Department of Orthodontic Abstracts and Reviews

DKS. EGON Neusra~~ .WD JOSEPH D. EBP, NEW YORK CITV

All communications concerning further information about abstracted material and the accept- ance of articles or books for consideration in this department should be addressed to Dr. Egon

Neustadt, 133 East Fifty-Eighth Street, New York City.

Obserwtions on Teeth of Chinese. By S. A. Montelins, d. Dent. Res. December, 1933.

A total of 4,474 (Chinese were examined, males and females, a.ncl belong- ing to various social strata.

A very high percentage (79 per cent.) presented t,he so-called “sl~~~el- shaped” incisors, which are characterized by highly developed mesial rind distal marginal ridges. (Incisors of a similar shape have been described in American Indians.) The second mandibular molar, which in the white race carries four cusps, has frequently (56 per cent) five cusps among the Chinese. However. variations in number and size of cusps are not infrequent, and the theory ma)- be advanced that the fift~h cusp is gradually becoming scarce and may corn- pletely disappear in t,he future.

An overbite of the maxillary incisors over the mandibular incisors pre- dominates, varying from mild to excessive degrees. It, is in many cases ac- companied by an over,jet of the maxillary anterior t,eet 11. The high ErequeneJ- of overbite is evidenced by the fact t,hat 89 per cent presented it. Hntl-to-em1 bite occurred in 6 per oent. Only 20 individuals had mandibular incisors protruding over the maxillary incisors. (It is not stakd whether a trm mesioclusion condition accompanied these cases.) Altogether, irregularities were found in 33 per cent of cases.

Occlusal abmsiou in the molar region was far greater than t Imt, ilsuall> found among other races. Of 4,466 individuals, 977 sho~rd occlusal abrasiou (21 per cent): although most persons examined were only from tell to twenty- nine years old.

Mottled wn,d chalky enamel was oft,en seen, and always endemic in certain regions. Calcareozcs deposits on the teeth were common (92 per cent,). Gingi-

v&is and pyorrhea occurred with great frequency (81 per cent). The number of cariozcs teeth was oaly 8 per cent of the total examined. Contrary to con- ditions in the white race, the maxillary molars are more susceptible to decay than are the mandibular molars.

The soldier group showed higher percentages of gingivitis and pyorrhea. The student group showed higher percentage of malocclusions and caries. This may be due t,o the increased modernization of living conditions in t,hc

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latter group. The association of caries with rnaJocclusions should be noted. Fzcrth.ermore, caries appemed with 10 per cent greater fwquency in individuals having irregular teeth,

-43. N.

Diet and Bone Development. By Dr. William J. Corcoran, J. A. 1~. A., April, 1934.

The discovery of the vitamins has made the orthodontist food conscious. In many instances, where treatment results are unsatisfactory, he turns his attention away from appliances to a more intimate study of the Gssues wit>11 which he has to deal. Nutritional agents play an ever increasing r81e in his orthodontic instrumentarium, but the import,ance of diet must not be allowed t,o overshadow other significant requirements of health. Dr. Corcoran makes a cIear and systematic survey of the food problem in bone development, but not without pointing to those ot,her fact,ors which must, be considered in bone growth, besides diet.

Is everyone living in a state of calcium deficiency? Is the so-called bal- anced diet adequate for normal bone growth? Is there anot,her factor drter- mining the state of bone development besides the dietary?

In an examination of 5,000 children it was found that a large number showed bone hypoplasia despite the fact that their diets were well balanced. On the other hand, a large number of children, whose dietary was definitely deficient, had no signs of bone hypoplasia. The conclusion was finally reached that in the majority of ca,ses diet was a predisposing rather than an active factor in faulty bone development.

The problem is further complicated by the fact that, due to recent dis- coveries in food metabolisms, manufacturers have placed various new food products on the market. There are more kinds of foods, tastes, and mental appetites now than there ever were before.

BASIC ELEMENTS OF FOOD

However, if we apply a critical analysis to the foods which constitute our meals, we find that they consist of certain basic elements, namely: milk, eggs, vegetables, grains, fish, meat,, and fruit. The Neanderthal man depended on these, and our own fanciful dishes consist of them. We are still eating nature’s primary foods, even if they are presented to us under different names.

Junket is milk. Custard is eggs. Cookies are grains. Prunes are fruit.

BALANCED DIET

Balanced diet is a combination of foods in the same chemical composition as they are found in the human body. These chemical materials consist mainly of: carbohydrate, protein, fat, salt, water, and vitamins.

Protein should supply 10 to 15 per cent of the total food.