Efficacy of drill free screws vs self tapping screws in zygomatico maxillary complex fractures – a randomized controlled trial

Purpose: To compare the efficacy of drill free screws and self tapping screws in the fixation of zygomatico maxillary complex fractures. Materials and Methods: A prospective randomized comparative study was planned comprising of 18subjects, underwent fixation of zygomatico maxillary complex fracture. The subjects were block randomized into two groups—group a fixation using miniplates and self tapping screws and group B fixation using miniplates and self drilling screws. Intra operatively operating time, screw fixation time, fixation at operation, state of reduction at operation were evaluated. Postoperatively occlusal discrepancy, segmental mobility, anatomic reduction and signs of infection were evaluated. Chi square test and independent t test was used for Statistical analysis. Results: The mean operation time for fixing mini plates using self-tapping screws was 130(SD=15.61) seconds whereas for drill free screws was 108(SD=23) seconds. The mean screw fixation time for fixing mini plates using self-tapping screws was 337.2(SD=39.37) seconds whereas for drill free screws was 284.3(SD=104.94) seconds. The differences in measurements of fixation at operation, state of reduction at operation occlusal discrepancy, segmental mobility, anatomic reduction between 2 groups were not statistically significant. Post operative signs of infection was also not statistically significant among the 2 groups. Conclusion: On analysing the results of our study, apart from the operating and fixation time, the drill free and the self tapping screws are equally effective in terms of stabilization of fractures clinically and radiologically, intra-operative ease of handling and recording, intraoperative technical challenges and post operative complications. To conclude, drill free screws can be used as an alternative to self tapping screws in fixation of zygomatico maxillary complex fractures as the efficacy of both the screws was found to be equally effective. In our study, the sample size was limited and thus further studies are to be done in future to evaluate the efficacy of drill free screws.