IntroductionMandibular fractures have significant influence on oropharyngeal and laryngopharyngeal portions of the upper airway. They can be managed by MMF or ORIF.Aim & ObjectivesTo quantify and compare the effects of MMF with ORIF on the pulmonary functions of the patients undergoing treatment for mandibular fractures.MethodTotal 42 patients with isolated mandibular fractures were randomly divided into two treatment groups. Group A comprised of 21 patients planned for ORIF under LA and Group B comprised of 21 patients planned for MMF under LA. Pulmonary function tests (PFT) were done in all participants preoperatively 24 h before, postoperatively after 24 h, 1 week, 4 weeks and 6 weeks using spirometry. FVC, FEV1, FEV1/FVC, and PEFR were determined and compared.ResultsPFT values in both the groups were comparable preoperatively 24 h before and were significantly lower than their predicted values showing adverse effect of mandibular fractures on airways. Postoperatively after 24 h, 1 week and four weeks, PFT values were significantly lower in group B (MMF) than in group A (ORIF). At six weeks postoperatively, when MMF was removed, there was no statistically significant difference in PFT values of both the groups.ConclusionMandibular fracture patients presented with abnormal PFT values. Patients treated by MMF had obstructive pulmonary pattern, while those treated by ORIF had normal pulmonary pattern concluding that MMF can be dangerous to the patients with limited respiratory reserve and the use of ORIF in pulmonary comorbidity is justified.