Evaluation of the Treatment Effects of Tooth Borne Versus Bone-anchored Protraction Procedures in Class III Patients With Maxillary Deficiency

Study Overview
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Brief Summary
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The aim of this prospective randomized controlled clinical study is to compare the effects of bone-anchored and tooth borne maxillary protraction on dentofacial structures in skeletal Class III patients.

Detailed Description
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Today, the treatment of class III malocclusion is becoming more important due to the increased awareness of people about their appearance and the impact of appearance on the psychosocial state. Various studies have shown that 40% of class III malocclusions are clinically caused by maxillary deficiency, 42% by mandibular excess, and 18% by a combination of maxillary deficiency and mandibular excess. The face mask is the most effective treatment modality for class III malocclusions caused by a maxillary deficiency. The rationale for using a face mask is to apply heavy forces to the midface to advance the maxilla forward. These forces cause disarticulation by initiating resorption and apposition in the sutural articulations. However, undesirable dental effects arise from the use of tooth-borne rapid maxillary expansion (RME) during these treatments. These include loss of anchorage and incisor proclination during the mesialization of the maxillary dentition, extrusion of the upper molars and posterior mandibular rotation, and insufficient anterior displacement of the maxilla (1-3 mm). Studies have shown that increasing the skeletal effects can reduce post-treatment relapse, one of the most important problems in orthodontics. To increase the amount of maxillary skeletal advancement and to minimize the side effects of tooth-borne maxillary expansion and protraction, a new bone-anchored hybrid hyrax appliance has been proposed. Hybrid hyrax treatment has the following advantages over tooth-borne mechanics: Since the force is applied close to the center of resistance of the maxilla, counterclockwise rotation of the maxilla and related posterior mandibular rotation are not observed. Transversal forces are applied to premolars or deciduous molars and mini implants without the risk of periodontal damage, fenestration, and dehiscence that may occur with tooth-borne appliances are avoided. Mesial migration of the dentition, proclination of the upper incisors, and occupation of the necessary place for the canines to erupt are avoided. Treatment is minimally invasive. Upper and lower arches remain completely accessible for orthodontic interventions. Only skeletal maxillary advancement is achieved. In our study, additionally, the Alternate Rapid Maxillary Expansion and Constriction (AltRamec) protocol, which increases the skeletal effects during maxillary protraction by providing more effective disarticulation of circummaxillary sutures than conventional rapid maxillary expansion was used.

Official Title
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Evaluation of the Treatment Effects of Tooth Borne Versus Bone-anchored Protraction Procedures in Class III Patients With Maxillary Deficiency

Conditions
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Class III Malocclusion, Maxillary Deficiency, Anterior Crossbite

Intervention / Treatment
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* Other: Face mask with hybrid-hyrax
* Other: Face mask with conventional bonded RME


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Late mixed or early permanent dentition C3 or C4 period according to the cervical vertebral maturation method Presence of skeletal class III malocclusion (ANB <0 °). Retrusive nasomaxillary complex (Nperp-A <1 mm). Presence of dental class III malocclusion Normal or horizontal growth pattern (SNGoGn <40 °). Negative overjet (overjet <0) Good cooperation Absence of any systemic disease Periodontal health No previous orthodontic treatment No craniofacial deformity No neuromuscular deformity The absence of a congenital anomaly Exclusion Criteria: Poor cooperation Early mixed dentition Individuals who have passed the C4 period Craniofacial deformity Congenital anomaly A history of facial trauma Syndromes such as cleft lip and palate

Ages Eligible for Study
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Minimum Age: 10 Years
Maximum Age: 13 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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: Bone-anchored maxillary protraction group<br>Face mask with hybrid-hyrax | Other: Face mask with hybrid-hyrax<br>* Face mask with hybrid-hyrax<br>|
| Experimental: Tooth-borne maxillary protraction group<br>Face mask with conventional bonded RME | Other: Face mask with conventional bonded RME<br>* Face mask with conventional bonded RME<br>|
| No Intervention: Control group<br>Control group consisting of 14 non-treated Class III malocclusion subjects | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pre-treatment (T0) cephalometric analysis measures | A cephalometric analysis of skeletal maxillary (SNA) and mandibular (SNB) positions | 0 month | 
| Pre-treatment (T0) soft tissues measurements | Maxillary and mandibular (Soft tissue convexity angle) soft tissue analysis using 3D stereophotogrammetry | 0 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-treatment (T1) cephalometric analysis measurements | Evaluation of pos-treatment cephalometric changes of skeletal maxillary (SNA) and mandibular (SNB) positions | An average of 6 month | 
| Post-treatment (T1) soft tissues measurements | Evaluation of maxillary and mandibular soft tissue changes (Soft tissue convexity angle) using 3D stereophotogrammetry | An average of 6 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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rme, hybrid hyrax, maxillary protraction, tooth-borne vs bone-anchored, face mask, AltRamec, Temporary anchorage devices (TADs) in the anterior palate