Abstracts From Abroad

Effects of Civilized Foods on Native Races

                Important research has been carried out by Dr. Weston A. Price of Cleveland. Ohio, in the South Sea Islands, and an outline of his studies in these regions appears in The Dental Journal of Australia. Investigations were made on each of eight archipelagoes, as follows: Marquess Islands, Society Islands, Cook Islands, Tonga Islands, New Caledonia, Fiji Islands, Samoa Islands and the Hawaiian Islands. The primary purpose was to make a comparison of the health of these various primitive racial stocks when living in isolated districts and where they were in contact with modern civilization. Many groups were found who were still living almost entirely on their native foods, such as their ancestors had used for centuries. These natives had very much better physical development with a very high immunity to tooth decay as compared with those of the same racial stock who were living near the port of call of merchant or trading ships, and at such points as supplied imported foods, chiefly white flour and sugar. Many hundreds who were isolated from contact with the foods of modern civilization were examined, and not a single tooth was found that was seriously out of alignment in the dental arches. No irregular teeth were found, and no associated disturbances of facial development had occurred. But among those who during infancy and childhood had been under the influence of imported foods, these disturbances were very common and were in form and characteristics like the divergences from normal which are found in people of America or Europe, New Zealand or Australia, and all other modernized communities. Studies made in the South Sea Islands, when correlated with those made by Dr. Price among the Eskimos of Alaska, the Indians of Northern and Central Canada, the Gallics of the Outer Hebrides and the Swiss of the Alps, showed that all developed the same divergences from normal on adopting the foods of modern civilization, particularly white flour and sugar and sweetened goods of all kinds. Refined sugar provides no minerals or vitamins, and four-fifths of the minerals have usually been removed from wheat to make white flour. In the South Sea Islands groups living almost entirely on native foods there was usually an average of about one to six teeth per thousand of the teeth examined that had ever been attacked by tooth decay. In those groups, however, that were displacing part of their native foods with white flour and sugar products this figure often increased a hundredfold, averaging about three hundred teeth per thousand teeth examined. In the latter group, also, the death rate usually far exceeded the birth rate: the population rapidly decreasing owing to degenerative diseases such as affect the people of our modern civilizations. These diseases affect much less the people living on their native foods.

For the people of the South Sea Islands the major part of the intake of required minerals and activators as originally provided in sea animal life, and displacing these foods with imported white flour and sugar products, which are very much higher in calories or energy, and thereby easily satisfy hunger, but which are low in body-building and repairing materials. It is not without very great significance that most of the tubercular patients in many of the island groups are chiefly to be found around the ports, apparently not chiefly due to increased exposure to tubercular infections, but to lowered defense for resisting and combating the infection. It is also of great significance that tuberculosis is most active in the new generation that has been physically injured by the inadequate nutrition of their mothers and themselves. These are the individuals in all lands who are chiefly developing the degenerative diseases of the skeletal, nervous and circulatory systems. Two thousand negatives were made and very many samples of foods were chemically analyzed. Hundreds of individuals were personally examined and valuable data obtained.

—From Oral Topics.

No Bone Necrosis in Pyorrhea

Dr. David Ellis, of Melbourne, publishes in The Australian Journal of Dentistry certain conclusions arrived at after an investigation of various conditions associated with pyorrhea. These were incorporated into a thesis successfully submitted to the University of Melbourne after a long period devoted to research. Dr. Ellis’ studies have convinced him that:—

(1)    Pyorrhea is not a disease entity, but is a natural end result of a simple local inflammatory condition of the gingiva. While admitting that a constitutional factor may leave a tissue concerned “below par,” the results of this study do not indicate that such is a necessary corollary.

(2)    Pocket formation is established by chronic epithelial proliferation with degeneration of the superficial layers of epithelial cells at the gum margins and a splitting of the epithelium at the base of the ulcer bordering the cementum.

(3)    The epithelial downgrowths which take place along the cementum are definitely bound by that tissue to the tooth. Cementum acts as a specialized connective tissue.

(4)    Epithelial remnants on the erupted cemental walls of the teeth are the nuclei upon which tartar deposits are formed.

(5)    There is no necrosis of bone. Sequestra are not formed. Resorption of bone is progressive, beginning at the alveolar edge and not in the body of the bone. Bone undergoes a slow progressive change, first to osteoid tissue and then to fibrous tissue.

(6)    A simple hyperaemia with metabolites is not sufficient to cause marked change in the alveolar bone.

(7)    When gingivitis is established, mouth bacteria enter the tissues and act as sustaining causes. This is largely dependent upon the predisposing conditions prevailing.

(8)    In advanced stages of the disease there is mass microbic infection of types of organisms not yet identified, and a mild osteitis is produced in the alveolar bone.

 

—Oral Topics (London).

 

Does Pyorrhea Loosen the Upper or Lower Teeth First?

 

Dr. R. Morse Withycombe, of Sydney, claims that his experience indicates that in pyorrhea the upper anterior teeth are lost before the lower anteriors. In an article contributed to The Dental Journal of Australia he sets forth the reasons for this conclusion based upon observations extending over very many years’ practice as a periodontist. During the Middle Ages the anterior teeth met edge to edge; to-day the upper anterior teeth overlap. The edge to edge bite gave the individual no trouble to were a facetted track, well clearing the canines, which prevented traumatic occlusion occurring, and gave an excellent function. To-day it is rare indeed to find a person of 12 years of age with the teeth well cleared for action. He mentions two out of several classes of normal working bite as existent at the present time.

Class 1.—In centric occlusion, and all eccentric occlusal positions, the occluding surfaces of the teeth are worn and in the same plane. This function is characteristic of normal man, but in the younger generation is almost extinct. At puberty probably not more than one per cent can now be found who function normally with the teeth. In this class freedom will be observed for the mandible to move under masticating stress in all directions without impediment, and well-worn cusps are always in evidence. The mandibular teeth move along a definite plane of occlusion, exerting up to 250 pounds pressure. Food is thoroughly triturated and insalivated, and the walls of vegetable cells being crushed the ingestion of food is normal for digestion. Food does not jam between the teethbecause there is no jamming or pounding in normal mastication. There is, moreover, little danger of traumatic occlusion, because the function works smoothly and surely, bringing health to the periodontal tissues and indirectly to the constitution.

Class 2.—The mandibular teeth are restricted to an antero-posterior excursion, a predominating function which is typical of pyorrheics. The mandible moves forward and backward, slightly varied by a very modified right and left lateral excursion. The movement has its transverse occlusal convexity upwards, and the plane of abrasion wears the outer cusps of the lower teeth first, as is also observed in apes. The determining influence of this function as a causative factor in pyorrhea is the force with which the mandible thrusts the lower central teeth up and forward against the palatal surfaces of the upper anteriors, and, notwithstanding the reinforcement of bone supporting these teeth, they sooner or later break down under ceaseless traumatism.

 

It proves to be, according to Dr. Withycombe, purely a matter of mechanics. A force let loose in the month of between 100 and 200 pounds must do serious damage if not properly directed. Under the continual thrust forward and upward the upper teeth lose their grip.

 

—The Dental Magazine and Oral Topics.