Vogel L D
Division of Pediatric Dentistry, Columbia University School of Dental and Oral Surgery, USA.
N Y State Dent J. 1998 Feb;64(2):48-53.
We have heard mothers tell their children not to stick their fingers in their mouths because they will get sick. Medical and dental professionals know this is true. Oral habits like thumb sucking and nail biting can damage the structure of the mouth and can lead to the spread of infectious diseases.