Respiração oral e função muscular respiratória

Abstract

This research aimed at assessing respiratory muscle function, electrical activity of the accessory inspiratory muscles, diaphragmatic range of movement (DROM), the palate dimensions and nasal patency in adults with mouth breathing mode (MB), comparing with adults with nasal breathing mode (NB). In the study, 77 adults were selected, from 18 to 30 years old, of both sexes, according the inclusion criteria, allocated in MB (n=38) and NB (n=39) groups. The breathing mode (MB/NB) was diagnosed, based on physical characteristics, the signs and symptoms and on the otorhinolaryngologic examination. It was evaluated anthropometric measurements, maximal inspiratory and expiratory pressures (MIP, MEP), peak nasal inspiratory flow (PNIF), spirometry, nasal obstruction symptoms (NOSE scale), vertical and transverse palate dimensions , ultrasonography of the diaphragm muscle during breathing at Tidal Volume (TV), inspiration at Lung Total Capaciy (LTC) and sniff test. Yet, it was carried out the surface electromyographic (sEMG) of the sternocleidomastoid (SCM) and upper trapezius (UT) for evaluation of the amplitude and symmetry activity (POC%) during rest, inspiration at LTC and in the sniff, MIP and MEP tests. For statistical analysis, SPSS statistical software (version 17.0) was utilized, adopting a significance level of 5 % and the tests Shapiro-Wilk (data normality), Student t and Mann-Whitney (comparison between groups), Intraclass Correlation Coefficient (inter and intra-examiner reproducibility), Pearson and Spearman (correlation between variables) and the chi-square test for nominal variables. In the comparison between groups, the MB had significantly higher mean values for NOSE scale and lower mean values for MIP, MEP, PNIF, forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and sEMG activity of SCM in the sniff, PNIF and MIP tests. There was no difference in sEMG activity during rest, inspiration TLC, as well as for the POC%. The DROM was lower in the MB group in all tests, with significant difference at rest and TLC. Palate dimensions, in the MB group, showed significantly smaller transverse distance in intercanine region and, bigger in the vertical distance at the premolars and molars regions. The PNIF correlated inversely with the NOSE scale, with the UT sEMG at rest and LTC and, positively, with the FVC, the palate transversal distance, MIP and DROM. The MIP was positively correlated with MEP and FVC. The MB group presented smaller nasal patency, smaller width and higher height of hard palate than NB. The mouth breathing reflected in the smaller values of respiratory pressures, accessory inspiratory muscle electrical activity and diaphragmatic amplitude. As smaller the nasal patency, smaller the respiratory muscle pressure, the diaphragm amplitude and the width of hard palate.