Análise eletromiográfica do músculo masseter em recém-nascidos a termo durante sucção no seio materno, mamadeira e copo

Abstract

The literature on orofacial muscle activity in infant feeding with the use of alternative methods for breastfeeding is scarce. When breastfeeding is difficult or impossible during the neonatal period, an analysis of muscle activity can help determine the best method for substituting it to promote the child’s development. The aim of this study was to analyze the electrical activity of the masseter muscle using surface electromyography during suction in term newborns by comparing breastfeeding, bottle and cup feeding. We conducted an observational, cross-sectional analytical study, in the rooming in care at the Materno Infantil Hospital of Goiânia-Goiás. Was carried out on healthy, clinically stable term infants. Muscle activity was analyzed using surface electromyography during breastfeeding, bottle and cup feeding. Root mean square averages (RMS) recorded in microvolts were transformed into percentages (normalization) of the reference value. The three groups were compared by ANOVA; the “stepwise” method of the multiple linear regression analysis tested the model which best defined the activity of the masseter muscle in the sample at a significance level of 5%. Participants were 81 newborns aging 1.4±0.8 days of life,equally distributed among the three groups. RMS values were lower in the bottle (44.2±14.1%) than in the breast feeding (58.3±12.7%) (p=0.003, ANOVA); cup feeding (52.5±18.2%) did not differ (p>0.05). For one gram increase in weight, RMS would increase by 0.010 units. Bottle/cup feeding would reduce RMS by 10.392 units, comparing to breastfeeding. Masseter activity was significantly higher in breastfed newborns, compared to bottle-fed newborns, which presented the lowest RMS values. Masseter activity during cup-feeding stayed in-between breast and bottle feeding, and did not significantly differ from both groups. Cup/bottle feeding significantly predicted a decreased in RMS, compared to breastfeeding.