By Dr Bertrand R Stuart, DDS
RECENT experiments have shown that by routing signals from helmet-mounted cameras, sonar, and other equipment through the tongue to the brain, scientists can give elite soldiers superhuman senses similar to that in owls, snakes and fish. Researchers at the Florida Institute for Human and Machine Cognition envision their work giving Army Rangers 360-degree unobstructed vision at night, and allowing Navy SEALs to sense sonar in their heads while maintaining normal vision underwater – in essence, turning sci-fi into reality. All this centrally involves the tongue, which we all take for granted although it’s the organ supplied by more cranial nerves than the brain and heart combined.

But even as all this is going on, tongue diagnosis in Traditional Chinese Medicine (TCM) remains an indispensable guide in differentiating syndromes and diseases as, according to the art, all the meridians of the viscera (internal organs) connect directly or indirectly with the tongue. For example, the colour almost always reflects the true condition of the patient.

The tongue’s body and coating are unaffected by short-term events or recent changes. Its appearance monitors the improvement or decline of the patient’s condition.

The different areas of the tongue correspond to different organs in the body. Advantages of using the tongue in diagnosis include the fact that it is objective compared with the many variations of the pulse and the pulse taker. Also, it’s easy to interpret and will help you understand your own health. However, a limitation is the lack of precision in diagnosing the source of the problem, which would take more patient information and laboratory tests.

The normal colour is pale red. When it’s pale, that indicates blood deficiency such as anaemia. Purplish/blue indicates a poor circulation of blood often seen in heart disease. Shape (including consistency), texture, and motility commonly reflect a deficiency of vitamins or malnutrition. The tongue could be thin, swollen, stiff, flaccid, long, short, cracked, quivering and deviated. Its coating is a physiological by-product of the stomach’s digestion of food and fluids. Sometimes, this could be confused with poor oral hygiene.

In TCM, digestive function depends on spleen chemistry and transportation of food, and the stomach’s processing of it. In the process, residue reaches the tongue. The moisture, wet or dry, on the tongue shows the state of the body fluids. The tongue’s coating colour shows the presence, absence and strength of a disease.

A ‘blue’ tongue and face is normal for a pregnant woman, showing there is activity in the womb. For them, a normal tongue has a medium white coat and is very red.

The shape is not as important as the coating. The centre of the tongue indicates the most about the digestive history of the patient. To understand the state of the heart, look way back at the root of the tongue for redness. If the tongue is very pale, it indicates a very high fever is imminent and the coating would be white. If the tongue is a reddish purple, especially around the tip, the person may or may not have a heart problem. But that needs to be investigated.

Modern medicine notes that some tongue disorders include:

* Loss of taste

* Sore tongue

* Black hairy tongue

* Glossodynia

* Benign migratory glossitis

* Tongue-tie.

Loss of taste
Taste is a chemical sense that is activated during eating and drinking. Reasons for a loss of taste include:

* A person may lose their sense of taste if the facial nerve is damaged in some way. For example, Bell’s palsy may stop the facial nerve working properly and prevent or reduce chewing function (and, therefore, alter taste). It is uncommon for every taste nerve (bitter, salty, sweet and sour) to be affected.

* The auto-immune disorder known as Sjogren’s syndrome causes reduced saliva production, which in turn reduces the sense of taste. This is because the taste buds can only detect flavour when food is properly mixed with saliva.

* Glossodynia, a condition characterised by a burning sensation on the tongue, is also linked to loss of taste in some cases.

* Some medications can result in an unpleasant metallic taste in the mouth, such as tetracycline (an antibiotic), lithium carbonate (an antipsychotic) and captopril (an antihypertensive).

Sore tongue
A sore tongue is usually caused by some form of trauma, such as biting your tongue, or eating piping-hot or highly acidic food or drink. Other causes of a sore tongue include:

* If your top and bottom teeth don’t fit neatly together, tongue trauma is more likely.

* Some people may experience a sore tongue from grinding their teeth (bruxism).

* Disorders such as diabetes, anaemia, some types of vitamin deficiency and certain skin diseases can include a sore tongue among the range of symptoms.

* A sore tongue can be caused by disorders including black hairy tongue.

Black hairy tongue
While the term ‘black hairy tongue’ suggests the tongue surface looks black, it may also be dark yellow, brown, green or white. The tongue papillae are constantly renewing themselves and, usually, the old cells are shed as the new cells emerge. Black hairy tongue, a comparatively rare condition, is caused by the failure of the old cells to shed.

The overgrowth of papillae traps food and bacteria, which create the characteristic dark ‘coat’ on the tongue’s surface, while the tongue looks furred because of the layering of unshed papillae. The cause isn’t known, but risk factors include:

* Poor oral hygiene

* Cigarette smoking

* Particular antibiotics

* Chemotherapy and radiation treatment for cancers of the head and neck

* Poorly managed diabetes.

Glossodynia
The main symptom of glossodynia is a burning sensation on the tongue surface. The various causes of glossodynia can include:

* Local infections, such as oral thrush (candidiasis)

* Damage to the lingual nerve

* Damage to nerves of the mouth during dental extractions

* Cigarette smoking

* Vitamin deficiencies

* Particular medications, such as diuretics and some blood pressure drugs.

Benign migratory glossitis
This condition is characterised by irregular and inflamed patches on the tongue surface that often have white borders. The tongue may be generally swollen, red and sore. Another name for this condition is geographic tongue. The cause of benign migratory glossitis is unknown, but risk factors are thought to include:

* Mineral or vitamin deficiencies

* Local irritants, such as strong mouthwashes, cigarettes or alcohol

* Certain forms of anaemia

* Infection

* Certain medications

* Stress.

Tongue-tie
The medical name for tongue-tie is ankyloglossia. Frenula are little strings of tissue found underneath the tongue, inside the cheeks near the back molars, and under the top lip. The frenum (or frenulum) under the tongue is called the lingual frenum. Tongue-tie is a condition characterised by a short frenum that stops the tongue from poking out past the lips. Other symptoms can include:

* Tongue tip can’t touch the roof of the mouth

* Tongue can’t be moved sideways

* Tongue tip may look flat or square instead of pointy when the tongue is extended

* Tongue tip may be notched or heart-shaped

* The front teeth in the lower jaw are gapped

* History of feeding or sucking problems.

Diagnosis methods
Depending on the disorder under investigation, diagnosis methods can include:

Physical examination
* Medical history

* Salivary gland tests

* Biopsy.

Treatment options
Depending on the disorder and cause, treatment options can include:

* Loss of taste - treatment for the underlying disorder, such as an artificial saliva spray or gel for Sjogren’s syndrome.

* Sore tongue - avoid hot, spicy or acidic food and drinks until the injury heals; wear a mouth guard at night to prevent tongue trauma from bruxing (teeth grinding); dermatological treatment for the skin disorder; treatment for the underlying disorder such as iron supplements for iron-deficiency anaemia; better yet, a balanced diet will certainly solve the problem since a sore, swollen and red tongue usually indicates severe vitamin and mineral deficiency.