Comparison of Treatment Effects of PowerScope2 and Forsus Using CBCT
Condition: Class II Division 1 Malocclusion
MeSH terms: Malocclusion
Study type: Interventional

Summary: 
      The main objective of this prospective, controlled clinical study is:

        1. To compare the treatment effects of PowerScope2 and Forsus Fatigue Resistant Device in
           patients with Class II divison1 malocclusion.

        2. To compare the treatment effects of PowerScope2 and Forsus Fatigue Resistant Device with
           the control group.

      The null hypothesis for this study is that Forsus and PowerScope2 are equally effective in
      the treatment of ClassII div1 malocclusion.
    

Detailed description: 
      Class II malocclusion is one of the most frequent problems in orthodontics ,as it affects one
      third of patients seeking orthodontic treatment. McNamara reported mandibular retrusion as
      the most common characteristic of Class II malocclusion rather than maxillary prognathism.
      Functional orthopaedic appliances are widely used to treat Class II malocclusion in growing
      patients .Contrary to removable appliances, fixed devices do not require patient
      collaboration and can be worn in association with multibracket therepy, so that class II
      malocclusion can be corrected in a single phase treatment.

      .Most popular flexible devices are the Jasper Jumper, Eureka spring, and the Forsus device
      (FRD)Forsus Fatigue Resistant Device [FRD]is a three piece (L pin module) or two-piece (EZ2
      module) system, composed of a telescoping spring that attaches at upper first molar and a
      push rod linked to lower archwire, distal to either the canine or first premolar bracket. The
      FRD spring and rod create an equal and opposite force to maxillary and mandibular
      dentition.1The clinical application of the FRD was described by Vogt in 2006.PowerScope is
      one of the latest innovation in Class II correction developed by Dr. Andy Hayes. Inventors
      claims the following advantages of powerscope over other functional appliances. It is
      delivered as a one-size-fits-all appliance pre-assembled with attachment nuts for quick and
      easy chairside application .

      The appliance is a wire-to-wire installation with attachments placed mesial to the first
      molar in the maxillary arch and distal to the canine of the mandibular arch. Internal NiTi
      spring mechanism delivers 260 gms of force for continous activation during treatment.

      The dental, skeletal and soft tissue short-term effects of comprehensive fixed appliance
      treatment combined with ForsusTM in ClassII patients have been evaluated previously. However
      no previous study compared the posttreatment effects of PowerScope2TM and ForsusTM.The
      purpose of this controlled clinical study is to evaluate the treatment and posttreatment
      effects induced by PowerScope2 in growing patients with ClassII malocclusion and to compare
      it with Forsus(FRD) on CBCT.

      The majority of the studies examined the changes of the upper airway through lateral
      cephalometric radiography. This method limited the accuracy of airway measurement since the
      two-dimensional (2D) images only allowed an anteroposterior dimension measurement in sagittal
      plane, and failed to provide a full-scaled view of the upper airway. Therefore, 3D evaluation
      of the upper airway in growing patients during fixed functional appliance treatment needs to
      be established .Cone beam computed tomography (CBCT) is an acceptable technique for 3D
      volumetric depiction and morphological evaluation of the upper airway using a lower-radiation
      method with a greater spatial resolution . It allows 3D registration of pre- and
      post-treatment data through identification of specific structures in the cranial base.
      Therefore, the changes of the upper airway before and after mandibular advancement can be
      precisely evaluated. As the patients involved in our research were underage, their normal
      development may affect on the upper airway morphology during the treatment period. Thus, an
      untreated control group is needed. In the present study, the control group was selected from
      records of patients with the same diagnosis who just began orthodontic treatment, and matches
      well with the post-treatment patients of fixed functional appliance group through age, sex
      and development condition strategy, so that effects of fixed functional appliance on the
      upper airway morphology can be evaluated.

      MATERIALS AND METHODS- Ours is a prospective, non-pharmacological, double blind, randomized
      controlled clinical study to compare the treatment effects of two different fixed functional
      appliances, Forsus and PowerScope2. The present study will be conducted in the Department of
      Orthodontics and Dentofacial Orthopedics, PGIDS, Pt. B.D. Sharma University of Health
      Sciences, Rohtak.

