Tooth Crowding, Dental Crowding, Malocclusion
Conditions
Keywords
archwire dimension, ligation method, bracket type
Brief 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.
Interventions
.014 CuNiTi orthodontic arch wire
.016 CuNiTi orthodontic arch wire
Ormco Insignia Metal Twin brackets
Ormco Insignia SL brackets
Sponsors
Study design
Masking description
Neither subjects nor the treating orthodontists will know whether a .014 or 0.16 dimension wire is being used. The investigator will assign wire dimensions using a random number generator and distribute the wires to the treating orthodontists with the archwire dimension number removed from the package. The outcomes assessor will be blinded as to which patients were treated with which archwires while analyzing the digital models of the teeth. Because there is a clear visual difference between twin and self-ligating brackets, there will be no blinding with regard to ligation method (bracket type).
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.
Eligibility
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)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Little's Index From Baseline to 6 Weeks | Baseline and 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). |
| Change in Little's Index From 6 Weeks to 12 Weeks | 6 weeks and 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). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Baseline and 6 weeks | 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. |
| Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Baseline and 6 weeks | 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. |
| Correlation Between Degrees of Malalignment and Rate of Tooth Movement | Baseline and 12 weeks | A repeated measure linear regression model conducted to evaluate any correlation between the degrees of malalignment and the rate of tooth movement. |
| Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | 6 weeks and 12 weeks | 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. |
| Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | 6 weeks and 12 weeks | 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. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| .014 With Twin Brackets .014 dimension CuNiTi orthodontic arch wires and .022 slot Ormco Insignia Metal Twin brackets.
.014: .014 CuNiTi orthodontic arch wire
Twin brackets: Ormco Insignia Metal Twin brackets | 9 |
| .016 With Twin Brackets .016 dimension CuNiTi orthodontic arch wires and .022 slot Ormco Insignia Metal Twin brackets.
.016: .016 CuNiTi orthodontic arch wire
Twin brackets: Ormco Insignia Metal Twin brackets | 9 |
| .014 With Self-ligating Brackets .014 dimension CuNiTi orthodontic arch wires and .022 slot Ormco Insignia SL (self-ligating) brackets.
.014: .014 CuNiTi orthodontic arch wire
Self-ligating brackets: Ormco Insignia SL brackets | 9 |
| .016 With Self-ligating Brackets .016 dimension CuNiTi orthodontic arch wires and .022 slot Ormco Insignia SL (self-ligating) brackets.
.016: .016 CuNiTi orthodontic arch wire
Self-ligating brackets: Ormco Insignia SL brackets | 9 |
| Total | 36 |
Baseline characteristics
| Characteristic | .016 With Twin Brackets | .014 With Self-ligating Brackets | .016 With Self-ligating Brackets | Total | .014 With Twin Brackets |
|---|---|---|---|---|---|
| Age, Continuous | 14.4 years STANDARD_DEVIATION 2.2 | 14.9 years STANDARD_DEVIATION 2.7 | 18.0 years STANDARD_DEVIATION 6.4 | 16.2 years STANDARD_DEVIATION 4.2 | 17.2 years STANDARD_DEVIATION 3.4 |
| Race and Ethnicity Not Collected | — | — | — | 0 Participants | — |
| Region of Enrollment United States | 9 Participants | 9 Participants | 9 Participants | 36 Participants | 9 Participants |
| Sex: Female, Male Female | 5 Participants | 6 Participants | 4 Participants | 20 Participants | 5 Participants |
| Sex: Female, Male Male | 4 Participants | 3 Participants | 5 Participants | 16 Participants | 4 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 9 | 0 / 9 | 0 / 9 | 0 / 9 |
| other Total, other adverse events | 0 / 9 | 0 / 9 | 0 / 9 | 0 / 9 |
| serious Total, serious adverse events | 0 / 9 | 0 / 9 | 0 / 9 | 0 / 9 |
Outcome results
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).
Time frame: 6 weeks and 12 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| .014 With Twin Brackets | Change in Little's Index From 6 Weeks to 12 Weeks | -0.8 mm | Standard Deviation 1 |
| .016 With Twin Brackets | Change in Little's Index From 6 Weeks to 12 Weeks | -0.9 mm | Standard Deviation 0.8 |
| .014 With Self-ligating Brackets | Change in Little's Index From 6 Weeks to 12 Weeks | -0.2 mm | Standard Deviation 0.7 |
| .016 With Self-ligating Brackets | Change in Little's Index From 6 Weeks to 12 Weeks | -0.4 mm | Standard Deviation 0.8 |
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).
Time frame: Baseline and 6 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| .014 With Twin Brackets | Change in Little's Index From Baseline to 6 Weeks | -2.5 mm | Standard Deviation 2.2 |
| .016 With Twin Brackets | Change in Little's Index From Baseline to 6 Weeks | -2.9 mm | Standard Deviation 1.8 |
| .014 With Self-ligating Brackets | Change in Little's Index From Baseline to 6 Weeks | -2.3 mm | Standard Deviation 1.8 |
| .016 With Self-ligating Brackets | Change in Little's Index From Baseline to 6 Weeks | -2.6 mm | Standard Deviation 2.4 |
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.
