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

Not Applicable
Conditions
Class III Malocclusion
Underbite
Interventions
Other: Upper-lower clear plastic retainers + Class III elastics
Other: Upper-lower clear plastic retainers
Registration Number
NCT04911400
Lead Sponsor
Sydney Local Health District
Brief Summary

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.

Detailed Description

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.

Recruitment & Eligibility

Status
ENROLLING_BY_INVITATION
Sex
All
Target Recruitment
42
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

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Upper-lower clear plastic retainers + Class III elasticsUpper-lower clear plastic retainers + Class III elasticsUpper-lower clear plastic retainers + Class III elastics
Upper-lower clear plastic retainersUpper-lower clear plastic retainersUpper-lower clear plastic retainers
Primary Outcome Measures
NameTimeMethod
Difference in overjet of participants in the 2 study arms5 years

Measurement of overjet

Secondary Outcome Measures
NameTimeMethod
Difference in upper jaw position5 years

The difference in SNA angle measured on cephalometric radiographs between groups

Difference in upper-lower jaw relationship5 years

The difference in ANB angle measured on cephalometric radiographs between groups

Difference in upper incisor angulation5 years

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

Periodontal health, including recession around the incisors5 years

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

Need for jaw surgery5 years

Need for surgery assessed by a panel of orthodontists

Difference in lower jaw position5 years

The difference in SNB angle measured on cephalometric radiographs between groups

Difference in lower incisor angulation5 years

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

Compliance and ease of use of both retention regimens5 years

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

Effect of elastics on alignment retention5 years

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

Trial Locations

Locations (2)

Sydney Dental Hospital

🇦🇺

Surry Hills, New South Wales, Australia

Chatswood Orthodontics

🇦🇺

Chatswood, New South Wales, Australia

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