The effects of maxillomandibular fixation on ventilatory functions in adult Nigerians

Background: Maxillomandibular fixation (MMF) is a routine procedure in maxillofacial surgery in developing countries. Aim: The aim of this study was to determine the pulmonary functions (forced expiratory volume in 1 min [FEV1], forced vital capacity [FVC], and peak expiratory flow rate [PEFR]) of adult Nigerian patients who had MMF and to find the associated changes in pulmonary functions in the postoperative period vis-à -vis pulmonary function tests among healthy adult Nigerians. Settings and Design: The study setting was the Oral and Maxillofacial Surgery Department of a Teaching Hospital in Northern Nigeria, and the study design was prospective hospital based. Materials and Methods: One hundred and six patients and 106 controls were recruited between January 2011 and December 2012. Information was obtained using a questionnaire. All study participants had their baseline lung functions measured; the treatment group in addition had their postoperative daily lung function parameters measured for the 1st week and then weekly for the next 5 weeks. Statistical Analysis: Statistical analyses were performed using the Statistical Package for Social Sciences (version 16, SPSS Inc., Chicago, IL, USA). The mean and standard deviation values of physical characteristics and ventilatory functions were determined in both men and women. The mean values were compared using Student's t-test. Statistical significance was inferred at P ≤ 0.05. Results: One hundred and seventy males and 42 females participated in the study. The control group had a mean age of 30.25 ± 9.05, weight 64.08 ± 9.90, height 1.67 ± 0.10, body mass index (BMI) 23.32 ± 3.07, basal FVC 3.70 ± 0.71, basal FEV13.16 ± 0.54, and basal PEFR8.35 ± 1.62. For the treatment group, the mean age was 30.68 ± 8.23, weight 64.91 ± 9.96, height 1.66 ± 0.10, BMI 23.21 ± 3.14, basal FVC 3.72 ± 0.69, basal FEV13.14 ± 0.51, and the basal PEFR8.18 ± 1.61. Conclusion: The postoperative mean FVC, FEV1, and PEFRvalues drop significantly by more than 50% when compared to the preoperative values in the first postoperative week with the nadir on the second postoperative day in the patients with MMF.