Efficacy of RME and Facemask Therapy for Class III Malocclusion

NCT07053683 | Completed

• 1 other identifier: WHH-ORTHO-2018-021
• Study Type: interventional
• Target: 358
• Locations: 1 country
• Sites: 1

Brief Summary

This multicenter randomized controlled trial compares the efficacy of Rapid Maxillary Expansion (RME) combined with facemask (FM) protraction versus FM protraction alone in treating growing children with skeletal Class III malocclusion. The study aims to evaluate the differences in vertical skeletal changes and Oral Health-Related Quality of Life (OHRQoL) between the two treatments.

Conditions

Skeletal Class III Malocclusion

Keywords

Palatal Expansion Technique; Extraoral Traction Appliances; Malocclusion; Angle Class III; Cephalometry; Rapid Maxillary Expansion; Oral Health-Related Quality of Life

Outcome Measures

Primary Outcomes (2)

• Change in Vertical Linear Cephalometric Measurements

  Measured from standardized lateral cephalograms and Cone-Beam Computed Tomography (CBCT) scans. Key measurements include overbite (mm), maxillary molar vertical position (PP-Ms distance, mm), and maxillary anterior position (X-A distance, mm).

  Baseline, 12 Months

• Change in Angular Cephalometric Measurements

  Measured from standardized lateral cephalograms and CBCT scans. Key measurements include sagittal jaw relationship (ANB angle, degrees), mandibular plane angle (SN-MP, degrees), and palatal plane angle (SN-PP, degrees).

  Baseline, 12 Months

Secondary Outcomes (2)

• Change in Dental Positional Measurements

  Baseline (T0) and 6-month follow-up (T1).

• Change in Dental Cephalometric Measurements

  Baseline, 12 Months

Study Arms (2)

Experimental: RME+FM Group

EXPERIMENTAL

Patients received a tooth-borne Hyrax-type rapid maxillary expander. After the active expansion phase, a Petit-type facemask was delivered, applying a forward and downward protraction force of 400-500g per side for 12-14 hours per day.

Device: Combined RME and Facemask Therapy

Control: Facemask (FM) Alone Group

ACTIVE COMPARATOR

Patients received the same facemask protraction therapy as the experimental group (same force, direction, and duration) but without undergoing RME. A removable mandibular occlusal splint was provided to disarticulate the occlusion.

Device: Facemask Therapy Alone

Interventions

Combined RME and Facemask Therapy DEVICE

This intervention involves two components. First, a tooth-borne Hyrax-type rapid maxillary expander is banded to the maxillary first permanent and deciduous molars. The screw is activated twice daily until posterior crossbite is overcorrected. Second, immediately following expansion, a Petit-type facemask is used to apply orthopedic protraction forces to the maxilla.

Experimental: RME+FM Group

Facemask Therapy Alone DEVICE

This intervention involves the use of a Petit-type facemask to apply orthopedic protraction forces (400-500g per side, 12-14 hours/day) to the maxilla. A removable mandibular occlusal splint (flat bite plane) is used concurrently to facilitate anterior crossbite correction.

Control: Facemask (FM) Alone Group

Eligibility Criteria

• Age: 7 Years - 12 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Skeletal Class III malocclusion (ANB angle ≤ 0°) with a Wits appraisal ≤ -2 mm.
• Maxillary deficiency (SNA angle ≤ 80°).
• Prepubertal stage of skeletal development (Cervical Vertebral Maturation Stage CS1-CS3).
• Age between 7 and 12 years.
• Anterior crossbite or edge-to-edge incisor relationship.
• Angle Class III or end-on molar relationship.
• No previous orthodontic treatment.

You may not qualify if:

• Functional Class III malocclusion with no centric relation-centric occlusion discrepancy.
• Congenital craniofacial anomalies (e.g., cleft lip/palate).
• Severe systemic diseases.
• History of maxillofacial trauma.

Sponsors & Collaborators

• Wuhan Integrated Traditional Chinese and Western Medicine Hospital: lead

Study Sites (1)

Wuhan No.1 Hospital

Wuhan, Hubei, 430000, China

Location

MeSH Terms

Conditions

Malocclusion; Malocclusion, Angle Class III

Condition Hierarchy (Ancestors)

Tooth Diseases; Stomatognathic Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal investigator

Study Record Dates

• First Submitted: June 27, 2025
• First Posted: July 8, 2025
• Study Start: January 1, 2019
• Primary Completion: December 31, 2023
• Study Completion: December 31, 2023
• Last Updated: August 22, 2025

Record last verified: 2025-06

Locations

CN (1)