Dr Brown's new PreVent™ pacifiers were developed by a pediatric dentist, Dr. John Davis, to help minimize the pressures inside baby's mouth. These pressures can sometimes create dental issues such as cross bites. Dr. Davis determined that palatal pressure could be lessened by creating an air channel in the pacifier that reduces suction and spreads apart when baby is sucking. This active channel -- the Patented Suction-Free Air Channel -- opens up as baby sucks for low pressure comfort.