Quad Helix and Correction of Mandibular Asymmetry

Is the Quad Helix More Efficient to Correct Mandibular Asymmetry Before Age 7? A Retrospective Comparative Study

To compare the effectiveness of the Quad Helix, an orthopaedic conventional appliance, in the correction of skeletal mandibular asymmetry, on frontal x-ray, in subjects treated before or after 7 years.

Study Overview

• Status: Completed
• Conditions: Mandibular Asymmetry; Functional Shift of the Mandible
• Intervention / Treatment: Device: Maxillary expansion with conventional Quad Helix bonded on molars.

Detailed Description

Introduction : Unilateral posterior crossbite (UPCB), often from dysfunctional and para-functional causes, leads to positional mandibular asymmetries that can develop at a very young age into skeletal mandibular deviation; hence the interest of early maxillary expansion. The purpose of this retrospective study was to compare the impact of maxillary expansion by Quad Helix (QH) on mandibular skeletal asymmetry correction before and after 7 years of age.

Materials and methods : All children with UPCB and skeletal mandibular asymmetry, who were treated by QH in the orthodontic department between February 2017 and August 2018 and who have done a radiography file at baseline (T0) and 12 months later (T1) have been included. The patients were divided into two groups according to age: under 7 years of age (early group G1) with QH adjusted on second primary molars and over up to 13 years old (late group G2) with QH adjusted on first permanent molars. The differences between the right and left sides of the mandible in corpus length L (main eligibility criterion) and ramus height H (secondary criterion) were compared between groups. X² test, Fisher's exact test and Wilcoxon rank-sum tests were used for baseline comparisons. A multifactorial analysis allowing adjustment on possible confounding factors was used with R software at a significance level of 5%.

• Study Type: Observational
• Enrollment (Actual): 67

Contacts and Locations

Study Locations

• France
  • Montpellier, France, 34295
    • UHMontpellier

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 4 years to 13 years (Child)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients of Orthodontic Department of the CHU of Montpellier

Description

Inclusion criteria:

• Unilateral Posterior Crossbite (at least one tooth) and skeletal mandibular asymmetry
• Treated by Quad Helix in the Orthodontic Department of the CHU Montpellier
• with frontal X-rays available at baseline and 12months later

Exclusion criteria:

• Incomplete File
• Inadequate quality of x-rays

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
G1 or Early Group; Patients treated before age 7 (Quad Helix on decidual second molars)	Device: Maxillary expansion with conventional Quad Helix bonded on molars.; Maxillary expansion with conventional Quad Helix bonded on molars
G2 or Late Group; Patients treated between 7 and 13 years old (Quad Helix on first permanent molars)	Device: Maxillary expansion with conventional Quad Helix bonded on molars.; Maxillary expansion with conventional Quad Helix bonded on molars

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in the mandibular corpus length between the right and left side	Difference in the mandibular corpus length between the right and left side : △L on conventional frontal x-ray.	1 day

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in the mandibular ramus height between the right and left side of the mandibule	Difference in the mandibular ramus height between the right and left side of the mandibule : △H on conventional frontal x-ray.	1 day

Collaborators and Investigators

• Sponsor: University Hospital, Montpellier
• Investigators: Principal Investigator: Manon Fourneron, University Hospital, Montpellier

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2017
• Primary Completion (Actual): August 1, 2019
• Study Completion (Actual): August 30, 2019

Study Registration Dates

• First Submitted: June 9, 2020
• First Submitted That Met QC Criteria: June 9, 2020
• First Posted (Actual): June 12, 2020

Study Record Updates

• Last Update Posted (Actual): June 12, 2020
• Last Update Submitted That Met QC Criteria: June 9, 2020
• Last Verified: June 1, 2020

More Information

Terms related to this study

• Keywords: Early treatment; Posterior unilateral cross bite; Quad helix
• Other Study ID Numbers: RECHMPL20_0350

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: NC

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No