Some babies come to depend on their dummies, but they can damage teeth and cause speech problems
Earlier this year, Katie Holmes's daughter, Suri Cruise, was photographed sucking on a dummy. The child, who turned five in April, unwittingly caused a debate on parenting websites about what age children should quit the habit - or whether they should even start it in the first place.
Babies are given rubber, plastic, or silicone nipples because infants find great comfort in sucking - a primal instinct that enables them to feed. A form of pacifier dates back as far the early 1300s and was illustrated in a Madonna and child painting by Dürer in 1506.
But how bad are they for babies and children in the long run? Most dentists would tell you to avoid giving your child a dummy beyond the age of six months as they can damage teeth.
"It creates a gap between the bottom row of teeth and the top, called an anterior open bite," says dentist Sara Geneen.
"The condition makes it difficult to chew and from a cosmetic perspective it can cause the teeth to protrude. It's a very difficult thing to treat orthodontically but if you drop the habit early it will correct itself. The teeth will come down again.
"If the dummy is in for too long it's something you have got to try and correct with braces. I would recommend to get rid of it sooner rather than later as the longer the child uses it, the more dependent he or she becomes."
Geneen says she does not mind if parents tell their child they are giving the dummy to the dentist, so that she is seen as the bad guy in the midst of any dummy-disappearing distress. She does however admit that dummies do have advantages over thumb-sucking, for example.
"The benefits of the dummy are that you can just get rid of it if you have to, whereas you can't with a thumb," she says. "And there's more chance of protruding teeth as the thumb presses on them."
Meanwhile, speech and language therapists are equally reluctant to encourage dummy use. Research shows that children who suck their fingers or thumbs, or who use a dummy for at least three years, are three times more likely to have a problem with their speech.
"If the dummy is not used judicially a child may not produce the sounds that are made when the tongue tip is placed behind the top teeth - T, D and S," says speech and language therapist Sue Addlestone. "Instead they're being made at the back of the mouth. It does depend how often the dummy is used but it is the most common speech problem. I don't always say it's definitely because of dummy use as that would put too much guilt on the parents, and once the damage is done it doesn't really matter."
Addlestone has tips for weaning a child off the dummy: "Try and limit it to bedtime rather than during the day. If the child is three or four when it is withdrawn, and becomes distressed, try a reward system like star charts. I have found them to be very successful."
But do not be too quick to pull the dummy straight out of your crying infant's mouth. There is evidence to suggest that dummies help to soothe colic (a common infant indigestion problem) and recent studies prove that they halve the risk of cot death in newborn babies, so it may be worth delaying removal until your baby starts teething.