Svetlana Lauren's Profile

Well, re-reading the post... they do make a brace that makes thumbsucking difficult. It goes on her arm and covers the thumb.

Also, from our old dentist:

Sucking is a natural reflex and infants and young children may use thumbs, fingers, pacifiers and other objects on which to suck. It may make them feel secure and happy, or provide a sense of security at difficult periods. Since thumb sucking is relaxing, it may induce sleep.
Thumb sucking that persists beyond the eruption of the permanent teeth can cause problems with the proper growth of the mouth and tooth alignment. How intensely a child sucks on fingers or thumbs will determine whether or not dental problems may result. Children who rest their thumbs passively in their mouths are less likely to have difficulty than those who vigorously suck their thumbs.
Children should cease thumb sucking by the time their permanent front teeth are ready to erupt. Usually, children stop between the ages of two and four. Peer pressure causes many school-aged children to stop.
Pacifiers are no substitute for thumb sucking. They can affect the teeth essentially the same way as sucking fingers and thumbs. However, use of the pacifier can be controlled and modified more easily than the thumb or finger habit. If you have concerns about thumb sucking or use of a pacifier, consult your pediatric dentist.
A few suggestions to help your child get through thumb sucking:
Children often suck their thumbs when feeling insecure. Focus on correcting the cause of anxiety, instead of the thumb sucking.
Children who are sucking for comfort will feel less of a need when their parents provide comfort.
Reward children when they refrain from sucking during difficult periods, such as when being separated from their parents.
Your pediatric dentist can encourage children to stop sucking and explain what could happen if they continue.
If these approaches don’t work, remind the children of their habit by bandaging the thumb or putting a sock on the hand at night. Your pediatric dentist may recommend the use of a mouth appliance.