Orthodontic retention and relapse

Fixed retention is widely used after orthodontic treatment to prevent relapse. Definite evidence-based retention protocols after orthodontic treatment are still unavailable. Contemporary fixed retention materials are not able to ensure successful maintenance results in the long-term. Even with bonded retainers in place relapse may still occur, but also some unexpected post-treatment changes. Several biological agents have been used successfully so far to prevent orthodontic relapse in rat models, providing further insights. This project includes the following topics:

• Randomized Controlled Trials, 2- and 3-years post-treatment to evaluate the effectiveness of three different retention schemes in preventing the post-treatment mandibular arch changes in children and adolescents. The retention schemes involved: a) 0.032’’ stainless steel bonded to the lower canines only, b) 7-strand Twistflex 0.027’’ bonded to all six anterior lower teeth, c) lower removable Hawley retainer.
• Post-treatment evaluation of the short- and long-term relapse, correlation of the short- to the long-term relapse, as well as with the treatment course.
• To investigate whether the administration of a biological agent, i.e., anti-sclerostin antibodies, could affect orthodontic tooth movement and relapse, following orthodontic tooth movement in a rat model, by inhibiting bone remodeling.
• To detect biomarkers that could reliably predict post-retention relapse, in gingival crevicular fluid.

Departments:

• Department of Orthodontics

External collaborations:

• Department of Oral and Maxillofacial Diseases, University of Helsinki, Helsinki, Finland
• Biomedical Sciences Research Center “ALEXANDER FLEMING”, Athens, Greece

Publications:

• Papagiannis A, Koletsi D, Halazonetis DJ, Sifakakis I. Relapse 1 week after bracket removal: a 3D superimpositional analysis. Eur J Orthod. 2021 Apr 3;43(2):128-135. doi: 10.1093/ejo/cjaa024. PMID: 32296827.