The desire for babies to place objects in their mouths and suck is natural. Sucking is connected to eating, a life-sustaining activity, and as a result is soothing and rewarding. For some babies, the sucking habit relieves boredom. For others, it can alleviate feelings of anxiety or insecurity. Whatever the difficulty, sucking can help stop feelings of fear, anger and worry.

Many parents have a love/hate relationship with their baby's desire to suck their thumb or pacifier. Among its benefits, the thumb/pacifier habit provides babies with a natural ability to soothe themselves without requiring attention from an adult. In the car or crib, thumb and pacifier sucking can be helpful. Still, both habits have significant downsides that parents find concerning. 

Why is Thumb and Pacifier Sucking a Problem?

All sucking habits mentioned above can lead to misalignment of the teeth if it continues beyond the age of about 2 to 4. In fact, sucking habits can actually influence the shape of the mouth and the formation of the roof of the mouth.

The age at which the sucking habit needs to stop in order to prevent permanent damage is different for every child. A good rule of thumb is that sucking needs to stop before the permanent teeth come in to prevent damage that requires orthodontic correction. 

Which Habit is Better?

The differences between thumb sucking and pacifier sucking are slim and not really significant from a dental standpoint. Thumb sucking exposes the child to more germs, and pacifiers are associated with increased risk for ear infection. 

Pacifiers are associated with a lower risk of SIDS (sudden infant death syndrome), but can also interfere with proper breast feeding. Thumb sucking is useful because thumbs never fall out, while pacifiers can be dropped or lost. Pacifiers can be an easier habit to break because they can be taken away, thumbs cannot.

Pacifiers have an "orthodontic" version which some experts believe to be better than traditionally-shaped pacifiers, but the benefits of these pacifiers are debatable. Thumbs, of course, have no orthodontic version. Either way, there's no metric for measuring the benefits or disadvantages of one sucking habit over the other. Both can damage the mouth, and both habits are hard to break. 

Stopping the Habit

Stopping a sucking habit takes consistency. Here are a few ways you can help your baby stop his or her habit:

• Praise. When your child isn't sucking on the object of choice, praise him or her for doing a good job 
• Rewards. Give your child rewards for not giving in to the sucking habit when under stress or feeling bored

If you have concerns about your child's sucking habit and whether or not the shape of your child's mouth is being influenced by his or her attachment to a thumb or pacifier, talk with their dentist. If you don't have a pediatric dentist for your child, it may help to seek advice from an expert.