Effects of Invisalign Palatal Expander vs Rapid Palatal Expander With Facemask in Growing Class III Patients

NCT07485478 | Not Yet Recruiting FDA Device

• 1 other identifier: MU-DT/PY-IRB 2025/095.2312
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to compare two types of palatal expanders used with a facemask in children who have skeletal Class III and a narrow upper jaw. The study will compare the Invisalign Palatal Expander (IPE) and the Rapid Palatal Expander (RPE). Researchers want to learn how these devices affect jaw bones and tooth position. They also want to learn about children's and parents' experiences during treatment. The main questions this study aims to answer are: Do IPE and RPE widen the upper jaw differently? Do they cause different changes in tooth position? How do children and parents describe their treatment experience? Participants will be children aged 8 to 12 years who have skeletal Class III and a narrow upper jaw. Children with craniofacial conditions, previous upper jaw expansion, or medical conditions that prevent orthodontic treatment will not take part. Parents and children must give consent before joining the study. Participants will: Be assigned to receive either IPE or RPE Expand the upper jaw to 7 mm (0.25 mm per day) After expansion, wear a facemask for at least 12 hours per day for 6 to 8 months Have cone-beam computed tomography (CBCT) scans taken before expansion, after expansion, and after facemask treatment Take part in an interview with a parent after expansion Researchers will use CBCT images to measure changes in jaw bones and tooth position. The main outcomes are changes in jaw bones and tooth position. Secondary outcomes include children's and parents' experiences during treatment.

Conditions

Transverse Maxillary Deficiency; Skeletal Class III Malocclusion

Keywords

Invisalign Palatal Expander; Rapid Palatal Expansion; Facemask; CBCT; Retrognathic maxilla

Outcome Measures

Primary Outcomes (2)

• Maxillary skeletal change

  * Anterior and posterior midpalatal suture width * Anterior apical base width inferior * Anterior apical base width superior * Posterior apical base width * Anterior width at mid-alveolar level * Posterior width at alveolar crest level

  T0: Baseline (Day 0) - before initiation of maxillary expansion T1: Post-expansion - after completion of 7 mm expansion with RPE or IPE T2: Post-protraction - after 6 months of active maxillary protraction

• Maxillary dental change

  * Intermolar width at occlusal surface * Intermolar width at palatal root apices * Right first molar angulation * Left first molar angulation

  T0: Baseline (Day 0) - before initiation of maxillary expansion T1: Post-expansion - after completion of 7 mm expansion with RPE or IPE T2: Post-protraction - after 6 months of active maxillary protraction

Secondary Outcomes (1)

• Functional and perceptual experiences and parental involvement associated with the use of Rapid Palatal Expander (RPE) and Invisalign Palatal Expander (IPE).

  Single assessment at 28 days (± 5 days) after appliance insertion

Study Arms (2)

Invisalign Palatal Expander (IPE) group

EXPERIMENTAL

Device: Invisalign Palatal Expander (IPE)

Rapid Palatal Expander (RPE) group

ACTIVE COMPARATOR

Device: Rapid Palatal Expander (RPE)

Interventions

Invisalign Palatal Expander (IPE) DEVICE

Participants will be treated with an Invisalign palatal expander. Participants will be instructed to wear the appliance full-time, except when brushing and flossing their teeth, and to change the device daily (0.25 mm) until the planned transverse width (7 mm.) is achieved.

Invisalign Palatal Expander (IPE) group

Rapid Palatal Expander (RPE) DEVICE

Participants will be treated with a bonded RPE. Their parents are instructed to activate the screw once per day (0.25 mm) until the expansion screw reaches 7 mm.

Rapid Palatal Expander (RPE) group

Eligibility Criteria

• Age: 8 Years - 12 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Patients aged between 8 and 12 years
• Patients in the mixed dentition or early permanent stage have at least three stable teeth per quadrant, good oral hygiene, and healthy periodontal tissues
• Patients with maxilla-mandibular discrepancies; skeletal class III is indicated by an ANB angle \< 0 degrees or a Wits appraisal value that is negative, and Maxillary constriction is characterized by posterior crossbite teeth or having a maxillary width below the norm value.

You may not qualify if:

• Patients with craniofacial anomalies such as cleft lip and palate
• Patient with a prior history of maxillary expansion.
• Patients who have systemic conditions that contraindicate orthodontic treatment.

Sponsors & Collaborators

• Mahidol University: lead

Study Sites (1)

Faculty of Dentistry, Mahidol University

Bangkok, 10700, Thailand

Location

Related Publications (1)

• Weissheimer A, de Menezes LM, Mezomo M, Dias DM, de Lima EM, Rizzatto SM. Immediate effects of rapid maxillary expansion with Haas-type and hyrax-type expanders: a randomized clinical trial. Am J Orthod Dentofacial Orthop. 2011 Sep;140(3):366-76. doi: 10.1016/j.ajodo.2010.07.025.

  PMID: 21889081 BACKGROUND

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: SPONSOR

Study Record Dates

• First Submitted: March 2, 2026
• First Posted: March 20, 2026
• Study Start: March 1, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): October 1, 2027
• Last Updated: March 20, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

TH (1)