The Effectiveness of the Twin Block and Carriere Motion Appliances in Post-pubertal Patients and an Evaluation of the Impact of Class II Malocclusion and Its Correction on Oral Health-related Quality of Life

NCT07292636 | Not Yet Recruiting

• 1 other identifier: 250901
• Study Type: interventional
• Target: 88
• Locations: 1 country
• Sites: 1

Brief Summary

The investigators of this clinical trial aim to:

• Compare the effectiveness and efficiency of Clark's Twin Block Appliance (CTB) vs Carriere Motion Appliance (CMA) in correcting Class II malocclusion when used in post-pubertal older adolescents, in terms of skeletal and dental change.
• Evaluate potential negative oral health-related quality of life (OHRQoL) impacts during the active treatment phase with either CTB or CMA in post-pubertal adolescents.
• Investigate the impact of Class II malocclusion on oral health-related quality of life (OHRQoL) in post-pubertal adolescents. Class II division 1 malocclusion is a dental condition where the upper teeth protrude significantly over the lower teeth. It is a common type of malocclusion observed in orthodontic practice, accounting for approximately 20-25% globally. Correcting Class II malocclusion in growing patients using functional appliances and Class II correctors is relatively predictable. In Ireland and the United Kingdom, the Clark's Twin Block (CTB) is the most commonly used functional appliance. The CTB consists of two components: one for the upper teeth and one for the lower teeth. These components are engineered to position the lower jaw forward, thereby promoting the desired dentoskeletal changes (moving the upper teeth back and lower forward). Another device used for Class II correction is the Carriere Motion Appliance (CMA). The CMA is gaining popularity as a treatment option for Class II malocclusion, inducing dental changes similar to those achieved with a CTB. However, uncertainty persists regarding the effectiveness of these appliances in older adolescents in the post-pubertal growth phase (aged approximately 14.5 years or above). Additionally, although both CTB and CMA are effective in growing patients in correcting dental and skeletal discrepancies, they may influence daily activities, comfort, and psychological aspects, which often results in poor compliance. Poor adherence to orthodontic treatment, whether with fixed or removable appliances, can lead to higher rates of treatment failure.

Conditions

Growth; CLASS II DIVISION 1 MALOCCLUSION; Class II Malocclusion; Overjet; Class II Buccal Segment Relationship; Class II Growth Modification; Distalization; Oral Health-Related Quality of Life

Keywords

Class II Malocclusion; Overjet; Class II Molar Relationship; Class II Canine Relationship; Functional Appliance; Class II Corrector; Growth Modification; Oral Health Related Quality of Life; Twin Block; Carriere Motion Appliance; RCT

Outcome Measures

Primary Outcomes (1)

• Change in molar and canine relationship at T3 (effectiveness)

  The primary outcome measure (change in molar and canine relationship) will be calculated at T3. This will be calculated by measuring the difference from T0 to T3 in the horizontal plane (in mm); * from the cusp tip of maxillary canine relative to the distal contact point of the opposing mandibular canine (change in canine relationship) and * from the mesiobuccal cusp of maxillary first molar relative to the buccal groove of mandibular first molar (change in molar relationship). All the measurements will be performed on dental study casts (taken at T0 and T3) articulated in maximum intercuspation position (MIP) using a vernier calliper. Measurements from right and left sides will be taken. Change in the canine and molar relationship will be calculated as the difference from T0 to T3.

  T3: 9 months

Secondary Outcomes (5)

• Change in molar and canine relationship at T2 (efficiency)

  T2: 18 weeks

• Dentoskeletal cephalometric changes at T3

  T3: 9 months

• Impact of treatment on daily life based on the Orthodontic Treatment Impact Questionnaire (OTIQ) scores at T1 and T3

  T1: 2 weeks; T3: 9 months

• Impact of Class II correction on oral health-related quality of life (OHRQoL) based on the Malocclusion Impact Questionnaire (MIQ) scores at T0 and T4

  T0: Baseline; T4: 42 weeks

• Impact of Class II correction on oral health-related quality of life (OHRQoL) based on the Child Oral Health Impact Profile (COHIP-19) scores at T0 and T4

  T0: Baseline; T4: 42 weeks

Study Arms (2)

CTB group

ACTIVE COMPARATOR

Participants assigned to this group will receive CTB.

