It is often overlooked that the path of Yoga does not start with the practice of asanas (postures), pranayam (breathing excercises), tantric ritual, etc... Within the eight-folded path of Astanga Yoga, Yama (Controll) and Niyama (Rules of Conduct) come first. They represent a set of practical, moral and spiritual do's and dont's that prepare the yoga practicioner for succesfully applying the actual yoga techniques.

Yama and Niyama must be mastered before perfect balance and a conscious connection to the divine bliss can be attained through asana, pranayam, pratyahara, dharana, etc... Basic body purity is one of the disciplines that belongs to Yama (Controll), which also includes nonviolence, truth, honesty, sexual continence, forbearance, fortitude, kindness, straightforwardness and moderation in diet.

When the teeth are not properly kept clean, decaying food particles will create a bad taste in the mouth, thus continuously sending distress signals to body and mind. As for all senses, the disturbed sensory input to the tastebuds will trigger electrochemical and biochemical signals that are send to the brain and to the entire body. This continous murmur of signals will affect our sense of calmness and well-being, reduce our ability to concentrate or relax, etc... This effect can be compared to a continuous presence of pain that often makes people become edgy and distracted. Obviously a bad taste in the mouth will not have an effect as strong.

Much the same can be said for body purity in general. Irregular bathing will mostly cause distress signals to be send through the sense of smell. Even without us really being aware of it, our ability to find peace will be reduced. Only really strong smells reach our awareness, whole our nose registers an infinite array of airborn molecules. Similarly, infrequent bowel movements will increase the amount of disturbing toxins in the blood and disturb body chemistry and prana, leading to increased nervousness. Again the same goes for our living environment. When overall sensory input cannot be avoided, it pays to keep it on a sattvic (light, calm) level, rather than being overly rajasic (stimulating) or tamasic (numbing, distressing). More about these doshas here. This is one of the important levels where yoga and spirituality meet art, home decoration, cultural rules, etc... In most religions, body purity is essential before partaking in any ritual.

Not caring for body purity or a pleasant living environment may be a path in itself. Training to ignore bad smalls, noises, sights, etc.. improves the mastery of the senses. But then it represents a concious effort that can also be combined with severe spiritual practices that allows the purity from within to counter the impurity on the outside. For example, the inner reciting of a mantra may help us to forget about the disturbing sounds of traffic. It is also generally important not to become too dependend on a nice environment, clean clothes and a daily bath to feel OK, because they might not always be available. A subtle balance must be kept between proper and conscious maintenance of daily purity habits and the flexibility to adapt them to circumstances. Above all, the inner purity must be kept intact.

For a highly trained yogi that has mastered a full withdrawal of the senses (pratyahara), dirty teeth may not have any impact at all. In fact, some advanced yogic practices may exist that completely stop the process of decay of food particles in the mouth. But for less advanced yoga practicioners dirthy teeth are not exactly a good start, disregarding even the longer-term risk of toothaches.

According to the "Dhanwantari" book on ayurveda in daily life (by Harish Johari), various teeth cleaning methods will do, from brushing with a fresh twig or toothbrush to using toothpaste, toothpowder, etc... The quality of any product taken into the mount will obviously not be without effect either, through taste and through eventual ingestion. Mordern devices using pressurized water can be used, though the vibrations of the electric pumps can be disturbing in the early morning hours. Whatever you do, just rinse the eyes along with the mouth.

Text written by Peter Marchand. Many aspects of body purity and Yama and Niyama in general are described in full detail in the book "Dhanwantari" by Harish Johari.