Side Effects of Thumb Sucking

According to the Palo Alto Medical Foundation for Health Care, Research and Education, thumb sucking is normal and soothing in babies and young children. Thumb sucking can be the result of hunger, boredom, nervousness or tiredness. Most children stop sucking their thumbs between the ages of 3 and 6. For children who continue to suck their thumbs as their permanent teeth are beginning to come in, there are possible negative side effects.

A baby sucking her thumb. (Image: Brand X Pictures/Stockbyte/Getty Images)

Dental Problems

Dental problems can occur from extended thumb sucking. A child's teeth may not align properly (malocclusion), or the teeth may be pushed outward causing an overbite. The roof of the mouth may become malformed. Depending on the severity of these issues, treatment from an orthodontist may be needed.

Speech Difficulties

Speech difficulties are a possible side effect of thumb sucking that continues after the permanent teeth are appearing. Teeth alignment problems cause certain sounds distortions, according to SpeechPathology.com. Additionally, long-term thumb sucking may slow the replacement of tongue thrust, a normal early childhood swallowing pattern, with the mature swallow. The sounds and letter that may be impacted include /s, z, t, d, l, n/, /S, and dz. A lisp may also be an effect of thumb sucking that extends into the school years.

Germs Spread

Germs are spread through thumb sucking. Children that continue thumb sucking into their school years pick up and spread germs through their thumb sucking.

Infected Thumbs

Children that suck especially hard on their thumbs may create sores and infections.

Peer Teasing

Children that continue thumb sucking into elementary school or beyond are at risk of being teased. Thumb sucking is thought of as a baby or toddler activity, so children who suck their thumbs beyond that age may be subject to comments and ridicule from peers.