Molar Intrusion in Open Bite Treatment

Open bite malocclusion is considered one of the most difficult orthodontic problems to correct because it appears as a result of the interaction of numerous etiological factors (genetic, dental, skeletal, functional, soft tissue, and habit) that contribute to its development. Various therapeutic approaches have been proposed for the treatment of an anterior open bite. These approaches vary depending on the causative factors and involve myotherapy, preventive treatment, functional therapy, orthognathic surgery, and orthodontic treatment using anterior teeth extrusion or posterior teeth intrusion. Among the non-surgical orthodontic treatment methods are the temporary anchorage devices (TADs) including miniplates and miniscrew or micro-screw implants. The intrusion of posterior teeth with temporary anchorage devices was suggested to lead to decreased lower facial height by a counterclockwise rotation of the mandible; this may resemble the orthognathic surgery outcomes for any open bite patients. To the best of the investigators current knowledge, this is the first randomized controlled trial evaluating the effect of molar intrusion in adolescence and adult patients in the permanent dentition stage.

Inclusion criteria

• Patients with skeletal open bite determined by an increased B angle (angle between the maxillary plane and mandibular plane), the Sum of Bjork and the mandibular plane angle (angle between SN plane and mandibular plane).
• Patients between 12 and 18 years old in permanent dentition stage.
• Negative over-bite of more than a mm
• Class I or Class II skeletal anteroposterior relationship.

Exclusion criteria

• Previous orthodontic treatment.
• Patients with syndromes, clefts, or craniofacial abnormalities.
• Class III skeletal anteroposterior relationship.