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Treatment of Class III Malocclusion Using Modified Fixed Mandibular Retractor Appliance

Evaluation of the Efficacy of Modified Fixed Mandibular Retractor Appliance in the Treatment of Class III Malocclusion: A Clinical Randomized Controlled Trial

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03354442
Enrollment
44
Registered
2017-11-28
Start date
2017-05-15
Completion date
2019-01-10
Last updated
2019-07-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Malocclusion, Angle Class III

Keywords

Class III treatment, Modified Fixed Mandibular Retractor Appliance, RCT

Brief summary

This experimental study aims to evaluate the efficiency of the Modified Fixed Mandibular Retractor Appliance in the treatment of skeletal class III malocclusion. The study sample will consist of 44 patients with skeletal class III malocclusion. The sample will be allocated randomly into two groups: experimental group and untreated control group. The soft and hard tissue changes will be assessed using lateral cephalometric radiographs before the treatment and after obtaining 3mm positive overjet.

Detailed description

This research aimes to evaluate the effects of a Class III functional appliance \[the modified fixed mandibular retractor (MFMR)\] in the early treatment of skeletal Class III deformities. It was not ethical to expose all candidate children to radiographic examination. Therefore, the assessment of skeletal Class III malocclusion was based on clinical judgment. Each patient was examined, while his/her mandible was kept at its retruded contact position to evaluate both jaws in space. Those who met the inclusion criteria were then sent to the radiographic department. The radiographic lateral cephalograms were obtained in the patients' habitual occlusion. All patients in the treatment group were treated by one specialist orthodontist 'AA' using the MFMR. The appliance consisted of the following elements: (1) Two acrylic upper posterior bite planes which cover the deciduous and permanent molars ( 2) Two transpalatal arch (0.8-mm TMA) with opposite U loop, the anterior one is near the first deciduous molars while the posterior one is near the first permanent molars (3) upper reversed labial bow (0.9-mm stainless steel) extending to the cervical edges of the mandibular anterior teeth from the labial surface of the lower primary canine on one side to the other labial surface of the contralateral tooth. This bow will be activated to hold the mandible in its maximum posterior physiologic position; and (4) the anterior spring (0.8-mm TMA) which starts from the acrylic bite plane in both sides, makes loop, then bends to touch the cingulum of upper incisors to procline the upper permanent incisors when diagnosed as retroclined. The untreated group will receive no orthodontic treatment during the observation period. According to the Dental School Local Research Ethics Committee's guidelines, all children in the untreated group will receive orthodontic treatment after the end of the observational period of the study at no cost.

Interventions

DEVICEModified Fixed Mandibular Retractor Appliance

All patients with Class III malocclusion will be treated using the Modified Fixed Mandibular Retractor Appliance

Sponsors

Damascus University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)

Masking description

A person who is not related to the research will paste a piece of paper over the Patient's name and the date of the photo then will give each x-ray a code and blind these codes on the researcher during the assessing process.

Eligibility

Sex/Gender
ALL
Age
7 Years to 9 Years
Healthy volunteers
No

Inclusion criteria

* Patients in early mixed dentation (7-9 years old). * Skeletal class III caused by mandibular prognathism with or without maxillary deficiency judged clinically and confirmed radiographically (ANB≤1). * Anterior crossbite on two teeth or more. * Normal inclination of the lower incisors with the mandibular plane. * Good oral hygiene.

Exclusion criteria

* Poor oral hygiene. * Previous orthodontic treatment. * Patients with syndromes, clefts, or craniofacial abnormalities. * Severe skeletal class III resulting primarily from mandibular prognathism (ANB less than - 4 with no functional shift on closure) * Patients with facial asymmetry. * Patients with vertical growth pattern.

Design outcomes

Primary

MeasureTime frameDescription
ANB angle changesChanges will be evaluated before treatment and after obtaining 3mm positive overjet, which will take approximately 8 monthsANB angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs.

Secondary

MeasureTime frameDescription
SNA angle changesChanges will be evaluated before treatment and after obtaining 3mm positive overjet, which will take approximately 8 monthsSNA angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs.
SNB angle changesChanges will be evaluated before treatment and after obtaining 3mm positive overjet, which will take approximately 8 monthsSNB angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs.
Profile changesChanges will be evaluated before treatment and after obtaining 3mm positive overjet, which will take approximately 8 monthsProfile changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs.
Upper incisor angle changesChanges will be evaluated before treatment and after obtaining 3mm positive overjet, which will take approximately 8 monthsUpper incisor angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs.
Lower incisor angle changesChanges will be evaluated before treatment and after obtaining 3mm positive overjet, which will take approximately 8 monthsLower incisor angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs.

Countries

Syria

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026