2. The upper and lower front teeth may not approximate with each other.
3. The upper front teeth may flare out.
4. The open bite or lack of approximation of upper and lower front teeth may result in speech difficulties during pronunciation.
5. As a result of the flared out or protruding front teeth the child may end up fracturing these teeth 
    more often.
6. Protruding and uneven teeth change the facial  appearance. This can cause an inferiority complex in 
   the young mind.

DIAGNOSIS
Any child above the age of 4 with protruding anterior teeth may be affected by thumb sucking. A detailed history about the habit is very helpful. The frequency and duration of this habit can help in evaluating the extent of the habit.
 
The thumb used by the child normally appears to be very clean compared to the other finger.

TREATMENT
It can be treated by psychological methods also.
 
1. Psychological Method: 
The child is guided by the dentist and parent to consciously put an end to the thumb sucking habit over a period. This is possible only if the child is psychologically willing and wants to stop the habit.

Children often combine thumb-sucking habit with other secondary habits such as hair pulling or nose probing. Frequently making the secondary habit impossible to perform can break the primary habit.

It is very important not to criticise the child. The child needs a lot of support and affection. He should be told about the ill effects of sucking the thumb to reinforce his determination to stop thumb sucking.