Thumb sucking

# Overview
Thumb sucking is the act of putting the thumb into the mouth and rhythmically repeating sucking contact for a prolonged duration. It can also be accomplished with any piece of skin within reach (such as the big toe) and is considered to be soothing and therapeutic for the person. Thumb sucking is generally associated with babies and young children.
Children suck on objects (including pacifiers) to soothe themselves; sucking is one of a babys natural reflexes and completely typical for babies and young children.
Although some adults do suck their thumbs it is rarely performed in public, which leads many to believe that adults do not suck their thumbs at all. The private act of thumb sucking by adults is due to the fear of embarrassment or shyness. There are some stigmas attached to thumb sucking in public for adults.
Thumb sucking can start as early as 15 weeks of growth in the uterus or within months of being born. Prior to 12 weeks, the fetus has webbed digits. Most thumb-suckers stop gradually by the age of five years. Rarely does it continue into adulthood. It is not uncommon for thumb-suckers to suck both thumbs or their fingers. Finger sucking is synonymous with thumb sucking in effect and treatment, but less common.

# Dental problems
Thumb-sucking can cause problems for dental development. To prevent their children from sucking their thumbs some parents put hot sauce or sour potions on their child's thumbs  although this is not a procedure encouraged by the American Dental Association: or the Association of Pediatric Dentists . During the 1950s, parents could get a series of sharp prongs known as "hay-rakes" cemented to a child's teeth to discourage sucking.
Most children stop sucking on thumbs, pacifiers or other objects on their own between two and four years of age.  No harm is done to their teeth or jaws until permanent teeth start to erupt. The only time it might cause concern is if it goes on beyond 6 to 8 years of age.  At this time, it may affect the shape of the oral cavity or dentition.
Tips from the American Dental Association :
- Praise children for not sucking, instead of scolding them when they do.
- If a child is sucking their thumb when feeling insecure or needing comfort, focus instead on correcting the cause of the anxiety and provide comfort to your child.
- If a child is sucking on their thumb because of boredom, try getting a child's attention with a fun activity.
- Involve older children in the selection of a means to cease thumb sucking.
- The pediatric dentist can offer encouragement to a child and explain what could happen to their teeth if they do not stop sucking.
- Only if these tips are ineffective, remind the child of their habit by bandaging the thumb or putting a sock/glove on the hand at night.
Summary of Best Practices Recommendations:
- American Academy of Pediatrics : Most children suck their thumbs or fingers at some time in their early life.  The only time it might cause concern is if it goes on beyond 6 to 8 years of age or affects the shape of the child's mouth and the position of teeth.
- American Dental Association : Children suck on objects as a natural reflex; however, during and after the eruption of the permanent teeth, such sucking may cause problems with the skeletal development of the mouth and alignment of the teeth.

# Thumb sucking and sexuality
Sigmund Freud considered thumb sucking a form of sexual expression and used it to study infantile sexuality.  Passionate sucking can consume all of a child's attention, leading either to sleep or even in some cases to a motor reaction in a kind of orgasm.  Furthermore, the rubbing of certain sensitive parts of the body (such as the genitals) is often combined with sucking.  In this way children can move from thumb sucking to masturbation.
In 1919, in issue 20 of Neurologisches Zentralblatt Dr. Galant published the confession of a young woman who had not given up this activity as a child in which she described the satisfaction derived from it as analogous to sexual satisfaction.

# Media references
- The 2005 movie Thumbsucker by director Mike Mills focuses on a 17 year old teenager who has the habit of sucking his thumb. It was based on a 1999 novel of the same name by Walter Kirn.
- Walt Disney Studio's 1973 film Robin Hood portrays Prince John as an adult thumb sucker.