      Ethical clearance- The study will be carried out after the institutional approval for use in
      humans.

      Source of data:- The sample size consists of 63 subjects who were selected from the patients
      attending regular OPD at the Department of Orthodontics and Dentofacial Orthopedics for
      orthodontic treatment.

      TARGET SAMPLE SIZE Nearly 21 subjects per group and 63 in total should be an ideal sample
      size including 10% dropout for the proposed study to have a power of 90% and a standard error
      of significance to be 0.05.

      INFORMED CONSENT OF THE PATIENT AND AGREEMENT TO BE RANDOMISED A valid, informed written
      consent of the patient or parent/ guardian and an agreement to be randomized was obtained
      from the patient before registering the patient in this clinical study. Patient or parent/
      guardian was informed about all the theoretical risks and benefits of the intervention under
      test. Risks and hazards of radiation during CBCT were also explained to the patient.

      INTERVENTION AND DESIGN OF STUDY

      The main intervention in this clinical study is placement of 2 different fixed functional
      appliances after initial levelling and alignment of dental arches. The study consists of 3
      groups with equal allocation of subjects in each group-

      G1- This group received Powerscope2 appliance bilaterally G2-This group received Forsus
      bilaterally (as per size suitable for the individual.

      G3-The control group wiil be selected from patients with same diagnosis who just began
      orthodontic treatment, and matches well with the post treatment patients of Powerscope2 and
      Forsus through age, sex and development condition.

      Selection of subjects in intervention groups (patients meeting selection criteria)

      Treatment with 0.022 MBT preadjusted edgewise appliance

      Maxillary and mandibular arches will be stabilized with the help of 0.019" × 0.025" stainless
      steel wire, reverse torque will be introduced in the lower anterior segment and wires will be
      cinched back distal to 2ndmolars.

      Patient were randomly allocated into 2 groups.

      1 PowerScope2 (G1) 2. Forsus (G2)

      Pretreatment diagnostic records including lateral cephalogram were taken. CBCT was taken
      before insertion and after removal of the fixed functional appliance.

      Insertion of fixed functional appliance as per the group allocated. Regular follow up till
      the completion of functional phase of treatment will be done. Patients will undergo
      functional appliance phase till Class I molar relationship is achieved.

      RANDOMISATION & ALLOCATION CONCEALMENT The subjects were randomly allocated by a sealed
      opaque envelope method. The study subjects were blinded regarding intervention group.
      Allocated appliance was inserted on the patient.

      DATA COLLECTION AND CBCT ANALYSIS

      The investigator recorded the patients' name, address and contact number. CBCT will be
      recorded before placement of fixed functional appliance and immediately after its removal in
      order to evaluate changes caused by the functional appliances.

      To check patient comfort, all patients were given a questionnaire to investigate the
      patient's experiences with PowerScope2 and Forsus. The questionnaire was designed in English
      and then verbally translated into the patients and parents native language at the
      installation appointment though all the patients and their parents could read and understand
      it in English.

      Prefunctional and postfunctional profile photographs of the treatment groups (G1 and G2)
      patients and those of control will be presented to 5 orthodontists, 5 patients, 5 parents and
      5 laypersons.The raters will assess changes in facial appearance on a visual analog scale.

      CBCT Data Acquisition The pre-treatment and post-treatment CBCT scans of two intervention
      groups (G1 & G2) and the CBCT of control group (G3) will be collected and analysed.

      During CBCT scan, patients will be instructed to maintain an upright posture and natural head
      position. The CBCT scans will be performed at rest position of the tongue (tongue in contact
      with anterior palate without touching the anterior teeth) and maximum intercuspation. All of
      the scans will be performed by the same researcher.

      DATA COLLECTION & INTERPRETATION Data will be collected, properly arranged and a CONSORT flow
      chart will be made to derive final sample size and calculate number of exclusions.

      Statistical analysis:-The data recorded will be processed by standard statistical analysis.
    

Intervention name(s): Class II correction using PowerScope2; Class II correction using Forsus
Intervention type(s): Device; Device
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment