Molar Intrusion in Open Bite Treatment

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

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

Conditions
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Anterior Open Bite

Intervention / Treatment
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* Device: OBA
* Device: Miniplates
* Device: Miniscrews


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 12 Years
Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Miniplates + OBA<br>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 | Device: OBA<br>* The intrusion of posterior teeth using removable appliance OBA.<br>Device: Miniplates<br>* The intrusion of posterior teeth using temporary anchorage Miniplates.<br>|
| Experimental: Miniscrews + OBA<br>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 | Device: OBA<br>* The intrusion of posterior teeth using removable appliance OBA.<br>Device: Miniscrews<br>* The intrusion of posterior teeth using temporary anchorage Miniscrews.<br>|
| Experimental: Only OBA<br>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. | Device: OBA<br>* The intrusion of posterior teeth using removable appliance OBA.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overbite | 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 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Molar intrusion | The vertical distance between upper molars and the true horizontal plane (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 | 
| Mandibular autorotation | This variable will be measured by superimposition of the anterior cranial base. | This variable will be evaluated twice; T0 before treatment, and T1 at the end of molar intrusion which will be approximately after 7 months | 
| Anterior facial height | The distance between the point N and the point Me | This variable will be evaluated twice; T0 before treatment, and T1 at the end of molar intrusion which will be approximately after 7 months | 
| Change in the anteroposterior position of the point B | The horizontal distance between point B and the true vertical plane. | This variable will be evaluated twice; T0 before treatment, and T1 at the end of molar intrusion which will be approximately after 7 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Open bite, Molar intrusion, Temporary anchorage devices