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Skeletal Class III MalocclusionNCT07771660

Comparison of Ertty Gap III and Facemask Therapy for Skeletal Class III Correction

A study testing Ertty Gap III Appliance and Facemask Therapy in people with Skeletal Class III Malocclusion, run by Ankara University at 1 site in Turkey (Türkiye).

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This single-center, parallel-group randomized clinical trial compared 2 orthopedic treatment approaches in growing patients with skeletal Class III malocclusion associated predominantly with maxillary deficiency: the Ertty Gap III appliance and facemask therapy. Read more about this study

Who is it for?
Ages 9 to 12 years
Conditions the study is for
Skeletal Class III Malocclusion
What is being tested?
Ertty Gap III Appliance and Facemask Therapy
Could I receive a placebo?
No, everyone receives an active treatment
How many people
42 participants
Where
1 siteTurkey (Türkiye)
Study dates
25 May 2024to 9 Dec 2025
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 9 to 12 years
  • All sexes
  • No healthy volunteers
  • Child

Who may be able to join

  • Age between 9 and 12 years.
  • Late mixed or early permanent dentition.
  • Skeletal Class III malocclusion characterized by an A point-Nasion-B point (ANB) angle ≤ 0° and a Class III molar relationship.
  • Maxillary deficiency confirmed by clinical and cephalometric assessment, including evaluation of the Sella-Nasion-Point A (SNA) angle according to Steiner analysis (82° ± 2° as the reference) and clinical evidence of perinasal or midfacial deficiency.
  • In participants with associated mandibular prognathism, maxillary retrognathia was required to be the predominant skeletal component of the Class III discrepancy.
  • Anterior crossbite or an edge-to-edge incisal relationship.
  • No previous orthodontic or orthopedic treatment.

Who cannot join

  • Completed skeletal growth.
  • Skeletal Class III malocclusion attributable solely to mandibular prognathism without clinical or cephalometric evidence of maxillary retrognathia.
  • Presence of systemic disease.
  • Craniofacial syndromes or congenital craniofacial anomalies.
  • Temporomandibular joint disorders.
  • Congenital absence of maxillary lateral incisors.
  • Palatally displaced permanent canines.
  • Missing, extracted, or prematurely lost permanent first molars.

Trial locations and contacts

1 site in 1 country.

Turkey (Türkiye)1 site
  • Ankara University, Faculty of Dentistry, Department of Orthodontics

    Ankara, Ankara, 06560

Other trials in Turkey (Türkiye)

About this study

Official title: Targeting the Premaxillary-Maxillary Suture for Skeletal Class III Correction in Growing Patients: Ertty Gap III Versus Facemask Therapy in a Randomized Clinical Trial

This single-center, parallel-group randomized clinical trial compared 2 orthopedic treatment approaches in growing patients with skeletal Class III malocclusion associated predominantly with maxillary deficiency: the Ertty Gap III appliance and facemask therapy. Forty-two participants were randomly allocated in a 1:1 ratio to Ertty Gap III or facemask therapy. The primary objective was to compare the short-term skeletal effects of the 2 treatment protocols, with the ANB angle designated as the primary outcome. Skeletal, dentoalveolar, and soft-tissue outcomes were assessed using standardized lateral cephalometric radiographs obtained before treatment and at treatment completion.

Read the detailed description

Skeletal Class III malocclusion in growing patients may be associated with maxillary deficiency, mandibular prognathism, or a combination of both. Early orthopedic treatment directed toward maxillary advancement is commonly performed using facemask therapy. The Ertty Gap III appliance is an intraoral orthopedic appliance designed to apply Class III corrective forces through a different biomechanical configuration.

This prospective, single-center, parallel-group randomized clinical trial compared the short-term skeletal, dentoalveolar, and soft-tissue effects of the Ertty Gap III appliance with those of facemask therapy in growing patients with skeletal Class III malocclusion associated predominantly with maxillary deficiency. Forty-two eligible participants were randomly allocated in a 1:1 ratio to the Ertty Gap III or facemask group using concealed allocation.

