Accuracy of reduction and postoperative symmetry assessment of customized z-shaped miniplates versus conventional miniplates in mandibular fractures treatment: a randomized controlled clinical trial

Background Mandibular fractures are common facial injuries requiring precise reduction to restore function and aesthetics. Conventional fixation methods not always achieve optimal postoperative symmetry. Aim of the study To objectively evaluate and compare the radiological outcomes of customized Z-shaped miniplates versus conventional two-miniplate fixation using five computed tomography -based digital methods. Also, operative time was recorded. Materials and methods A prospective, parallel, randomized controlled superiority trial included 22 patients of both genders, with unilateral parasymphyseal/body mandibular fractures. Allocation (customized Z-miniplates, n = 11; two miniplates, n = 11) was done by independent statistician. Mann-Whitney U, Wilcoxon-signed rank and Chi-square tests were applied ( p < 0.05). Results Mean operative time was significantly reduced at study group ( p < 0.001). Symmetry quantitative assessment showed smaller postoperative differences in the study group ( p < 0.05). Symmetry evaluation by Asymmetry Index equation revealed significant improvement at points Co and La ( p < 0.05), while points Go and MF showed no significant changes ( p > 0.05). Accuracy of reduction quantitative assessment demonstrated significant smaller postoperative values in study group ( p < 0.05). Evaluation of reduction accuracy by chromatographical analysis (quantitatively) showed smaller values at all bilateral landmarks in study group ( p < 0.05), except La point on fractured side ( p = 0.3), while (qualitatively) showed more green areas in study group. Conclusion Customized Z miniplates demonstrated superior postoperative symmetry, higher reduction accuracy and shorter operative time compared with conventional miniplates. Given the sample size, these findings should be interpreted as preliminary evidence supporting potential clinical efficiency of customized Z miniplates in the management of parasymphyseal/body mandibular fractures. Trial Registration This study is retrospectively registered at clinicaltrials.gov with initial release at 06/27/2025 under the number (NCT07094867), Where the trial protocol and statistical analysis plan can be accessed.