should I offer soother/pacifier to my newborn? As he always open his mouth widely even he is full.

I agree with Reine that it is more of a personal choice. One important thing is note would be that a pacifier should not be taken as a substitute for nurturing or feeding. Here are some useful guidelines to manage your baby’s pacifier use: - Allow your baby to choose whether or not he wants the pacifier - Offer the pacifier when you know that he is not hungry (e.g., between feedings) - Avoid using the pacifier as a way to delay baby’s feeding - Try giving your baby the pacifier before nap time - Do not tie a pacifier around your baby’s neck or attached it to the crib You can refer to this site for more useful information on pacifier use: http://www.babycenter.com/0_pacifiers-pros-cons-and-smart-ways-to-use-them_128.bc