Treatment of Class III Malocclusion Using Modified Fixed Mandibular Retractor Appliance

• ClinicalTrials.gov Identifier: NCT03354442
• Recruitment Status: Completed
• First Posted: November 28, 2017
• Last Update Posted: July 18, 2019
• Sponsor: Damascus University
• Information provided by (Responsible Party): Damascus University

Study Description

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.

Condition or disease	Intervention/treatment	Phase
Malocclusion, Angle Class III	Device: Modified Fixed Mandibular Retractor Appliance	Not Applicable

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.

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 44 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• 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.
• Primary Purpose: Treatment
• Official Title: Evaluation of the Efficacy of Modified Fixed Mandibular Retractor Appliance in the Treatment of Class III Malocclusion: A Clinical Randomized Controlled Trial
• Actual Study Start Date: May 15, 2017
• Actual Primary Completion Date: December 20, 2017
• Actual Study Completion Date: January 10, 2019

Arms and Interventions

Arm	Intervention/treatment
Experimental: Modified Fixed Mandibular Retractor; All patients in this group will be treated using Modified Fixed Mandibular Retractor Appliance. This appliance will be used full-time.	Device: Modified Fixed Mandibular Retractor Appliance; All patients with Class III malocclusion will be treated using the Modified Fixed Mandibular Retractor Appliance
No Intervention: Untreated control group; All patients in this group will be observed during the period of treating the patients in the other group to assess the growth changes.

Outcome Measures

Primary Outcome Measures :

1. ANB angle changes [ Time Frame: Changes will be evaluated before treatment and after obtaining 3mm positive overjet, which will take approximately 8 months ]
   ANB angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs.

Secondary Outcome Measures :

1. SNA angle changes [ Time Frame: Changes will be evaluated before treatment and after obtaining 3mm positive overjet, which will take approximately 8 months ]
   SNA angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs.
2. SNB angle changes [ Time Frame: Changes will be evaluated before treatment and after obtaining 3mm positive overjet, which will take approximately 8 months ]
   SNB angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs.
3. Profile changes [ Time Frame: Changes will be evaluated before treatment and after obtaining 3mm positive overjet, which will take approximately 8 months ]
   Profile changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs.
4. Upper incisor angle changes [ Time Frame: Changes will be evaluated before treatment and after obtaining 3mm positive overjet, which will take approximately 8 months ]
   Upper incisor angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs.
5. Lower incisor angle changes [ Time Frame: Changes will be evaluated before treatment and after obtaining 3mm positive overjet, which will take approximately 8 months ]
   Lower incisor angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs.

Eligibility Criteria

• Ages Eligible for Study: 7 Years to 9 Years (Child)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Criteria

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.

Contacts and Locations

Locations

Syrian Arab Republic

Damascus University

Damascus, Syrian Arab Republic, 00963

Sponsors and Collaborators

Damascus University

Investigators

• Study Chair: Ahmad S Burhan, PhD.; Department of Orthodontics, Faculty of Dentistry, Damascus University, Damascus, Syria

More Information

Publications:

Alhaija ES. Skeletal, dental and soft tissue changes in postural class III malocclusion treated with a maxillary removable appliance. J Clin Pediatr Dent. 2006 Winter;31(2):149-52.

Akin M, Ucar FI, Chousein C, Sari Z. Effects of chincup or facemask therapies on the orofacial airway and hyoid position in Class III subjects. J Orofac Orthop. 2015 Nov;76(6):520-30. doi: 10.1007/s00056-015-0315-3.

Majanni AM, Hajeer MY. The Removable Mandibular Retractor vs the Bone-anchored Intermaxillary Traction in the Correction of skeletal class III Malocclusion in children: A Randomized Controlled Trial. J Contemp Dent Pract. 2016 May 1;17(5):361-71.

Seehra J, Fleming PS, Mandall N, Dibiase AT. A comparison of two different techniques for early correction of Class III malocclusion. Angle Orthod. 2012 Jan;82(1):96-101. doi: 10.2319/032011-197.1. Epub 2011 Aug 1.

Atalay Z, Tortop T. Dentofacial effects of a modified tandem traction bow appliance. Eur J Orthod. 2010 Dec;32(6):655-61. doi: 10.1093/ejo/cjp153. Epub 2010 Mar 26.

Kapur A, Chawla HS, Utreja A, Goyal A. Early class III occlusal tendency in children and its selective management. J Indian Soc Pedod Prev Dent. 2008 Sep;26(3):107-13.

• Responsible Party: Damascus University
• ClinicalTrials.gov Identifier: NCT03354442
• Other Study ID Numbers: UDDS-Ortho-08-2017
• First Posted: November 28, 2017
• Last Update Posted: July 18, 2019
• Last Verified: July 2019

Individual Participant Data (IPD) Sharing Statement:

• Plan to Share IPD: No
• Plan Description: The Individual participant data will be only available for the researchers in the department of Orthodontics, Damascus University

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Damascus University:

Class III treatment; Modified Fixed Mandibular Retractor Appliance; RCT

Additional relevant MeSH terms:

Prognathism; Malocclusion; Malocclusion, Angle Class III; Tooth Diseases; Stomatognathic Diseases; Jaw Abnormalities; Jaw Diseases; Musculoskeletal Diseases; Mandibular Diseases; Maxillofacial Abnormalities; Craniofacial Abnormalities; Musculoskeletal Abnormalities; Stomatognathic System Abnormalities; Congenital Abnormalities