(70) The Comparison of Surgical Outcomes Associated With the Use of Different Tension Bands in Intraforaminal Mandibular Fractures

Abstract: The parasymphysis (PS) is the third most common fracture site of the mandible. This region of the mandible is subject to forces of tension at the superior aspect and compressive forces at the inferior aspect due to muscular and occlusal influences. The use of a tension band has been advocated to counteract these tensile forces. Commonly applied tension bands include titanium plates, Erich arch bars, or stainless-steel bridle wires. Our aim was to compare outcomes associated with the application of various tension bands for treatment of PS fractures.An institutional review board (IRB)-approved retrospective review evaluated patients undergoing open reduction and internal fixation (ORIF) of mandibular PS fractures at Los Angeles General Medical Center in Los Angeles, California, from January 2016 to December 2023. Fractures located between the mental foramina were defined as PS fractures. PS fractures treated with ORIF were then subcategorized based on the type of tension band used (if any). All patients were also required to have had a follow-up of at least 2 weeks, and those patients lost early to follow-up were excluded. Patients who presented with other non-mandibular facial fractures, comminuted fractures, previous hardware infection, and pre-existing V3 paresthesia also were excluded. We compared complications including paresthesia, infection, hardware failure, malunion/nonunion, occlusal discrepancy, wound dehiscence, and their rates. We examined variables that could possibly predict tension band type using the Wilcoxon rank sum test for continuous variables and chi-square test for binary variables. We examined the relationship between tension band type and outcomes using Fisher exact tests and Firth logistic regression models.In total, 196 patients were included in the review, and 150 patients (76.5%) were treated with an Erich arch bar or 24-gauge stainless steel bridle wire as their tension band. Sixteen patients received a second titanium plate as their tension band. Fourteen patients were treated with a combination of a second titanium plate and Erich arch bar/bridle wire as their tension band. A total of 16 patients had ORIF via reconstruction plate (2.0 mm thickness or greater). Seven of these patients had a tension band of any type placed, while 9 were treated without a tension band. Total or partial edentulism was the only variable associated with the type of tension band utilized (P < .05) (Figure 1). We plotted the proportion of individuals with each outcome, by tension band, with exact 95% confidence intervals. Fisher exact tests showed that complication rate and hardware failure (P < .05) varied discernibly by tension band type (Figure 2). After adjusting for edentulism in our exact logistic regression models, complication rates for the various types of tension bands were not statistically significant for paresthesia, infection, malunion/nonunion, wound dehiscence and occlusal discrepancy (Figure 3). Compared to those who received Erich arch bar or bridle wire for their tension bands, those with second titanium plates were 10.52 times as likely to have hardware failure (either plate), and those with a combination of Erich arch bar/bridle wire plus secondary plate were 0.16 times less likely to have complications.Our findings suggest that the utilization of Erich arch bar/bridal wire and secondary titanium plate as tension bands can be combined to result in lower complication rates in open treatment of PS fractures. Operators must weigh the risks associated with the use of different types of tension bands along with their material costs and potential increases in operating time.References1. Saluja H. et al. A comparative evaluation of different treatment modalities for parasymphysis fractures: a pilot study. Int J Oral Maxillofac Surg. 2012 Aug;41(8):906-11.2. Degala S, Gupta N. "Tension band wiring" a simplified approach for fracture reduction and intermittent stabilization. J Maxillofac Oral Surg. 2010 Dec;9(4):382-4.

Table 1. Predictors of Tension Band
Figure 1. Proportion of Participants with Each Outcome, with Exact 95% Confidence Intervals, by Tension Band Type
Table 2. Odds Ratios and 95% Confidence Intervals for Firth Logistic Regression Models, by Outcome