Device: CTB

CMA group

EXPERIMENTAL

Participants assigned to this group will receive CMA.

Device: CMA

Interventions

CTB DEVICE

The appliance will be used with the bite registration taken in maximum protrusion incorporating the following features: (1) Adam's clasps on all first premolars and first permanent molars, (2) three ball-ended clasps on the mandibular incisors, (3) midline expansion screw in the maxillary component, (4) blocks intersecting at 70 degrees, with a height of 5-6 mm in the premolar region. Patients will be instructed to wear the appliance full-time, except for eating, and during contact or water sports. Objective wear time in minutes will be recorded by a Theramon® microsensor (Handelsagentur Gschladt, Hargelsberg, Austria, or Forestadent, Pforzheim, Germany) placed in the maxillary component.

CTB group

CMA DEVICE

The appliance consists of rigid stainless-steel or acrylic bars bonded to the maxillary canines and first molars bilaterally. Elastics will be worn in a Class II pattern, from hooks on the maxillary canine to attachments on the mandibular first molar (bonded molar tubes). Anchorage in the mandibular dentition will be provided by an Essix-type retainer. Patients will be instructed to wear elastics full time except for eating and cleaning the teeth. The elastics protocol for the CMA appliance will be: Force 1 elastics (Henry Schein Orthodontics) that generate about 375 g of force that will be used during the first 6 weeks, changed to Force 2 elastics that generate about 540 g of force thereafter.

CMA group

Eligibility Criteria

• Age: 14 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• males and females aged 14 ½ -16 years from the HSE waiting list,
• Cervical Vertebral Maturation (CVM) stage ≥5,
• a mild-moderate skeletal II pattern,
• normodivergent with average maxillomandibular planes angle (MMPA: 27±4 degrees),
• Class II division 1 incisor relationship,
• Class II molar relationship of ≥1/2 unit bilaterally,
• overjet of ≥7 mm,
• ≤5mm of dental crowding in both arches and
• fluent English speaker.

You may not qualify if:

• high MMPA,
• low MMPA,
• have/had cleft lip or palate or craniofacial syndrome,
• hypodontia,
• gross mandibular asymmetry,
• a medically diagnosed growth excess or deficiency,
• not dentally fit or
• had previously received orthodontic treatment.

Sponsors & Collaborators

• Dublin Dental University Hospital: collaborator
• Aslam Alkadhimi: lead
• Health Service Executive, Ireland: collaborator
• University of Dublin, Trinity College: collaborator

Study Sites (1)

Ashtown Gate HSE Orthodontic Unit

Dublin, Dublin, D 15, Ireland

Location

MeSH Terms

Conditions

Malocclusion, Angle Class II; Overbite

Condition Hierarchy (Ancestors)

Malocclusion; Tooth Diseases; Stomatognathic Diseases

Study Officials

• Prof Padhraig Fleming

  Chair/Professor of Orthodontics. Programme Lead, Doctorate in Orthodontics. Division of Public and Child Dental Health. Dublin Dental University Hospital.

  STUDY CHAIR

• Aslam Alkadhimi

  Dublin Dental Hospital, Trinity College Dublin

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Prof Padhraig Fleming

CONTACT

0035316127252; padhraig.fleming@dental.tcd.ie

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Blinding of either patient or clinician will not be possible due to the nature of intervention. The trial will be single-blind, blinding will be ensured at the data collection and analysis stages in which the researchers (investigators) and statistician (outcome assessor) will be blinded to the intervention by coding all dental study casts and lateral cephalograms. The final dental study casts, lateral cephalograms and photographs will be taken (at T3) after removal of CMA and CTB so the researchers do not know which group the patients were in.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: PhD researcher/Consultant Orthodontist

Model Details: Trial design: Two-arm, parallel group. Conceptual framework: Superiority trial. Allocation ration: A 1:1 allocation ratio.

Study Record Dates

• First Submitted: December 3, 2025
• First Posted: December 18, 2025
• Study Start: March 1, 2026
• Primary Completion (Estimated): September 1, 2027
• Study Completion (Estimated): September 1, 2029
• Last Updated: December 18, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP
• Time Frame: After trial completion.
• Access Criteria: Journal editors upon request.

Locations

IE (1)