DAMAGE TO THE PRIMARY DENTITION RESULTING FROM THUMB AND FINGER (DIGIT) SUCKING

estimated that approximately 50 percent of infants at one year of age suck a thumb or finger. The number decreases rapidly by ages four to f ive years. The average age for spontaneous cessation of the habit is 3 .8 years of age. Anterior open bite is the most frequent malocclusion reported with digit sucking. In this study the authors investigated th e influence of thumb and finger-sucking in the anterior and posterior sections of the primary dentition in three age-groups: three, four, an d five years. The study population included 930 subjects. Data for the non-oral-habit group were compared with the data for the thumb and/or finger-sucking group. At all ages the frequencies of open-bite and ma xillary protrusion for the thumb and finger-sucking group were higher than the non-oral-habit group. The frequencies did not appear age-rela ted. There appeared to be an increased tendency to a permanent maloccl usion in children who continued after four years of age.