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AAO Endowment Fund
LETTERS TO THE EDITOR AAO Endowment Fund To the Editor: It has come to my attention that the AAOF endowment fund is falling short of its goal. A specialty cannot support its high principles of knowledge and service on the advertisement of new products alone, and must strive to enlighten itself through academics and basic research. The biology of the system on which we work and the understanding of the behavior of the hard and soft tissues is paramount to progress. Alas, more money has been spent on the production and promotion of the lingual appliances and ceramic brackets than has been spent on academics and research. The foundation of the orthodontic progression must be nourished from within by sponsoring scholarship, academic leaders, and basic research. The AAOF has pledged to do this. The purpose of the Foundation is to assure that the wellspring of our academic resources will continue into the future. I support the work and purpose of the AAOF wholeheartedly. llarry L. Doughertv Chaionan of Advanced Orthodontics USC School of Dentistr3' University Park MC 0641 Los Angeles, CA 90089-0641
Comments on nonextraction a zd extraction article To the Editor: I would like to congratulate the authors, Drs. Paquette, Beattie, and Johnston, for a most interesting and valuable contribution to a complex and frequently controversial subject in their article, "A Long-term Comparison of Nonextraction and Premolar Extraction Edgewise Therapy in "Borderline" Class II Patients," (AMJ ORTHOO DENTOFAC ORTHOP 1992;102:1-14), and also add a couple of comments. Observing some significant differences at the end of treatment between the extraction and the nonextraction groups "notably, the protrusion of the dentition and convexity of the profile"--the authors found that these differences were also present "a decade or so later." However, according to Table II, the differences of the distance, Lower Lip to E-Plane, became somewhat reduced between end of treatment and recall and changed from statistically significant to not significant mean values. This change in significance may, of course, be dueto increasing variability and, if so, that leads to my next comment. 22A
There is this saying that the mean is a lonely place to be, and a description of the variability of the data, preferably graphically, would, in our view, have been of great interest. The considerable variability that we frequently observe in our field can sometimes make findings more nebulous but are nevertheless part of the game. Further, since profile assessments are essential in the study, I think that additional tracings superimposed on the nose and chin would have given a better impression of differences in lip profile as compared with Figs. 4 and 5. On the basis of these viewpoints and knowing the material at the authors' disposal that could generate more valuable information, I should like to encourage the authors to consider a second publication. Please, do not let these remarks leave a negative impression. The article is highly appreciated and might become a classic one in the orthodontic literature. Rolf Berg, Prof. Dr. Odont. Chairman, Department of Orthodontics University of the Saarhmd 6650 tlomburg, Germany
Reply It is a pleasant experience to be asked to comment on a letter that, in effect, praises with faint damns. Dr. Berg is quite correct in the observation that, in terms of the two soft tissue measures, the treatments were not significantly different at recall. Our statement about the convexity of the profile was based on the mean tracings (Figs. 4 and 5) and on the finding that there was a significantly different net change in both the lower-lip-to-Eplane distance and the Z-angle. We should, however, have referred the reader to Table IV (rather than just to Figs. 4 and 5 and Tables II and Ill) and, in the process, we apparently should have been a bit more precise in our wording. Dr. Berg's suggestion that we might have superimposed the mean tracings of Figs. 4 and 5 on the nose and chin is of course a possibility. In the present instance, however, the chins and noses of the faces in Figs. 4 and 5 are almost superimposed as things stand. If a more exact nose/chin superimposition is required, a few minutes with some tracing paper is all that would be required of the interested reader. Finally, Dr. Berg is correct in noting that "the mean is a lonely place." It is, however, less "lonely" than any other place in a normal distribution. In any event, we would argue that, although a graphic depiction of the distribution of our data might well be of interest to some readers, our article was so long and contained so many measurements that histograms would be out of the question. Dr. Berg's basic point, however, is well taken. We would be happy, therefore, to send tables of sample standard deviations or even the raw data to readers interested in examining in greater detail the treatment variation seen here. Lyle Johnston, Jr. The University of Michigan Aml Arbor, Mi 48109-1078
Comments on nonextraction a zd extraction article To the Editor: I would like to congratulate the authors, Drs. Paquette, Beattie, and Johnston, for a most interesting and valuable contribution to a complex and frequently controversial subject in their article, "A Long-term Comparison of Nonextraction and Premolar Extraction Edgewise Therapy in "Borderline" Class II Patients," (AMJ ORTHOO DENTOFAC ORTHOP 1992;102:1-14), and also add a couple of comments. Observing some significant differences at the end of treatment between the extraction and the nonextraction groups "notably, the protrusion of the dentition and convexity of the profile"--the authors found that these differences were also present "a decade or so later." However, according to Table II, the differences of the distance, Lower Lip to E-Plane, became somewhat reduced between end of treatment and recall and changed from statistically significant to not significant mean values. This change in significance may, of course, be dueto increasing variability and, if so, that leads to my next comment. 22A
There is this saying that the mean is a lonely place to be, and a description of the variability of the data, preferably graphically, would, in our view, have been of great interest. The considerable variability that we frequently observe in our field can sometimes make findings more nebulous but are nevertheless part of the game. Further, since profile assessments are essential in the study, I think that additional tracings superimposed on the nose and chin would have given a better impression of differences in lip profile as compared with Figs. 4 and 5. On the basis of these viewpoints and knowing the material at the authors' disposal that could generate more valuable information, I should like to encourage the authors to consider a second publication. Please, do not let these remarks leave a negative impression. The article is highly appreciated and might become a classic one in the orthodontic literature. Rolf Berg, Prof. Dr. Odont. Chairman, Department of Orthodontics University of the Saarhmd 6650 tlomburg, Germany
Reply It is a pleasant experience to be asked to comment on a letter that, in effect, praises with faint damns. Dr. Berg is quite correct in the observation that, in terms of the two soft tissue measures, the treatments were not significantly different at recall. Our statement about the convexity of the profile was based on the mean tracings (Figs. 4 and 5) and on the finding that there was a significantly different net change in both the lower-lip-to-Eplane distance and the Z-angle. We should, however, have referred the reader to Table IV (rather than just to Figs. 4 and 5 and Tables II and Ill) and, in the process, we apparently should have been a bit more precise in our wording. Dr. Berg's suggestion that we might have superimposed the mean tracings of Figs. 4 and 5 on the nose and chin is of course a possibility. In the present instance, however, the chins and noses of the faces in Figs. 4 and 5 are almost superimposed as things stand. If a more exact nose/chin superimposition is required, a few minutes with some tracing paper is all that would be required of the interested reader. Finally, Dr. Berg is correct in noting that "the mean is a lonely place." It is, however, less "lonely" than any other place in a normal distribution. In any event, we would argue that, although a graphic depiction of the distribution of our data might well be of interest to some readers, our article was so long and contained so many measurements that histograms would be out of the question. Dr. Berg's basic point, however, is well taken. We would be happy, therefore, to send tables of sample standard deviations or even the raw data to readers interested in examining in greater detail the treatment variation seen here. Lyle Johnston, Jr. The University of Michigan Aml Arbor, Mi 48109-1078