Neonatal sucking behavior: Comparison of perioral movement during breast-feeding and bottle feeding

Background:  The aim of the present study was to compare orofacial motion and mouth angle during breast-feeding and bottle feeding in normal infants.
Methods:  Thirteen normal infants were enrolled in the study, and feeding sessions were recorded using a digital video camera at 4 or 5 days following birth. The analysis was successfully performed for 12 infants during both breast-feeding and bottle feeding. Markers were placed at the lateral angle of the eye, the tip of the jaw, and the throat region. Jaw and throat region movements were calculated using the direct linear transformation method. The angle of the mouth was also measured.
Results:  Throat region movement was significantly larger than jaw movement in both breast-feeding (eye–throat region changes: 1.51 ± 0.37 mm, eye–jaw changes: 0.91 ± 0.31 mm, P < 0.001) and bottle feeding (eye–throat region changes: 2.91 ± 0.46 mm, eye–jaw changes: 1.77 ± 0.33 mm, P < 0.001). Jaw and throat region movements were significantly smaller during breast-feeding than those during bottle feeding ( P < 0.001). The angle of the mouth during breast-feeding is larger than that during bottle feeding ( P < 0.001). There was a negative correlation between the angle of the mouth and jaw movement.
Conclusions:  Jaw and throat region movements during bottle feeding differ from those during breast-feeding. This partly results from the difference in the angle of the mouth during feeding.