# Biomechanical Analysis of Different Pacifiers and Their Effects on the Upper Jaw and Tongue
## 1 Introduction
A study by [PERSON] et al. also highlighted the advantages of using orthodontic pacifiers over conventional ones in the prevention of malocclusions and sudden infantdeath syndrome (SIDS) [6]. Similarly, Finite Element Analysis was employed by [PERSON] et al. [7], who analyzed the influence of three different types of pacifiers on the upper jaw: conventional (A), orthodontic (B), and breast-shaped (C). The study observed that pacifiers A and B tended to rotate in the sagittal plane, generating tension in the anterior incisors and favoring the development of an open bite. On the other hand, pacifier C showed lateral expansion, inducing tension on the midpalatal suture with less influence on the inclination of the incisors. This result could be related to the geometry of the orthodontic pacifier analyzed in the study. Furthermore, it was observed that the nipple of pacifier B had a greater contact area with the palate, both in the anterior and lateral regions. According to [PERSON] et al. [8], the greater the extent of the contact between the pacifier and the palatal surface, the greater the distributed stress. The use of pacifiers, especially when prolonged, can lead to several complications. Palatal growth can be influenced by both intra-oral pressure exerted by pacifiers and the forces generated by the tongue during sucking. Studies have shown that excessive pacifier use, especially in the first few years of life, can contribute to various craniofacial issues, including malocclusions such as open bite, crossbite, and overbite [9]. These complications can affect speech development, chewing function, and the overall aesthetics of the face. Furthermore, prolonged pacifier use can alter the natural resting position of the tongue, leading to altered tongue posture and impaired oral motor development, which can delay the transition to proper oral feeding patterns and result in difficulties with speech and swallowing [10]. In light of these concerns, the selection of an appropriate pacifier design is critical. Functional and orthodontic pacifiers have been shown to reduce the prevalence of malocclusions, such as open bite, compared to conventional pacifiers [11]. Thus, understanding the interaction between different pacifier types and the oral structures is essential for minimizing negative impacts on both the soft tissues, such as the tongue and lips, and the hard tissues, including the palate and jaw. This study aims to simulate and predict the behavior of six different types of pacifiers in their interaction with the tongue and palate using Finite Element Analysis (FEA). FEA is a powerful tool that has been increasingly utilized in recent years to study the dynamic interaction between the pacifier, the palate, and the tongue during non-nutritive sucking. The results of this analysis can provide valuable insights into the potential effects of different pacifier designs on craniofacial growth, guiding the development of pacifiers that support healthy oral development and minimizing the risk of malocclusions and other related complications [12].