Torque measures as orthodontic microimplants stability indicators

ABSTRACT

To evaluate the effectiveness of multiple torque measures in describing the stability/prognosis of Orthodontic Microimplants [OMIs] and to find the most reliable one to perform from those reported in the literature. A total of 84 OMIs [Dentos Inc, Daegu, South Korea, 7mm in length] that had the same design except the diameter were divided into 3 equal groups of 28 [SH1312, SH1413 and SH1514]. They were inserted and then removed from custom-made rigid polyurethane foam using a surgical engine and contra-angle handpiece. Multiple torque measures then were analysed and compared according to the relation between the OMI diameter and torque values. The correlation between Maximum Removal Torque [MRT] - which was taken as a reference - and other variables was tested. All statistical tests were performed at P <0.05 level of significance. All torque measures except one [Torque Ratio, TR] showed statistically significant differences between the 3 OMIs groups with the SH1514 group having comparatively the largest mean torque values then SH1413, and then SH1312 group. The correlation to MRT was significant with only TR, and although it was statistically not significant; the correlation between MRT and Maximum Insertion Torque [MIT] was increasing with the diameter increase. All of the tested measures showed the same idea at the end from statistical view and that considering any of them is feasible with no superiority of one measure over the other