Thumb sucking is the most common oral habit with associated damaging dento-facial effects such as anterior open bite, poor esthetics, speech difficulty and bad psychological impact. This entails careful examination of the habit for proper diagnosis and treatment plan. Management of thumb sucking habit can be performed by many habit breaking appliances such as palatal crib, palatal spurs and blue grass appliance, however, these appliances have many drawbacks such as difficulty of speech and eating, poor esthetics and injury to tongue or thumb. These shortcomings might affect patient compliance and call for a new habit breaking appliance that can efficiently break the habit with better patient acceptance.This report describe the management of 8 years old male child with thumb sucking habit and anterior open bite. Comprehensive diagnosis was performed and patient’s records were taken (Extra-oral and intra-oral photographs, lateral cephalometric and panoramic radiographs, and study models) along with impression for appliance’s fabrication. When received from the laboratory, the appliances were disinfected, fitted then cemented and adjusted in the patient’s mouth. The patient and his parent were enlightened about the advantages of the appliances, which entailed cessation of thumb sucking habit thus allowing tooth eruption and bite closure, and giving them the instructions at time of appliance insertion. A questionnaire to test patient compliance was given to the parents every follow up. Treatment was consummated once the child ends 12 months of follow up regardless the fact that it could be achieved.

Treatment effects were evaluated by comparing pre and post treatment records along with the questionnaire answers. The report showed the patient was compliant with the appliance, with significant increase in overbite and the maxillary intercanine width. This might be the result of stop of thumb pressure on the palate. It also showed a significant reduction of lower anterior facial height. The maxillary incisors had been uprighted. The interlabial gap greatly reduced after treatment while the nasolabial angle recorded no significant change. It was concluded that the magnetic habit breaker was effective to stop the habit and help bite closure due to the appliance's dual effect and good patient acceptance.

Keywords: Anterior open bite; thumb sucking; habit breaking appliance; magnetic habit breaking appliance