Skeletal and Dental Changes With Hyrax-type Rapid Maxillary Expander Anchored to Permanent Versus Deciduous Molars

Study Overview
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Brief Summary
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The aim of the study is to compare the skeletal and dental maxillary expansion obtained with an Hyrax tooth-borne expander anchored either on the 2nd deciduous molars (V) or on the 1st permanent molars (6)

Detailed Description
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The aim of the study is to compare the skeletal and dental maxillary expansion obtained with an Hyrax tooth-borne expander anchored either on the 2nd deciduous molars (V) or on the 1st permanent molars (6). The main objective is to compare at the skeletal level the distance between the cephalometric points, right jugal (RJ) and left jugal (JR) (maxillary base). The secondaries objectives are performed at the dental level by measuring the distance between the maxillary first molars mesio-palatal cusp and the cuspids cups. Molar derotation is also assessed

Official Title
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Comparison of Skeletal and Dental Changes With Hyrax-type Rapid Maxillary Expander Anchored to Permanent (6) Versus Deciduous Molars (V) in Growing Subjects

Conditions
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Maxillary Hypoplasia

Intervention / Treatment
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* Device: Experimental group
* Device: Control group


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient coming to the dental clinic for a first orthodontic consultation in mixed dentition Patient aged 6 to 12 years Patient with a transverse maxillary deficiency requiring rapid maxillary expansion Presence of 1st permanent molars 6 and 2nd deciduous V molars with sufficient root length Exclusion Criteria: Syndromic patients (all syndromes combined: cleft lip, etc.) Patient with V or 6 with decays (or with major root resorption) Patient with oral hygiene non compatible with orthodontic treatment Failure to obtain informed written consent No affiliation to a French national medical health system Patient with a legal protection measure

Ages Eligible for Study
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Minimum Age: 6 Years
Maximum Age: 12 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: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Experimental group<br>Hyrax-type rapid maxillary expander anchored on the 2nd deciduous molars (V) | Device: Experimental group<br>* The experimental group will have a hyrax rapid maxillary expander anchored on the 2nd deciduous molars (V)<br>|
| Active Comparator: Control group<br>Hyrax-type rapid maxillary expander anchored on the 1st permanent molars (6) | Device: Control group<br>* The control group will have a hyrax rapid maxillary expander anchored on the 1st permanent molars (6)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in skeletal maxillary width before/ after rapid maxillary expansion | Difference in skeletal maxillary width measured on frontal cephs (distance between the cephalometric points right jugal RJ and left jugal JR of the Ricketts analysis) before (V0)/after (V8) rapid maxillary expansion with tooth-borne expander type Hyrax | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference of the inter-molar distance before/after | Difference before (V0) / after (V8) rapid maxillary expansion with tooth-borne expander type Hyrax of the inter-molar distance (mesiopalatal cusp) assessed on dental casts | 6 months | 
| Difference of the inter-canine distance before/after | Difference before (V0) / after (V8) rapid maxillary expansion with tooth-borne expander type Hyrax of the inter-canine distance (cuspids cusp) assessed on dental casts | 6 months | 
| Difference in the amount of molar derotation (inter-molar angle) before/after | Difference before (V0) / after (V8) rapid maxillary expansion with tooth-borne expander type Hyrax in the amount of molar derotation (inter-molar angle) assessed on dental casts | 6 months | 
| Inter-operator reproducibility | Inter-operator reproducibility assessed by the intra-class correlation coefficient | 1 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Orthodontic appliances, Orthodontic interceptive, Palatal expansion technique, Child, Dentition mixed, Tooth deciduous, Rapid maxillary expansion