Comparative Evaluation of Anchorage Loss with Implant-Aided Retraction and Frictionless Mechanics with Conventional Anchorage in Bimaxillary Protrusion Cases.

Management of anchorage and good control of molars in all three planes of space is necessary for optimal results. It is of paramount importance for the clinician to select the appropriate anchorage control. The aim of the study was to compare the anchorage loss from implant-aided retraction and frictionless mechanics retraction in bimaxillary protrusion cases. Cephalograms of 40 patients were evaluated in this retrospective study, segregated into two groups based on their retraction mechanics. Anchorage loss was determined from measurements made on pretreatment and postretraction lateral cephalograms. Mean and standard deviation from independent sample t-tests were used to analyze the anchorage loss between the two groups. Statistical analysis was carried out using SPSS version 20.0. In the implant-aided group, mean anchorage loss was 0.95 +/- 0.36 mm; in the frictionless mechanics with conventional anchorage group, the mean anchorage loss was 2.44 +/- 0.46 mm. The average interincisal angle in the frictionless mechanics group and the implant-aided retraction group was 99.45 +/- 5.41 degrees and 100.15 +/- 4.85 degrees , indicating similar incisor inclinations in the pretreatment group. Pretreatment interincisal angle measurement ensured that both groups had similar anchorage demands. Anchorage loss was greater in frictionless mechanics with conventional anchorage (2.44 m) when compared to implant-aided retraction mechanics (0.95 mm). Implant-aided retraction can thus be considered for cases requiring absolute anchorage.