Babies are born with a reflex to suck any object placed in their mouth. This behaviour helps during the first few months after childbirth to establish feeding, and disappears at around four months. Ongoing thumb sucking however, is not reflexive and is believed to be a self-soothing practice.
There are usually no long-term ill-effects from thumb sucking in early childhood and most children naturally give-up the habit somewhere between 2 to 4 years of age. However, if thumb or finger sucking continues past this age it can alter the normal growth of the jaws and cause significant malalignment of the front adult teeth as they erupt into the mouth.
Common problems caused by thumb sucking that may require orthodontic attention include:
Protrusive upper front teeth - This can be a simple tooth position problem, where the upper incisor teeth are tipped forward. Occasionally, the formation of the jaw can be affected and the upper jaw and teeth will develop in a protrusive relationship to the rest of the face.
Tipped back lower front teeth - The pressure of the thumb forces the lower incisor teeth to tip towards the tongue.
Openbite - The upper and lower front teeth do not meet when the back teeth bite together. The shape of the opening between the upper and lower front teeth may match the child’s finger or thumb exactly.
Crossbite The formation of the upper jaw is too narrow for the lower jaw, so the upper and lower teeth do not fit together properly. This seems to occur as a result of the flexing of the cheek muscles during sucking.
It is important to be careful when breaking a habit such as thumb sucking. Children often use this as an emotional crutch and we must be sensitive to the psychology behind the habit. Punishment and nagging is not the best approach – patience, persistence and encouragement are essential.
Here are some tips on how to deal with thumb-sucking
Reward and offer encouragement such as a hug or praise to reinforce their decision to stop the habit.
Limit nagging as a child can become defensive.
Mark progress on a calendar for each day or week a child does not suck their thumb or finger. Provide a special outing or a toy as a reward.
Encourage bonding, such as with a special toy.
Give reminders e.g. place unpleasant tasting nail paint (available from chemists) on the fingers or thumb, put a bandaid over the thumb at bedtime.