224 Reviews and uhstructs Am. .I. Orthod. February 198 1

Orthodontic Movement of Teeth With the Use of Magnetic Forces

Tom L. Darbonne Columbia Universit;v, New York, N. Y., 1979

Intraoral magnets were used for retraction of teeth. Previous investigations on this subject were performed on laboratory animals only. In this study four patients were selected to follow the work done by Blechman and Smiley, as reported in the AMERICAN JOURNAL OF ORTHODONTICS in October, 1978. This study was designed to determine the usefulness and effectiveness of small cobalt-samarium magnets for the retraction of teeth. The final result does not depend on the cooperation of the patient in wearing elastics. Magnets will allow the orthodontist to (1) manage this phase of treatment, (2) use a more continuous lighter force and possibly less time than is needed with elastics, and (3) use a more horizontal force by alignment of the magnets, thus reducing the downward tipping of the occlusal plane caused by elastics.

A Cephalometric Comparison of Deep Bites With Normal Bites

Alice Schwartz Chabora Columbia Ilniversity, New York. N. Y., 1979

An attempt was made to compare cephalograms of normal Class I control patients with deep-bite Class II experimental patients with respect to several cranial landmarks. Fifty- eight control cephalograms from the Whitman sample, collected at Columbia University School of Dental and Oral Surgery, were compared with 63 deep-bite cephalograms drawn from orthodontic patients at Columbia. A tentative conclusion reached from this study was that the dysplasia in deep-bite patients stems from the PUFH/LPFH ratio being dissimilar to the control sample’s ratio. Unlike the open-bite studies of Dr. Nahoum, the AFH of deep-bite patients appears within normal limits when compared to the control sample. Further study is needed to see if this posterior face height discrepancy can aid not only in explaining the etiology of deep bites, but in predicting success in their treatment. The fact that a skeletal dysplasia is noted suggests that deep-bite is not solely attributable to a dental supra- or infraclusion.