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OpenTrials
Active, Not Recruiting

NCT Number: NCT04911400

Effects of Class III Elastics on Stability of Orthopaedic Class III Correction

The purpose of this study is to evaluate the effects of adding elastics to orthodontic retainers on the stability of class III correction and whether it reduces the need for jaw surgery.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Class III Malocclusion Malocclusion Malocclusion, Angle Class III Stomatognathic Diseases Tooth Diseases Underbite

Age range

12 year–16 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Chatswood Orthodontics, Chatswood, New South Wales, Australia

Loading trial locations.

About this study

Over the years many types of appliances have been recommended for retaining Class III correction in growing children such as intermaxillary splints, class III activator, Frankel 3, Class III twin block, continued use of face-mask and chin-cup. However, currently none of these are in routine use and there is no evidence on the long term effectiveness of any retention protocol for class III correction.

One of the most commonly used retainers following orthodontic treatment is clear plastic retainers. There are no studies that investigated whether using class III elastics in combination with clear plastic retainers improves the stability of class III correction and reduces the need for later jaw surgery.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients that completed their orthodontic treatment for the management of their skeletal class III with upper jaw retrusion that was treated with Class III orthopaedic appliances, followed by full fixed appliances.
  • No congenital anomalies or craniofacial syndromes
  • No other orthodontic treatment
  • No medical history that effects growth

Exclusion criteria

  • Congenital anomalies or craniofacial syndromes
  • Other orthodontic treatment
  • Medical history that effects growth

Treatment and study plan

Upper-lower clear plastic retainers + Class III elastics

Other

Addition of Class III elastics to clear plastic retainers

Upper-lower clear plastic retainers

Other

Upper-lower clear plastic retainers

Primary outcomes

  1. Difference in overjet of participants in the 2 study arms

    Time frame: 5 years

    Measurement of overjet

Secondary outcomes

  1. Need for jaw surgery

    Time frame: 5 years

    Need for surgery assessed by a panel of orthodontists

  2. Difference in upper jaw position

    Time frame: 5 years

    The difference in SNA angle measured on cephalometric radiographs between groups

  3. Difference in lower jaw position

    Time frame: 5 years

    The difference in SNB angle measured on cephalometric radiographs between groups

  4. Difference in upper-lower jaw relationship

    Time frame: 5 years

    The difference in ANB angle measured on cephalometric radiographs between groups

  5. Difference in upper incisor angulation

    Time frame: 5 years

    The difference in upper incisor angle measured on cephalometric radiographs between groups

  6. Difference in lower incisor angulation

    Time frame: 5 years

    The difference in lower incisor angle measured on cephalometric radiographs between groups

  7. Compliance and ease of use of both retention regimens

    Time frame: 5 years

    Questionnaire on the frequency and ease of use of both retainer regimens will be used

  8. Effect of elastics on alignment retention

    Time frame: 5 years

    Little's irregularity index will be used to compare both groups

  9. Periodontal health, including recession around the incisors

    Time frame: 5 years

    Presence of gingival recession and prominence of lower incisors will be evaluated for both groups

Sponsors and collaborators

Lead sponsor

Sydney Local Health District

Other Gov

Registry information

Important dates

Study start
2020
Primary completion
2027
Study completion
2027
First posted
Jun 3, 2021
Registry last updated
May 8, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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