There is no consistent relationship between tooth structure, oral hygiene, and caries. No direct correlation is evident between the chemical balance of the oral environment and caries. There is a fairly definite relation between a diet adequate in calcium, phosphorus, and vitamins C and D, and freedom from caries. Relative freedom from caries results from the provision of an adequate constitutional development—diet—before birth and during the formative years of infancy and childhood. At present the constituents of this ” adequate ” diet are not clearly defined.
In a study of the racial incidence, prehistoric and modern, of dental disease in a large series of crania, the author found that the correlation of susceptibility to caries with facial and body types is not a direct cause-and-effect relationship. Constriction of mid-face, linearity of body, and caries of teeth, are phases of a single problem, the relationship being symptomatic, not causative. Frequency of caries increased with the progress of civilization, but this disease is not a product of civilization ; prehistoric and primitive groups of people have had, and have, higher rates of caries than is generally believed. There is no evidence of a true racial immunity or susceptibility to caries. All such alleged instances are trace‑able to racial diet rather than peculiar dental structure, oral environment, serological type, or other presumably related factors. Similarly, it has not been proved that disharmonic dento-facial relations, predisposing to caries, result either from race-mixture or the crossing of big-jawed and small-jawed individuals of the same race.
Reference: Z. Rassenkunde, 7, 41, 1938.