On the physics of the infant feeding bottle and middle ear sequela: Ear disease in infants can be associated with bottle feeding

Background: When using conventional feeding bottles, negative pressure is generated in the oral cavity, as well as, in the bottle when fluid is removed by sucking. The negative pressure inside the bottle causes the infant to suck excessively and the intraoral negative pressure may subsequently be transmitted to the middle ear via the eustachian tube. Methods: in seven infants, simultaneous pressure recordings were performed in the feeding vessel and the middle ear using three types of feeding bottles. Results: with conventional non-ventilated and under-ventilated bottles a negative pressure formed while the infant sucked and negative intratympanic pressure was frequently generated. Conclusions: it is suggested that this sequence of events may lead to secretory otitis and it's accompanying consequences. In contrast, a fully ventilated bottle showed positive pressure throughout the feeding procedure, which is similar to normal breast-feeding, and negative pressure changes were not recorded in the middle ear. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.