http://http://www.drbrownsbaby.com/pacifiers-teethers/pacifiers Developed by a pediatric dentist, Dr. Brown's PreVent pacifier helps minimize the pressures inside baby's mouth. These pressures can sometimes create dental issues such as cross bites. Palatal pressure is lessened by creating an air channel that reduces suction and spreads apart when baby is sucking. This Patented Suction-Free Air Channel opens up as baby sucks for low pressure comfort. Patented pacifier design from a pediatric dentist • Suction-Free Air Channel helps reduce suction and palatal pressure • Soft, suction-release bulb spreads wider as baby sucks for low pressure comfort • Helps to lower the pressures inside the mouth that can create dental issues, such as cross bites • Thin-stem design is minimally intrusive on baby's mouth • Available in 3 sizes: 0-6 Months, 6-12 Months, 12+ Months