Thumb sucking habits are considered within a broad category of habits that include finger-sucking. Thumb sucking and finger sucking are more generally termed as ” digit sucking “.

It is a normal habit which gives the baby a feeling of security, pleasure and considerable satisfactions during the first year of life. It starts developing in the oral stage of the child’s development. With the growth of the jaws and the development of the muscles, the infant learns to suck by coordinating mandibular movements and muscular activity. Sucking is the first coordinated muscular activity of the infant which enables bottle feeding.

There are essentially 2 forms of sucking :

1.  Nutritive sucking : Bottle
2. Non-nutritive sucking : Thumb, Digit, Blanket or Toy

Children who are not satisfied by nutritive sucking adopt non-nutritive sucking to satisfy their need for security. Thumb sucking is the earliest and most common habit in children affecting as many as 46 % children. If the kid chooses this habit in the early year it should not be discouraged. The parent or care giver can try gently moving the infant hand away from the mouth that is an attempt to interest him or her in his/her favourite toy. The parent can also try to encourage the use of a pacifier as an alternative to thumb sucking.

After age two, thumb sucking usually decreases, appearing only at bedtime or when the child is under stress or overly tired. Gradually it will stop altogether. There are 2 types of thumb sucking.  Active and Passive. Passive thumb sucker places the thumb in the mouth , exerting no undue pressure and causing no bony changes. Active thumb sucker exerts, heavy vigorous pressure with the thumb against the dentition and when this habit is continued for prolonged period of time it can affect the position of the erupting permanent teeth and the shape of the jaws. Active thumb sucking may also interfere with the child’s speech patterns.

Associated Dental Problems :

The effects of sucking habits on the dental arches and teeth depends on several factors :

• Frequency of habit
• Duration of habit
• Osteogenic Development
• Genetic endowment
• Child’s state of health

The damage is reportedly associated with this habits including anterior open bite, posterior cross bite, exaggerated overjet and overbite, TMJ problems, diastemas, retrusive positioning of mandible and etc. The relation to malocclusion is particularly evident in children continuing the habit beyond the age of 4 years. During thumb sucking, there is upward pressure of the thumb against the maxillary incisors which may retard their eruption. Also, due to the sucking action force exerted by :

• Masseter
• Orbicularis oris
• Mentalis
• Buccinator
• Superior Pharyngeal Constrictor
• Pterygomandibular Raphe

This leads to constriction of the maxilla, subsequent “V” shaped palate leading to a posterior crossbite. The pressure exerted by the wrist against the chin could also retard developement of mandible probably leading to “Angle’s Class II” malocclusion. These changes have been known to regress after the habit has stopped.

Treatment of Thumb Sucking At Home

Parent-directed measures for a young child (around age 4)

1. Give your child more attention and distract him or her with engaging activities.
2. Limit the places and times for thumb-sucking. For example, ask your child to do it only while in his or her bedroom.
3. Put away items (such as blankets) that your child associates with thumb-sucking. At first, put the items away for short periods of time throughout the day. As your child learns other ways of self-comfort, gradually increase the amount of time these items are not available.

Measures where the child takes an active role (beginning around age 5)

1. Talk to your child openly about the effects of thumb-sucking.
2. Put gloves on your child’s hands or wrap the thumb with an adhesive bandage or a cloth. Explain that the glove, bandage, or cloth is not a punishment, but is only there to remind him or her not to thumb-suck.
3. Develop a reward system, such as putting stickers on a calendar to record each day that your child does not suck his or her thumb. After an agreed-upon number of days, have a celebration for your child.
4. Use a special nontoxic, bitter-tasting nail coating, such as Thum. Apply it like fingernail polish to the thumbnail (or fingernail) each morning, before bed, and whenever you see your child sucking his or her thumb. This treatment is most successful when it is combined with a reward system.Before you start any home treatment for thumb-sucking, make sure you feel comfortable and confident with your plan. Also, make sure your methods will be consistently used by other people who care for your child.

   When attempting to get your child to stop thumb-sucking:
   You should not remove the thumb from the child’s mouth while he or she is awake. You can remove it after the child is asleep.

5. Do not punish or shame your child for thumb-sucking. Stay neutral, calm, and nonjudgmental when talking about your child’s thumb-sucking habit.
6. Do not allow other people to make fun of your child.If home treatment methods have not worked and you are concerned or feel frustrated about your child’s thumb-sucking, talk with a doctor.