Analysis of Orthodontic Tooth Movement Using 3D Imaging
Condition: Tooth Crowding; Dental Crowding; Malocclusion
MeSH terms: Malocclusion
Study type: Interventional

Summary: 
      Purpose: This project aims to study the effects of wire dimension and ligation method
      (bracket type) on the first stage of orthodontic treatment using 3D imaging.

      Participants: Up to 80 patients at UNC School of Dentistry or Selden Orthodontics between the
      ages of 10 and 45, inclusive, who have been previously diagnosed with malocclusion requiring
      orthodontic treatment (braces) and are otherwise healthy.

      Procedures (methods): Subjects receiving standard of care (SOC) orthodontic treatment will be
      randomized to one of two commonly used orthodontic archwires (.014" or .016" diameter).
      Subjects will be further subdivided for analysis based on the type of bracket (twin or
      self-ligating) that their clinician uses in their treatment. We will review the 3D digital
      images of each subject's dentition recorded as part of SOC at the 0-, 6- and 12-week visits.
      We will retrieve the archwires when they are removed per SOC by the clinician at the 12-week
      time point.
    

Detailed description: 
      Many archwire dimensions and two main bracket types (twin and self-ligating) are available to
      orthodontists for the first stage of orthodontic treatment, but little objective clinical
      evidence is available to indicate which archwire dimension and bracket type is ideal for a
      given patient with an individual type and degree of malalignment during this stage. A limited
      clinical trial will be conducted to collect and analyze this data.

      The aim of this study is to study the effect of wire dimension, timing and ligation method on
      leveling and aligning in orthodontic treatment using 3D imaging.

      The study's specific aims are as follows:

        1. To analyze the effect of wire dimension (.014" vs. .016") and time-course (first six
           weeks or second six weeks) on Stage I treatment

        2. To correlate clinical tooth movements with bench data for four types of malalignment

             1. In-out

             2. Rotation

             3. Tip

             4. Vertical step

        3. To analyze the effect of ligation method (twin vs. self-ligating) on Stage I treatment

      These specific aims will serve to address the following hypothesis: Archwire dimension
      affects tooth movement in Stage I of orthodontic treatment, depending upon variation
      time-course (due to force decay of superelastic wires) and method of ligation (bracket type).
      This will be tested in a total of 80 patients who are undergoing active treatment in the
      University of North Carolina (UNC) orthodontic graduate clinic or at Selden Orthodontics.
      There will be four different groups in this study. In the twin bracket cohort, half the
      patients will be treated with .014" dimension wire and half will be treated with .016"
      dimension wire. In the self-ligating bracket cohort, half the patients will be treated with
      .014" dimension wire, and half will be treated with .016" dimension wire.

      If the hypotheses are shown to be correct, then the subset of society receiving orthodontic
      treatment will be able to benefit from selection of bracket types and archwire dimensions
      that match their individual types and degrees of malalignment. This will allow for more
      efficient tooth movement with less unwanted movement, and could lead to shorter treatment
      times and less discomfort.
    

Intervention name(s): .014"; .016"; Twin brackets; Self-ligating brackets
Intervention type(s): Device; Device; Device; Device
Intervention description(s): .014" CuNiTi orthodontic arch wire; .016" CuNiTi orthodontic arch wire; Ormco Insignia Metal Twin brackets; Ormco Insignia SL brackets
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: There will be four different groups in this study, with each planned to consist of 20 patients (40 dental arches).
In the twin bracket cohort, 40 dental arches are planned to be treated with .014" dimension wire, and 40 dental arches are planned to be treated with .016" dimension wire.
In the self-ligating bracket cohort, 40 dental arches are planned to be treated with .014" dimension wire, and 40 dental arches are planned to be treated with .016" dimension wire.
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary purpose: Treatment
Keywords: archwire dimension; ligation method; bracket type