Efficacy of RME and Facemask Therapy for Class III Malocclusion

Wuhan Integrated Traditional Chinese and Western Medicine Hospital

Status: Completed

Conditions: Skeletal Class III Malocclusion

Treatments: Device: Combined RME and Facemask Therapy; Device: Facemask Therapy Alone

Study type: Interventional

Funder types: Other

Identifiers

NCT07053683

WHH-ORTHO-2018-021

Details and patient eligibility

About

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.

Full 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.

Enrollment: 358 patients

Sex: All

Ages: 7 to 12 years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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358 participants in 2 patient groups

Experimental: RME+FM Group

Experimental group

Description:

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.

Treatment:

Device: Combined RME and Facemask Therapy

Control: Facemask (FM) Alone Group

Active Comparator group

Description:

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.

Treatment:

Device: Facemask Therapy Alone