aetiologies (causes) are intra-cardiac (within the heart muscles), and are not extra-cardiac in nature.

The vagus nerve to the heart:

The only nerve outside that affects the heart is the vagus nerve – the 10th and the longest nerve. The vagus nerve is actually two nerves, both of which run from the brain stem and branch out separately, down the body, across the abdomen and to the main organs such as the heart and stomach. This is the only nerve that directly controls a number of bodily functions, such as breathing, maintaining digestive function, keeping the brain up to date with what we have eaten or digested and cardiac rhythm.

Physiology of vagus innervations:

Parasympathetic innervation of the heart is mediated by the vagus nerve. Specifically, the vagus nerve acts to lower the heart rate. The right vagus innervates the sinoatrial node. Parasympathetic hyperstimulation predisposes those affected to bradyarrhythmias. The left vagus when hyperstimulated predisposes the heart to atrioventricular (AV) blocks. All these we know. The physiology of this innervation is nothing new to us.

Missing link:

But there is missing link here. The vagus nerve is not connected to the teeth, but it supplies to a few muscles in the mouth for mastication and for speech and keeping the larynx open for breathing. But it does not innervate the teeth.

The nerve to the teeth:

It is the trigeminal nerve (the fifth cranial nerve, also called the fifth nerve, or simply CNV) that is responsible supplying nerve to the teeth and also for sensation in the face. The fifth nerve is primarily a sensory nerve, but it also has certain motor functions (biting, chewing, and swallowing) like the vagus nerve to a few other muscles of the mouth.

One is the 5th cranial nerve (trigeminal nerve), the largest cranial nerve and is the great sensory nerve of the head and face, and the motor nerve of the muscles of mastication, and the other is the 10th cranial nerve (vagus nerve). But they are anatomically separate and have little to do with each other except they are all connected to the brain.

My simple ignorance:

So with this very simple anatomical explanation of mine you can see nether the trigeminal nerve has anything to do with the heart, nor the vagus which has something to do with the heart, has anything to do with the teeth.

Each went separate ways. In short I do not know the answer. Only Professor Holmlund who did all that funny finding has the answer. Maybe he can explain. Maybe not, but I doubt he can himself. You ask him, and don’t trouble me. I am not an expert on oral pathology and cardiology.

Regards
Lim Ju Boo

Dear Dr. Lim Ju boo,

Yes, I could not disagree with you.

A good analysis,

Boon Lye, Dr. Chan

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