Standardized lateral cephalometric radiographs were obtained before treatment (T0) and at completion of active orthopedic treatment (T1). The ANB angle was designated as the primary outcome. The between-treatment effect for ANB was evaluated by comparing posttreatment values between the groups after adjustment for the corresponding pretreatment value. Secondary and supportive exploratory outcomes included selected skeletal, dentoalveolar, occlusal, and soft-tissue cephalometric measurements.

Being tested
Ertty Gap III Appliance, Facemask Therapy
Keywords
Skeletal Class III Malocclusion, Maxillary Protraction, Ertty Gap III, Facemask Therapy, Premaxillary-Maxillary Suture, Orthopedic Treatment

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Ertty Gap III ApplianceDevice

    The Ertty Gap III appliance is an intraoral orthopedic appliance designed for maxillary protraction in growing patients with skeletal Class III malocclusion. The maxillary component consists of a sagittally oriented 90° inverted Hyrax expansion screw with an acrylic pad extending from the palatal rugae toward the premaxillary region and posterior occlusal build-ups. The mandibular component consists of a lip bumper-lingual arch assembly supported by the mandibular first permanent molars. Bilateral 5/16-inch, 8-ounce Class III intermaxillary elastics are applied between the maxillary first-molar region and the mandibular lip-bumper notches. The sagittal Hyrax screw is activated once weekly with two consecutive quarter-turns. Patients are instructed to wear the appliance and intermaxillary elastics full time, except during meals, oral hygiene, and contact sports. Patients are monitored at 4-week intervals.

  • Facemask TherapyDevice

    Conventional maxillary protraction was performed using a Petit-type facemask in combination with a 0.80-mm full-coverage vacuum-formed maxillary splint covering all maxillary teeth. Hooks were incorporated into the splint in the premolar region for attachment of bilateral protraction elastics. Maxillary expansion was not performed in order to isolate the effects of maxillary protraction. Bilateral protraction elastics delivered approximately 350 g of force per side, with the force vector directed approximately 30° downward from the occlusal plane. The applied force was verified using a force gauge at appliance delivery and at each follow-up visit. Participants were instructed to wear the facemask and elastics full time except during meals, oral hygiene, and contact sports. Follow-up visits were scheduled at 4-week intervals to assess appliance integrity, reinforce compliance, verify elastic force levels, and make necessary adjustments.

Study groups in NCT07771660
Study groupRoleWhat they receive
Ertty Gap III GroupExperimentalParticipants assigned to this arm received orthopedic treatment with the Ertty Gap III appliance. The treatment protocol involved maxillary protraction using an intraoral appliance designed to apply orthopedic forces to the maxillary complex. Treatment was continued until correction of the anterior crossbite and achievement of a positive overjet.
Receives: Device: Ertty Gap III Appliance
Facemask GroupActive comparatorParticipants assigned to this arm received conventional orthopedic maxillary protraction with facemask therapy. Treatment was continued until correction of the anterior crossbite and achievement of a positive overjet.
Receives: Device: Facemask Therapy

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in ANB Angle

    Change in the ANB angle (degrees) from baseline to completion of orthopedic treatment, assessed on standardized lateral cephalometric radiographs. The ANB angle represents the sagittal skeletal relationship between the maxilla and mandible. A positive change indicates improvement in the sagittal maxillomandibular relationship.

    Measured: Baseline to completion of orthopedic treatment (approximately 13 months; treatment continued until achievement of a positive overjet)

Secondary outcomes (9)
  1. Change in Sella-Nasion-Point A Angle (SNA)

    Change in the angle between the sella-nasion line and the nasion-point A line, measured in degrees on standardized lateral cephalometric radiographs.

    Measured: Baseline to completion of orthopedic treatment or the corresponding observation period (approximately 13 months)

  2. Change in Sella-Nasion-Point B Angle (SNB)

    Change in the angle between the sella-nasion line and the nasion-point B line, measured in degrees on standardized lateral cephalometric radiographs.

