[Quality of finishing occlusion and long-term stability of orthodontic treatments with premolar extractions : A systematic review].

Studies about orthodontic relapse have always confirmed the occurrence of some occlusal changes after orthodontic treatment. The reopening of premolar extraction spaces is one of the most frequently observed movements and would have several origins : gingival folds, root proximities, muscular imbalance... and particularly unstable end of treatment occlusion. The aim of this systematic review was to study the correlation between quality of the occlusal finishing after orthodontic treatment with premolars extraction and reopening of extraction spaces. The review was undertaken according to PRISMA recommendations from the Cochrane Handbook through an electronic consultation of the PubMed database to identify clinical trials that responded to the PICO research question. Five studies met all the inclusion criteria. Three studies used the Peer Assessment Rating (PAR) in assessing the quality of the occlusal finishing. For two of these studies, there is a correlation between poor occlusal finishing and reopening of extraction space. For the other three studies, no cause-and-effect relationship between these two factors has been proven. The divergence of the published results was explained by the fact that the stability of an orthodontic treatment depends on multiple parameters. Further controlled clinical studies should be conducted to objectively evaluate, without interfering with other parameters, the role of occlusal finishing in the long-term stability of orthodontic treatment.