Dental caries is one of the important national health problem in Japan, especially for school children since long time ago. Method of diagnosis of dental caries is prefered the palpation method with sharp needle tip for inspection method in early stage of the affection 1). According to the national nutrition survey 2) by the Welfare Ministry, the incidence of dental caries reaches already in early infancy such as 2 to4 years old to about 60 per cent for both sexes, increasing gradually with increasing age (Table 1). At the time of teeth exchange the percentage figure drops once a little to increase again thereaftr with growing age (Graph 1).
Among various kinds of malnutrition, most common vitamin deficiencies shall be reported here. (1) Vitamin B1. Typical beriberi cases have been disappearing since the discovery of thiamine, but mild form of beriberi patients are not yet decreased so apparently, due to the still prevailing thiamine shortage of the daily diet for Japanese people. The diagnosis of beriberi may be possible in recognizing such symptoms as loss of tendon reflex on knie and ankle joint, calf tenderness, hypesthesia on hand and leg, lowering of blood pressure and slight edema on lower leg. Besides these objective symptoms, several kinds of subjective complaints, such as loss of appetite, full and heavy sensation of stomach, constipation, palpitation, short breath, easy fatigability, disturbed sleep, dizziness and nervousness etc. may be considered as coincident symptoms. Through such diagnostic procedure, we can detect the mild form of beriberi still about 20 per cent of entire nation, and the result of national nutrition survey by Welfare Ministry give about 8 per cent of population as beriberi cases examined only through the loss of tendon reflex on knie joint. Dr. T. Sawada in Kyushu University found also about 20 per cent of population as mild form of B1-deficiency through his urine test for pyruvic acid (Tables I and II). Regarding the prevention of thiamine shortage, B1-enrichment of white rice will be explained briefly in this presentation. (2) Vitamin B2. Among various symptoms due to B2-deficiency, angular stomatitis (so-called perleche) is most common among Japanese people, which amount about 6 per cent in its frequency according to the national nutrition survey (Table III). By further detailed survey by the author in several different groups during several years, it was discovered far higher in its frequency, namely 20 to 30 per cent of population in both sexes.