# A Comparative Assessment of Right-Angle Screwdriver Versus Conventional Screwdriver for Orthognathic Surgeries

## TL;DR

This study compares right-angle and conventional screwdrivers in orthognathic surgery, finding that the right-angle tool improves fixation and reduces challenges in posterior drilling.

## Contribution

The study introduces a comparative assessment of right-angle screwdrivers in orthognathic surgery, highlighting their ergonomic and clinical advantages.

## Key findings

- Right-angle screwdrivers showed significantly easier fixation compared to conventional ones (p-value < 0.001).
- Surgical time was reduced with right-angle screwdrivers, though the difference was not statistically significant (p-value 0.13).
- Screw angulation with right-angle tools was more consistent and perpendicular to the bone (p-value < 0.001).

## Abstract

Background

Bilateral orthognathic surgery is one of the unique and challenging orthognathic surgeries that gained popularity after numerous modifications to the techniques. Using linear equipment inside the oral cavity might lead to malalignment or structural weakness due to incorrect placement, making the ramus osteotomy more difficult. By directly positioning the instrument perpendicularly over the mandibular ramus region, a right-angle drill can help promote a more ergonomic approach.

Objectives

The primary objective was to compare the efficacy of a right-angle screwdriver over a conventional screwdriver for orthognathic surgery using clinical parameters. The second objective was to assess the ease of fixation, the ease of osteotomy, and the time taken for the surgery in both groups.

Methods

This prospective observational study, comparing the effectiveness of conventional and right-angle screwdrivers for orthognathic surgery, was carried out on 12 patients. A split-mouth design was chosen. For the 12 patients, a right-angle screwdriver was used to secure the right mandibular plate and screw, while a traditional straight handpiece was used to fix the left plate and screw. Clinical parameters such as the ease of osteotomy, the ease of fixation, the time taken for fixation, and the postoperative angulation of the screw in relation to the bone with cone beam computed tomography were evaluated. The procedure was communicated to the patients, followed by obtaining written informed consent.

Result

Statistical analysis was done using descriptive and inferential statistics using an independent sample t-test and an unpaired t-test. IBM SPSS Statistics for Windows, Version 26.0 (Released 2019; IBM Corp., Armonk, NY, USA), was used. The level of significance was set at a p-value of <0.05. Compared to a conventional screwdriver, the right-angle screwdriver made osteotomies and fixations easier for 12 patients and also required less surgical time. Statistically, it was shown that ease of fixation had a statistically significant difference among right-angled and conventional screwdrivers (p-value < 0.001), whereas time taken had an insignificant difference (p-value 0.13). The angulation of screw fixation with the right angle showed a consistent result of fixation perpendicular to the bone when compared with conventional screwdrivers providing stable fixation, which was statistically significant (p-value < 0.001).

Conclusion

Compared to the conventional screwdriver used in orthognathic procedures, the right-angle screwdriver ensures solid fixation and eliminates the challenges encountered while drilling and screwing posteriorly positioned screws.