    Measured: Baseline to completion of orthopedic treatment or the corresponding observation period (approximately 13 months)

  3. Change in Gonion-Gnathion/Sella-Nasion Angle (GoGn/SN)

    Change in the angle between the gonion-gnathion plane and the sella-nasion plane, measured in degrees on standardized lateral cephalometric radiographs.

    Measured: Baseline to completion of orthopedic treatment or the corresponding observation period (approximately 13 months).

  4. Change in Maxillary Incisor-to-Palatal Plane Angle (U1-PP)

    Change in the angle between the long axis of the maxillary central incisor and the palatal plane, measured in degrees on standardized lateral cephalometric radiographs.

    Measured: Baseline to completion of orthopedic treatment or the corresponding observation period (approximately 13 months).

  5. Change in Incisor Mandibular Plane Angle (IMPA)

    Change in the angle between the long axis of the mandibular central incisor and the mandibular plane, measured in degrees on standardized lateral cephalometric radiographs.

    Measured: Baseline to completion of orthopedic treatment or the corresponding observation period (approximately 13 months).

  6. Change in Overjet

    Change in the horizontal distance between the maxillary and mandibular incisal edges, measured in millimeters on standardized lateral cephalometric radiographs.

    Measured: Baseline to completion of orthopedic treatment or the corresponding observation period (approximately 13 months).

  7. Change in Overbite

    Change in the vertical overlap of the maxillary and mandibular incisors, measured in millimeters on standardized lateral cephalometric radiographs.

    Measured: Baseline to completion of orthopedic treatment or the corresponding observation period (approximately 13 months).

  8. Change in Maxillary First Molar-to-Pterygoid Vertical Distance (U6d-PTV)

    Change in the horizontal distance from the distal surface of the maxillary first molar to the pterygoid vertical plane, measured in millimeters on standardized lateral cephalometric radiographs.

    Measured: Baseline to completion of orthopedic treatment or the corresponding observation period (approximately 13 months).

  9. Change in Nasolabial Angle

    Change in the angle formed by the columella-subnasale and subnasale-upper lip lines, measured in degrees on standardized lateral cephalometric radiographs.

    Measured: Baseline to completion of orthopedic treatment or the corresponding observation period (approximately 13 months).

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted18 Aug 2026
  2. Study start25 May 2024
  3. Primary completion9 Dec 2025
  4. Study completion9 Dec 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Forty-two participants were randomly allocated in a 1:1 ratio to either Ertty Gap III therapy or facemask therapy using a parallel-group design. Participants remained in their assigned treatment group throughout the study.
Masking
None (open label)
Enrolment
42 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07771660
Sponsor's protocol ID
ERTTY-FM-CLASSIII-02
Status last verified
Sep 2026
First submitted
11 Aug 2026
Last updated
15 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: Individual participant data will not be publicly shared. The informed consent permits the use of clinical records for research, educational purposes, and scientific publications; however, it does not specifically provide for sharing individual-level participant data with other researchers or through public data repositories.

Publications

  • de Souza RA, Rino Neto J, de Paiva JB. Maxillary protraction with rapid maxillary expansion and facemask versus skeletal anchorage with mini-implants in class III patients: a non-randomized clinical trial. Prog Orthod. 2019 Sep 2;20(1):35. doi: 10.1186/s40510-019-0288-7.

    PubMed 31475309
  • Foersch M, Jacobs C, Wriedt S, Hechtner M, Wehrbein H. Effectiveness of maxillary protraction using facemask with or without maxillary expansion: a systematic review and meta-analysis. Clin Oral Investig. 2015 Jul;19(6):1181-92. doi: 10.1007/s00784-015-1478-4. Epub 2015 May 19.

    PubMed 25982454

Questions about this trial

What is this clinical trial studying?

A study testing Ertty Gap III Appliance and Facemask Therapy in people with Skeletal Class III Malocclusion, run by Ankara University at 1 site in Turkey (Türkiye).

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 15 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in ANB Angle (time frame: Baseline to completion of orthopedic treatment (approximately 13 months; treatment continued until achievement of a positive overjet)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07771660, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Sep 2026.

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