Effects of maxillomandibular fixation and rigid internal fixation on pulmonary function in patients with mandibular fractures

Abstract

Closed reduction and maxillomandibular fixation (MMF) is associated with airway obstruction. The ventilatory effect of open reduction and rigid internal fixation (ORIF) as an alternative treatment has not been determined. The aim of this study was to compare the effects of MMF and ORIF on pulmonary function (PF) in patients with mandibular fractures. Using a computer-generated simple randomization protocol, 40 eligible participants were allocated to MMF and ORIF treatment groups. PF tests were done preoperatively and at 24hours, 1, 6, and 7 weeks postoperative in all participants in both groups, using a portable office spirometer (Spirobank G). Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC, and peak expiratory flow rate (PEFR) were determined. At 6 weeks postoperative, PF tests were performed after the release of MMF. PF tests in the MMF and ORIF groups were similar preoperatively. At 24hours postoperative, FEV1/FVC was significantly lower in the MMF group than in the ORIF group (p<0.001). Values of FEV1 (p=0.022), FEV1/FVC (p=0.001) and PEFR (p<0.001) were significantly lower in the MMF group than in the ORIF group at 1 week postoperative. While MMF negatively impacted on PF, ORIF had no adverse effect on PF.