With the baby bottle, the child does not close his/her lips as strongly and the lips adopt an “O” shape, the tongue’s activity is decreased, as it moves forwards against the gums to regulate the excessive flow of milk. Oral motor activity decreases, a factor that will not favour a harmonious bone and cartilage development.
The flow of milk in the baby bottle does not require a constant movement of the jaw, which persists in its rearmost position (distal). The bottle stimulates muscles, though the wrong ones (buccinators), which can generate narrow dental arches and consequently a lack of space for the teeth and the tongue. When the baby drinks from a baby bottle, sucks a pacifier or a finger, the tongue does not reach its correct position in the palate.
Therefore, the object that lies between the palate and the tongue, influences the height and the width of the palate.
With all these factors, the establishment of an early atypical (incorrect) deglutition is highly probable, which can subsequently cause different types of malocclusion (incorrect bite).
During decades, the bottle (particularly during the night: nocturnal feeding) has been associated with early childhood caries (previously called “baby bottle tooth decay”) because the contents of the bottle usually stay in the mouth for a long time, causing the demineralization of the dental enamel.