Journal Article

Post-treatment development of the curve of Spee

Ferdinand Lie, Reinder Kuitert and Andrej Zentner

in The European Journal of Orthodontics

Published on behalf of European Orthodontics Society

Volume 28, issue 3, pages 262-268
Published in print June 2006 | ISSN: 0141-5387
Published online February 2006 | e-ISSN: 1460-2210 | DOI:
Post-treatment development of the curve of Spee

Show Summary Details


The aim of this study was to investigate the post-treatment development of the curve of Spee (CS) and to predict its post-treatment stability on the basis of cephalometric parameters. Lateral cephalograms and study models of 135 subjects (50 males and 85 females) were taken before orthodontic treatment (T1; 12.0 ± 1.5 years), at the end of orthodontic treatment (T2; 14.6 ± 1.5 years), and at least 3 years out of retention (T3; 26.6 ± 5.0 years); the curve depth (CD), location of the deepest point (LDP) of the curve, and eight cephalometric parameters were assessed. The sample was divided into a treated and an untreated lower arch group. The upper arch was treated in all patients. The sample consisted of 25 per cent Class I, 73 per cent Class II, and 2 per cent Class-III-treated malocclusions.

The results showed that the post-treatment CD was frequently unstable and unexpected changes were relatively common. The LDP was displaced distally during T1–T2 and showed mesial relocation during T2–T3. Assessment of potential predictors of the post-treatment changes in CD and LDP using stepwise regression analysis showed that a deep curve at T2 was associated with a decrease of the CD during T2–T3. A combination of distal location of the LDP with proclination of the lower incisors at T2 and extraction treatment was associated with mesial relocation of the LDP during T2–T3. The results also suggest that an optimal CD of about 2.0 mm at T2 was associated with the least amount of post-treatment change.

Journal Article.  3996 words.  Illustrated.

Subjects: Restorative Dentistry and Orthodontics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.