The condition of the teeth of each shakuhachi player is different and as a result, each person blows in a different way. According to the physical anthopologist Yamada Tadao, when one examines rigorously the teeth of human beings, one finds that they are not symetrical from left to right. So when the shakuhachi is played, depending upon the arrangement of his own teeth, the player holds the instrument to the left or right to a small degree. The shakuhachi player must search for the point that is best for the condition of his own teeth.
When the condition of the teeth deteriorates and they are replaced by dentures, very often it is impossible to produce the accustomed sound. Or in some cases, the sound becomes very weak. This is because the dentures interfere with the flow of air through the oral cavity and across the lips. Therefore, it is desirable to consult in advance with a friendly dentist and have a plaster cast of the healthy teeth prepared. Of course, the gums also change as one grows older, so it is difficult to effect a complete restoration, but undoubtedly the plaster cast will prove useful. If you do this before hand, then even if you must wear dentures, to some degree you can preserve your sound of the shakuhachi. (Kitahara)