Molar Intrusion in Open Bite Treatment

Assessment of Skeletal and Dentoalveolar Changes Resulting From Posterior Teeth Intrusion in Treatment of the Anterior Open Bite - a Randomized Controlled Trial

This experimental study will evaluate the effect of different methods for the molar intrusion (compared with the control group) in adolescent and adult patients with open bite malocclusion. The study sample will consist of 45 patients with anterior open bite. The sample will be randomly allocated into two experimental groups, in addition to a control group. The investigators will apply a modified version of the Open Bite Appliance (OBA), by Erverdi and Usumez, for all patients in upper posterior teeth. For this purpose, miniplates will be used in the first treatment group, while miniscrews will be used in the second treatment group. In the control group, only OBA will be used. The skeletal and dentoalveolar changes occurring after intrusion of posterior teeth will be assessed by using posteroanterior and lateral cephalometric radiographs. Pre- and post- treatment changes for each group will be evaluated, in addition to the comparison of the post-treatment skeletal and dental changes that occurs between groups.

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.

The intrusion of posterior teeth using Miniplates + OBA will be performed. The investigators will apply a modified version of the OBA (Open Bite Appliance), by Erverdi and Usumez, for all patients in upper posterior teeth and miniplates. The miniplates are for Jeil Dual top® anchor system, Jeil medical corporation, #702,kolon science valley 2nd, 811, Guro-Dong, Guro-Gu, Seoul, 152-050, Korea. Tel: 82.2.850.3500. Fax: 82.2.850.3537. homepage: www.jeilmed.co.kr/ E-mail: mktg@jeilmed.co.kr

The intrusion of posterior teeth using Miniscrews + OBA will be performed. The investigators will apply a modified version of the OBA (Open Bite Appliance), by Erverdi and Usumez, for all patients in upper posterior teeth and miniscrews. The miniscrews are for Denxy ® dental orthodontic products, Denxy technology co, limited . 404,Lihuabuilding,Furongroad, Changsha, Hunan, China. Tel: 0086-731-89717339. Fax: 0086-731-82237315. Homepage: www.denxy-orthodontic.com/email: DENXYDENTALBOSS@126.COM

The intrusion of posterior teeth using OBA only will be performed. The investigators will apply a modified version of the OBA (Open Bite Appliance), by Erverdi and Usumez, for all patients in upper posterior teeth only.

The distance between the incisal edges of upper incisors and the incisal edges of the lower incisors, measured in mm

This variable will be evaluated twice; T0 before treatment, and T1 at the end of molar intrusion which will be approximately after 7 months

This variable will be evaluated twice; T0 before treatment, and T1 at the end of molar intrusion which will be approximately after 7 months

This variable will be evaluated twice; T0 before treatment, and T1 at the end of molar intrusion which will be approximately after 7 months

This variable will be evaluated twice; T0 before treatment, and T1 at the end of molar intrusion which will be approximately after 7 months

This variable will be evaluated twice; T0 before treatment, and T1 at the end of molar intrusion which will be approximately after 7 months

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.

No Individual participant data will be only available to the researchers in the department of Orthodontics, Damascus University

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