Efficacy of RME and Facemask Therapy for Class III Malocclusion

NCT ID: NCT07053683

Last Updated: 2025-08-22

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 358 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-01-01
• Study Completion Date: 2023-12-31

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.

Detailed Description

Skeletal Class III malocclusion is a challenging craniofacial anomaly, particularly prevalent in Asian populations. Early orthopedic intervention aims to correct the discrepancy and guide favorable growth. While facemask (FM) protraction is a standard treatment, its efficacy can be enhanced by Rapid Maxillary Expansion (RME), which is thought to disarticulate the circummaxillary sutures and facilitate a better orthopedic response. This prospective, multicenter, randomized controlled trial was designed to rigorously compare the combined RME+FM therapy against FM therapy alone. The study's primary objective was to assess the impact of these interventions on vertical skeletal dimensions, a key concern in Class III treatment. The secondary objective was to evaluate the patient-centered outcome of Oral Health-Related Quality of Life (OHRQoL). Eligible patients aged 7-12 were randomly assigned to one of two treatment groups. Cephalometric and OHRQoL data were collected at baseline and after 12 months of active treatment to determine if the combined approach offers superior clinical outcomes.

Conditions

Skeletal Class III Malocclusion

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Experimental: RME+FM Group

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.

Group Type: EXPERIMENTAL

Combined RME and Facemask Therapy

Intervention Type: 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.

Control: Facemask (FM) Alone Group

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.

Group Type: ACTIVE_COMPARATOR

Facemask Therapy Alone

Intervention Type: 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.

Interventions

Combined RME and Facemask Therapy

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.

Intervention Type: DEVICE

Facemask Therapy Alone

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.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• 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.

Exclusion Criteria

• 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.

• Minimum Eligible Age: 7 Years
• Maximum Eligible Age: 12 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Wuhan Integrated Traditional Chinese and Western Medicine Hospital

OTHER

Sponsor Role: lead

Responsible Party

Lulu Wang

Principal investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Wuhan No.1 Hospital

Wuhan, Hubei, China

Countries

China

Other Identifiers

WHH-ORTHO-2018-021

Identifier Type: -

Identifier Source: org_study_id