The Korean people are not immune to caries but, compared with Western peoples such as American or British, have a noticeably low incidence. Perhaps 40 percent of the people are susceptible, but the number of carious teeth per susceptible person does not average more than two or three. Caries in anterior teeth is extremely rare. Carious spots may be due to food impactions at surfaces where enamel has been broken. Enamel fracture and abrasion are common, owing to presence of stone grit in the roughly prepared grain in the diet. Periodontoclasia, which is common, bears no relation to incidence of caries. Modern civilization, railroads, highways, automobiles— making imported products available to the country people—are bringing about changes in the diet of many persons. Those (individuals, families, groups who add sugar, candy, bread or pastry to the diet show marked increases in susceptibility to caries.
For many generations the Korean people (20 millions) have had typical and rather limited diet—quite different from that of the Japanese and Chinese—consisting, in the main, of much rice or millet with a pickle of uncooked cabbage, turnips, garlic, red pepper, prepared in salt-brine and allowed to ripen or ferment. Meat, fish, greens and fruits have been occasional or seasonal additions. Some sugar is eaten in honey and fruits, but commercial sugar as in candy or table sugar, and white bread and pastry, are entirely foreign to the typical Korean diet. As yet the only Korean people having access to American food are servants in American and British homes. This group shows the highest incidence of caries—the only Korean mouths in which caries is rampant. They live on the typical Korean diet, but daily taste Western food, the oral debris from the latter having deleterious dental effects.
Reference: J. Sev. Union Med. Col., 3, 1935.