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

Not Applicable

Completed

• Conditions: Maxillary Hypoplasia
• Interventions: Device: Experimental group; Device: Control group

• Registration Number: NCT05773573
• Lead Sponsor: University Hospital, Montpellier

Brief Summary

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

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

Study Timeline

• Study First Submitted: 2023-03-06
• Study First Submitted QC: 2023-03-06
• Study First Posted: 2023-03-17
• Study Start: 2023-05-22
• Primary Completion: 2024-12-20
• Status Verified: 2025-01
• Study Completion: 2025-01-15
• Last Update Submitted: 2025-01-15
• Last Update Posted: 2025-01-17

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 34

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Experimental group	Experimental group	Hyrax-type rapid maxillary expander anchored on the 2nd deciduous molars (V)
Control group	Control group	Hyrax-type rapid maxillary expander anchored on the 1st permanent molars (6)

Primary Outcome Measures

Name	Time	Method
Difference in skeletal maxillary width before/ after rapid maxillary expansion	6 months	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

Secondary Outcome Measures

Name	Time	Method
Difference of the inter-molar distance before/after	6 months	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
Difference of the inter-canine distance before/after	6 months	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
Difference in the amount of molar derotation (inter-molar angle) before/after	6 months	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
Inter-operator reproducibility	1 month	Inter-operator reproducibility assessed by the intra-class correlation coefficient

Trial Locations

Locations (1)

Centre de Soins Dentaires; 🇫🇷 Montpellier, France