Evaluation of the Effect of Pre-bent Z-shaped Titanium Plate on Narrowing of Zygomatic Arch in L-shaped Reduction Malarplasty.

Objective: Pre-bent titanium plates are widely used for internal fixation in L-shaped zygomatic reduction. The aim is to evaluate the effect of pre-bent Z-shaped titanium plate on the narrowing of the zygomatic arch in L-shaped reduction malarplasty.

Methods: Thirty cosmetic female patients were selected and scanned using computed tomography (CT). The CT images of pre-operation (T1) and post-operation(T2) were re-established through MIMICS26.0 (Materialise). After the 2 images were registered based on the skull base, the narrowing distance (ZRN) at the posterior end of the free zygomatic arch, as well as the preoperative and postoperative cross-sectional dimensions of the zygomatic arch, were measured. The ZRN and the altitude of the pre-bent titanium plate (TA) were compared using an independent t test, and their correlation was also analyzed using the Pearson coefficient. The preoperative and postoperative longest diameter (L1) and shortest diameter (L2) of the posterior zygomatic arch were compared using a paired t test.

Results: The TA was 3.80±0.82 mm and the ZRN was 3.21±0.82 mm. The difference value was 0.59±0.41 mm, which was statistically significant. TA showed a strong correlation with ZRN (r=0.916, P=0.002). The L1 and L2 of the zygomatic arch root were slightly reduced postoperatively.

Conclusion: The pre-bent Z-shaped titanium plate does not completely correspond to the zygomatic arch narrowing distance in the actual application of L-shaped reduction malarplasty. However, it can control the narrowing distance of the zygomatic arch predictably, and achieve satisfactory surgical outcomes.