"Doctors must begin to recognize racial differences when planning corrective dental therapy," claims Dr. Peter T. Kai-jen Yen, assistant clinical professor of Orthodontics at the Harvard School of Dental Medicine.

"Orthodontists have to realize that the facial proportions of different races vary," Yen said yesterday. "What would be the proper treatment for a Caucasian may be completely wrong for a person of another race," he added.

Cited Evidence

Yen cited evidence to support his claim in a paper presented to the annual meeting of the International Association for Dental Research last Monday in New York.

"I have always felt that race must be taken into account in orthodontic treatment but my opinion was based only on personal clinical experience. Then, while spending two years in Taiwan, I saw the opportunity to do research that might lend some credence to my belief," Yen said.

Yen compared the facial proportions of 50 11-year-old Chinese boys with balanced faces and perfect bites to those of 50 American white boys with corresponding features.

Yen used x-rays to compare the upperfaces, the noses, the teeth, and the chins of the two groups of boys.

"The results were amazing." Yen said. "The Chinese upper face is shorter and has a flat contour, the nose is not as long and is more vertically inclined that that of the white, his teeth naturally protrude more, and the chin is naturally more backward in the face and is less distinctive." he added.

"The differences between the profiles are dramatic," Yen said. "It is easy for even a layman to see that a different treatment would be called for in order to maintain the proper facial proportions of each race," he added.

"It is important, now, that someone undertake a study to see if similar differences in treatment may be called for in regard to the American Negro." he added.