Three Levels of Force Application for Maxillary Protraction

Study Overview
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Brief Summary
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The aim of this study is to evaluate dentoskeletal changes concomitant with different three levels of force application for maxillary protraction in growing patients with skeletal class 3 malocclusion.

Detailed Description
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Nanda reported that numerous experimental studies on primates have shown orthopedic changes in response to extraoral forces; however, very few studies have made an attempt to analyze the different force variables and their relationship to facial sutures. In consideration of the variables, experimental and clinical studies were initiated in their laboratory in 1972. A study on protraction of midfacial bones on primates reported that the point of force application significantly influences the center of rotation of the maxilla in rhesus monkeys. Our unpublished data also show that centers of rotation are influenced by the magnitude of force. The study showed that the maxilla can be successfully protracted by means of carefully controlled forces. Based on the aforementioned data, we can hypothesize that the point of force application for maxillary protraction in relation to the center of resistance of maxilla could be utilized in order to correct skeletal class 3 malocclusions with different vertical dimension discrepancies.

Official Title
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Dentoskeletal Changes Concomitant With Different Three Levels of Force Application for Maxillary Protraction in Growing Orthodontic Patients With Class 3 Malocclusion

Conditions
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Skeletal Class 3 Malocclusion Due to Maxillary Deficiency

Intervention / Treatment
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* Device: Petit typeface mask


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: The patients will be included in the study if they have the following: An age range from 7 to 10 years. Patients diagnosed to have skeletal class 3 malocclusion due to retruded maxilla and/or combined maxillary retrusion with mild mandibular protrusion. (based on cephalometric analysis) No serious systemic diseases and/or medical treatment that could interfere with orthodontic tooth movement such as analgesics, non-steroidal anti-inflammatory drugs, and hormone supplements or antibiotics. Good oral hygiene and periodontal conditions. No evidence of craniofacial anomalies, such as cleft lip and palate or previous history of trauma, bruxism or parafunctions. No previous orthodontic or orthognathic treatment. Exclusion criteria: The patients will be excluded from the study if they have the following: Systemic diseases or medications that could interfere with orthodontic treatment. Poor oral hygiene or periodontally compromised patients. Craniofacial anomalies or previous history of trauma, bruxism or parafunctions. Previous orthodontic treatment.

Ages Eligible for Study
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Minimum Age: 7 Years
Maximum Age: 10 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 |
| --- | --- |
| Active Comparator: classic occlusal level, low point of force application<br>the point of force application for maxillary protraction is at the level of the occlusal plane. | Device: Petit typeface mask<br>* (Intraoral) Hyrax expander for maxilary sutures disarticulation through expansion, (Extraoral) Face mask for generating maxillary protraction forces and head gear face-bow to act as a connector between both intra and extra oral parts.<br>* Other names: Hyrax expander, Head gear face-bow (Denturum);|
| Active Comparator: Nasal level, Medium point of force application<br>the point of force application for maxillary protraction is at 20 mm from the occlusal plane (Nasal floor). | Device: Petit typeface mask<br>* (Intraoral) Hyrax expander for maxilary sutures disarticulation through expansion, (Extraoral) Face mask for generating maxillary protraction forces and head gear face-bow to act as a connector between both intra and extra oral parts.<br>* Other names: Hyrax expander, Head gear face-bow (Denturum);|
| Active Comparator: Infrorbital level, High level<br>the point of force application for maxillary protraction is at the level of the infraorbital foramen | Device: Petit typeface mask<br>* (Intraoral) Hyrax expander for maxilary sutures disarticulation through expansion, (Extraoral) Face mask for generating maxillary protraction forces and head gear face-bow to act as a connector between both intra and extra oral parts.<br>* Other names: Hyrax expander, Head gear face-bow (Denturum);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Amount of maxillary advancement | the increase in maxillary length (condalyon-A point) in mm using Cone Beam Computed Tomgraphy (CBCT) | 8 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| degree of maxillary rotation | the change in maxillary inclination (occlusal plane to SN line) in degrees using Cone Beam Computed Tomgraphy (CBCT) | 8 months |