RESUMEN
The digital sucking habit have been significantly related with the malocclusions. These problems can be observed as in the deciduous and mixed as in the permanent dentition. Frequency, length, and intensity of the habit generate as a consequence: anterior open bite, retrusion of the mandible, protrusion of the maxilla, excessive overjet, labial version of the upper incisors, uprighting of the lower incisors, posterior cross bites, sometimes associated to a ogival palate, diastema between the upper incisors, and any others facial characteristics. According to various authors, when the habit persist for an extended period after the age of four years, is considered how malocclusion cause. In this case is requered the professional interference. The presentation of this study has the objective to show the clinic conduct for preventive orthodontics in face to cases who exhib harmful habits.