Analysis of Orthodontic Tooth Movement Using 3D Imaging

Study Overview
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Brief Summary
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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
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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: To analyze the effect of wire dimension (.014 vs. .016) and time-course (first six weeks or second six weeks) on Stage I treatment To correlate clinical tooth movements with bench data for four types of malalignment In-out Rotation Tip Vertical step 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.

Official Title
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Analysis of Orthodontic Tooth Movement Using 3D Imaging

Conditions
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Tooth Crowding, Dental Crowding, Malocclusion

Intervention / Treatment
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* Device: .014
* Device: .016
* Device: Twin brackets
* Device: Self-ligating brackets


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: In the initial stage of active treatment at the University of North Carolina graduate orthodontic clinic or Selden Orthodontics Non-extraction treatment Maxillary and mandibular Little Index between 1-15 mm (this is a measurement of crowding) Presence of all permanent anterior teeth Age 10-45 years Consent to participate in the study Exclusion Criteria: Systemic diseases such as diabetes, hypertension, temporomandibular disorders (TMD), craniofacial syndrome, etc. Any spacing between anterior teeth Subjects who have incisor mandibular plane angle (IMPA) greater than or equal to 100 degrees Anterior tooth completely blocked from the arch form Periodontal pocketing of any teeth greater than 4 mm Maxillary and mandibular Little Index >15 mm (This is a measurement of crowding. A Little Index of >15 mm indicates a need for a smaller dimension arch wire)

Ages Eligible for Study
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Minimum Age: 10 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional 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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: .014 with twin brackets<br>.014 dimension CuNiTi orthodontic arch wires and .022 slot Ormco Insignia Metal Twin brackets. | Device: .014<br>* .014 CuNiTi orthodontic arch wire<br>Device: Twin brackets<br>* Ormco Insignia Metal Twin brackets<br>|
| Active Comparator: .016 with twin brackets<br>.016 dimension CuNiTi orthodontic arch wires and .022 slot Ormco Insignia Metal Twin brackets. | Device: .016<br>* .016 CuNiTi orthodontic arch wire<br>Device: Twin brackets<br>* Ormco Insignia Metal Twin brackets<br>|
| Active Comparator: .014 with self-ligating brackets<br>.014 dimension CuNiTi orthodontic arch wires and .022 slot Ormco Insignia SL (self-ligating) brackets. | Device: .014<br>* .014 CuNiTi orthodontic arch wire<br>Device: Self-ligating brackets<br>* Ormco Insignia SL brackets<br>|
| Active Comparator: .016 with self-ligating brackets<br>.016 dimension CuNiTi orthodontic arch wires and .022 slot Ormco Insignia SL (self-ligating) brackets. | Device: .016<br>* .016 CuNiTi orthodontic arch wire<br>Device: Self-ligating brackets<br>* Ormco Insignia SL brackets<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Little's Index From Baseline to 6 Weeks | Little's Index measures the distance between contact points on adjacent teeth. Little's Index will be measured at two time points (0 weeks and 6 weeks). | Baseline and 6 weeks | 
| Change in Little's Index From 6 Weeks to 12 Weeks | Little's Index measures the distance between contact points on adjacent teeth. Little's Index will be measured at two time points (6 weeks and 12 weeks). | 6 weeks and 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Clinical linear measurements (mm) in x-, y-, and z-translation will be measured at two time points (0 weeks and 6 weeks) to determine the linear (translational) change in tooth position during that time. | Baseline and 6 weeks | 
| Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Clinical linear measurements (mm) in x-, y-, and z-translation will be measured at two time points (6 weeks and 12 weeks) to determine the linear (translational) change in tooth position during that time. | 6 weeks and 12 weeks | 
| Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Clinical angular measurements (degree) in x-, y-, and z-rotation will be measured at two time points (0 weeks and 6 weeks) to determine the angular (rotational) change in tooth position during that time. | Baseline and 6 weeks | 
| Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Clinical angular measurements (degree) in x-, y-, and z-rotation will be measured at two time points (6 weeks and 12 weeks) to determine the angular (rotational) change in tooth position during that time. | 6 weeks and 12 weeks | 
| Correlation Between Degrees of Malalignment and Rate of Tooth Movement | A repeated measure linear regression model conducted to evaluate any correlation between the degrees of malalignment and the rate of tooth movement. | Baseline and 12 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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archwire dimension, ligation method, bracket type