Not All Pacifiers Are Created Equal: A Mechanical Examination of Pacifiers and Their Influence on Suck Patterning

Many pacifier companies advertise that their product is the "best choice" to support proper sucking, feeding, and dental development; however, very little evidence exists to support these claims. As the primary differences across pacifiers are structural and mechanical, the goals of this study were to measure such properties of commercially available pacifiers and to examine how these properties alter suck patterning in healthy, full-term infants.

Seven commonly utilized pacifiers were mechanically tested for pull and compression stiffness levels and categorized into nipple shape types based on their aspect ratio. Next, 3 pacifiers (Soothie, GumDrop, and Freeflow) with the most salient differences in pull stiffness levels with 2 different pacifier nipple types were tested clinically on 16 full-term infants (≤ 6 months old) while measuring non-nutritive suck (NNS).

A repeated measures analysis of variance revealed significant differences between NNS burst duration (p = .002), NNS cycles per burst (p = .002), and NNS cycles per minute (p = .006) and pacifier type. With each significant dependent measure, pairwise comparisons showed that the GumDrop and Freeflow pacifiers differed significantly on these measures.

Pacifier compression, pull stiffness, and nipple shape type yield different NNS dynamics. These findings motivate further investigation into pacifier properties and suck patterning in young infants.