# Customized z-shaped versus conventional miniplates for fixation of parasymphyseal/body mandibular fractures: a randomized controlled trial evaluating clinical and radiographic outcomes

## TL;DR

A study compared customized Z-shaped miniplates with conventional ones for fixing jaw fractures and found similar clinical outcomes but shorter operation time with the Z-shaped plates.

## Contribution

The study introduces customized Z-shaped miniplates as a potentially more efficient fixation method for mandibular fractures.

## Key findings

- Customized Z miniplates had significantly shorter operation time compared to conventional miniplates.
- No significant differences were found in bone density, pain, occlusion, or mental nerve affection between the two groups.
- Both methods showed similar clinical and radiographic outcomes for mandibular fracture fixation.

## Abstract

Mandible is considered the protrudest mobile bone of the facial skeleton so it is the most common maxillofacial fracture. Customized Z miniplate is a new geometry that may provide better mental nerve preservation, healing of fractures compared with conventional two miniplates in the treatment of parasymphyseal/body mandibular fractures.

To compare between customized Z miniplates and conventional miniplates for fixation of parasymphyseal and body mandibular fractures in terms of bone density (primary outcome), post operative mental nerve paresthesia, pain, occlusion and operation time (secondary outcomes).

This prospective, parallel, exploratory, randomized controlled study was conducted from April to December 2024 and included 22 patients diagnosed with parasymphyseal or body mandibular fractures. Allocation (customized Z-miniplates, n = 11; two miniplates, n = 11) was done by independent statistician using a computer-generated random number list method. Mann-Whitney U, Wilcoxon-signed rank and Chi-square tests were applied (p < 0.05). Postoperative patient evaluation was done for primary outcome (bone density) and for secondary outcomes (nerve paresthesia, postoperative pain, occlusion and operation time). All adverse events were recorded prospectively during follow-up visits. The trial was registered retrospectively at ClinicalTrials.gov (NCT07094867) due to administrative procedures, which represents a potential source of bias.

Statistical analysis did not detect significant variation in terms of mean bone density, occlusion, mental nerve affection and pain between customized Z miniplates and conventional two miniplates. Operation time was statistically significant shorter in customized Z miniplate group (p < 0.001). Only one case of wound dehiscence occurred in each group and no other complications observed.

Both fixation methods provided results that were not statistically distinct in terms of pain, occlusion, mental nerve affection and mean bone density, with significant shorter operation time for parasymphyseal/body mandibular fracture fixation. Given the sample size, our study provides preliminary findings of clinical and radiographical performance of customized Z plate.

The research was formally recorded in the clinicaltrials.gov database with registration submitted on 06/27/2025 under the number (NCT07094867).

The online version contains supplementary material available at 10.1186/s12903-026-07671-6.