Condition category
Oral Health
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
Not yet recruiting

Plain English Summary

Background and study aims
Malocclusion means that the upper and lower teeth do not fit together well. This can cause problems with chewing and dental hygiene. Class II malocclusion (overjet) is where the upper jaw teeth are further forward than the lower jaw teeth. This is commonly caused by the lower jaw being underdeveloped or being positioned too far back. Class II malocclusion can be treated in growing children by wearing braces that encourage the lower jaw to grow or move forward. This study aims to compare three braces to eachother and to no treatment in correcting class II malocclusion in children before and during puberty.

Who can participate?
Children aged 17 years or under who need orthodontic treatment for class II malocclusion.

What does the study involve?
Participants who choose to delay wearing a brace will have X-rays at the start of the study and at 18 months. Those who choose to start treatment immediately will be randomly allocated to wear one of three braces. They will have X-rays at the start of the study and at the end of treatment.

What are the possible benefits and risks of participating?
Participants will benefit from correction of their malocclusion. There are no risks expected for those taking part in the study. The braces might be uncomfortable at the start.

Where is the study run from?
University of Turin Dental School (Italy)

When is the study starting and how long is it expected to run for?
June 2019 to December 2023

Who is funding the study?
University of Turin (Italy)

Who is the main contact?
Professor Tommaso Castroflorio,

Trial website

Contact information



Primary contact

Prof Tommaso Castroflorio


Contact details

Dental School
Department of Surgical Sciences
Orthodontics Division
University of Turin
Via Nizza 230
+39 0116331547



Additional contact

Dr Serena Ravera


Contact details

Dental School
Department of Surgical Sciences
Orthodontics Division
University of Turin
Via Nizza 230
+39 0116331547

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number


Study information

Scientific title

Dento-skeletal effects of removable functional appliances in class II growing patients: a randomized controlled trial



Study hypothesis

The aim of this study is to compare dento-skeletal effects of functional removable appliances in skeletal Class II malocclusion in growing patients at different stages of growth, according to cervical vertebral maturation method (CVM2 and CVM3), compared to untreated subjects.

Ethics approval

Approved 21/02/2020, Ethics Board of the City of Health And Science of Turin [Comitato Etico Interaziendale A.O.U. Città della Salute e della Scienza di Torino] (Corso Bramante 88/90, 10126 Turin, Italy; +39 011 6331633; ), ref: 000127/2019

Study design

Single-centre randomized controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

See additional files for a participant information sheet in Italian.




In this randomized controlled trial, the sample will be composed of 4 arms: no treatment (patients that autonomously choose to delay the treatment), and 3 randomly assigned treatment arms (EF myofunctional device, Invisalign with mandibular advancement feature, Function Generating Bite arm) comprising 15 Caucasian growing class II subjects for each arm. The randomization will be generated using Randomizer software.

Within the group treated, there will be two subgroups according to the cervical vertebrae maturation (CVM) stage of growth at the beginning of treatment (T0): 8 patients at CVM2 stage of growth (pre-pubertal) and 8 patients at CVM3 stage of growth (pubertal). The same criteria will be adopted for the control group.

The average duration of treatment will be 18 months. The participants will use the devices until the malocclusion is corrected. All the devices are removable, i.e. they can be taken out of the mouth.

Cephalometric analysis
For each patient included in the study, lateral radiographs will be collected both at the beginning (T0) and at the end of the treatment (T1). If the X-rays will be performed with different machines, it will be necessary to calibrate the images before starting the cephalometric tracings.
An orthodontic software (Dolphin Imaging & Management Solutions, at Patterson Technology, Verona, Italy) will be used to standardize the X-rays and perform the cephalometric tracings at T0 and T1.
From a skeletal point of view the cephalometric values analyzed will be: SN^GoGn, SpP^GoGn, SNA, SNB, ANB, A Downs, B Downs, A:Po, Wits Index, ArGo^Gn together with the linear mandibular measurement Go:Co, Gn:Co, Gn:Go.
From the dental point of view the attention will be focused on the incisor sector level and therefore 11^SpP, 41^GoGn and 11^41.

Intervention type



Not Applicable

Drug names

1. FGB (Function Generating Bite)
2. Invisalign® Mandibular Advancement Feature (MAF; Align Technology, Santa Clara, CA, USA)
3. EF Educatore Funzionale (OrthoPlus, Igny, France)

Primary outcome measure

1. SN^GoGn
2. SpP^GoGn
3. SNA
4. SNB
5. ANB
6. A Downs
7. B Downs
8. A:Po
9. Wits Index
10. ArGo^Gn
11. Go:Co
12. Gn:Co
13. Gn:Go
14. 11^SpP
15. 41^GoGn
16. 11^41

All parameters will be calculated by analysing lateral radiographs taken before treatment and at the end of treatment.

Secondary outcome measures

Puberty stage of participant

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Divergence between cranial base and mandibular plane within normal limits (SN^GoGn <37°)
2. Moderate crowding in the upper arch (≤4 mm)
3. Good patient compliance (18-22 h per day)
4. Excellent radiographic record quality, with adequate cephalometric point display and head rotation control
5. Aged 8-17 years

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Severe transverse dental or skeletal discrepancies
2. Severe vertical dental or skeletal discrepancies
3. Extraction treatments
4. Temporomandibular disorders (TMDs)
5. Periodontal disease

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

University of Turin Dental School
Via Nizza 230

Sponsor information


University of Turin

Sponsor details

Via Nizza 230
+39 01163354

Sponsor type




Funder type


Funder name

Università degli Studi di Torino

Alternative name(s)

University of Turin, UNITO

Funding Body Type

government organisation

Funding Body Subtype

government non-federal



Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer reviewed journals in 2024.

IPD sharing statement:
The datasets generated and/or analysed during this study will be included in the subsequent results publication

Intention to publish date


Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

30/04/2020: The participant information sheet was uploaded as an additional file. 19/03/2020: Trial's existence confirmed by Comitato Etico Interaziendale A.O.U. Città della Salute e della Scienza di Torino.