The objective of this study was to compare the "drape" technique as proposed by Economides with the Holdaway technique in predicting post-treatment maxillary lip position and to determine which method was more accurate. Pre and post-treatment lateral cephalograms were traced for ninety (Caucasian) cases equally divided by sex into three treatment groups: a) non-extraction with at least 4mm of upper incisor retraction, b) extraction of upper first bicuspids only, and c) extraction of all first bicuspids. VTO's were constructed as outlined by Economides (drape) and Holdaway for prediction of post-treatment maxillary lip position. The predicted lip positions were compared to the actual post-treatment cephalogram and the differences measured.
The results indicated a significant difference between two prediction methods (p=.001). There was no significant difference between the two methods by age, sex, or treatment group. The drape technique demonstrated variability between treatment groups. The Holdaway prediction method proved to be a more accurate method due to its smaller mean values, less variability, and its lack of specificity to a particular treatment modality.
Michael J. Fillman
Joseph M. Caruso
Willis L. Schlenker
Master of Science (MS)
Year Degree Awarded
Date (Title Page)
Library of Congress/MESH Subject Headings
Lip -- anatomy and histology; Orthodontics -- methods; Esthetics, Dental; Forecasting
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This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.
Andrews, Kevin J., "Predicting Post-Treatment Maxillary Lip Position : A Comparison of Two Techniques" (1992). Loma Linda University Electronic Theses, Dissertations & Projects. 1313.
Loma Linda University Electronic Theses and Dissertations
Loma Linda University. Del E. Webb Memorial Library. University Archives