Treatment of Class III Malocclusion Using Modified Fixed Mandibular Retractor Appliance
Condition: Malocclusion, Angle Class III
MeSH terms: Prognathism; Malocclusion; Malocclusion, Angle Class III
Study type: Interventional

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.
    

Intervention name(s): Modified Fixed Mandibular Retractor Appliance
Intervention type(s): Device
Intervention description(s): All patients with Class III malocclusion will be treated using the Modified Fixed Mandibular Retractor Appliance
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Class III treatment; Modified Fixed Mandibular Retractor Appliance; RCT