Time frame: 6 weeks and 12 weeks
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| .014 With Twin Brackets | Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Rotation around the x-axis | .82 degrees | Standard Deviation 2 |
| .014 With Twin Brackets | Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Rotation around the z-axis | .16 degrees | Standard Deviation 1.33 |
| .014 With Twin Brackets | Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Rotation around the y-axis | .86 degrees | Standard Deviation 2.13 |
| .016 With Twin Brackets | Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Rotation around the x-axis | 1.07 degrees | Standard Deviation 1.81 |
| .016 With Twin Brackets | Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Rotation around the z-axis | .18 degrees | Standard Deviation 0.83 |
| .016 With Twin Brackets | Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Rotation around the y-axis | .39 degrees | Standard Deviation 1.34 |
| .014 With Self-ligating Brackets | Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Rotation around the y-axis | .40 degrees | Standard Deviation 1.08 |
| .014 With Self-ligating Brackets | Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Rotation around the x-axis | .66 degrees | Standard Deviation 1.5 |
| .014 With Self-ligating Brackets | Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Rotation around the z-axis | -.13 degrees | Standard Deviation 1.21 |
| .016 With Self-ligating Brackets | Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Rotation around the x-axis | .40 degrees | Standard Deviation 1.59 |
| .016 With Self-ligating Brackets | Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Rotation around the z-axis | -.68 degrees | Standard Deviation 2.21 |
| .016 With Self-ligating Brackets | Angular Change in Tooth Position From 6 Weeks to 12 Weeks (Rotation) | Rotation around the y-axis | -.10 degrees | Standard Deviation 1.33 |
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.
Time frame: Baseline and 6 weeks
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| .014 With Twin Brackets | Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Rotation around the x-axis | 1.95 degrees | Standard Deviation 3.09 |
| .014 With Twin Brackets | Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Rotation around the z-axis | .66 degrees | Standard Deviation 1.54 |
| .014 With Twin Brackets | Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Rotation around the y-axis | 1.37 degrees | Standard Deviation 1.71 |
| .016 With Twin Brackets | Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Rotation around the x-axis | 1.52 degrees | Standard Deviation 2.84 |
| .016 With Twin Brackets | Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Rotation around the z-axis | .79 degrees | Standard Deviation 1.1 |
| .016 With Twin Brackets | Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Rotation around the y-axis | .99 degrees | Standard Deviation 1.26 |
| .014 With Self-ligating Brackets | Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Rotation around the y-axis | 1.33 degrees | Standard Deviation 1.99 |
| .014 With Self-ligating Brackets | Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Rotation around the x-axis | 1.97 degrees | Standard Deviation 2.47 |
| .014 With Self-ligating Brackets | Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Rotation around the z-axis | .95 degrees | Standard Deviation 1.45 |
| .016 With Self-ligating Brackets | Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Rotation around the x-axis | 1.91 degrees | Standard Deviation 3.17 |
| .016 With Self-ligating Brackets | Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Rotation around the z-axis | 1.59 degrees | Standard Deviation 3.21 |
| .016 With Self-ligating Brackets | Angular Change in Tooth Position From Baseline to 6 Weeks (Rotation) | Rotation around the y-axis | 1.78 degrees | Standard Deviation 2.5 |
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.
Time frame: Baseline and 12 weeks
Population: Due to loss of key study personnel these data were not collected
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.
Time frame: 6 weeks and 12 weeks
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| .014 With Twin Brackets | Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Translation along the x-axis | .05 mm | Standard Deviation 0.08 |
| .014 With Twin Brackets | Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Translation along the z-axis | -.16 mm | Standard Deviation 0.32 |
| .014 With Twin Brackets | Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Translation along the y-axis | .03 mm | Standard Deviation 0.24 |
| .016 With Twin Brackets | Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Translation along the x-axis | .05 mm | Standard Deviation 0.2 |
| .016 With Twin Brackets | Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Translation along the z-axis | .00 mm | Standard Deviation 0.22 |
| .016 With Twin Brackets | Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Translation along the y-axis | .03 mm | Standard Deviation 0.13 |
| .014 With Self-ligating Brackets | Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Translation along the y-axis | -.01 mm | Standard Deviation 0.09 |
| .014 With Self-ligating Brackets | Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Translation along the x-axis | .01 mm | Standard Deviation 0.11 |
| .014 With Self-ligating Brackets | Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Translation along the z-axis | -.07 mm | Standard Deviation 0.23 |
| .016 With Self-ligating Brackets | Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Translation along the x-axis | .03 mm | Standard Deviation 0.17 |
| .016 With Self-ligating Brackets | Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Translation along the z-axis | .00 mm | Standard Deviation 0.15 |
| .016 With Self-ligating Brackets | Linear Change in Tooth Position From 6 Weeks to 12 Weeks (Translation) | Translation along the y-axis | .03 mm | Standard Deviation 0.18 |
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.
Time frame: Baseline and 6 weeks
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| .014 With Twin Brackets | Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Translation along the x-axis | .03 mm | Standard Deviation 0.15 |
| .014 With Twin Brackets | Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Translation along the z-axis | -.23 mm | Standard Deviation 0.34 |
| .014 With Twin Brackets | Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Translation along the y-axis | .05 mm | Standard Deviation 0.09 |
| .016 With Twin Brackets | Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Translation along the x-axis | -.05 mm | Standard Deviation 0.18 |
| .016 With Twin Brackets | Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Translation along the z-axis | -.18 mm | Standard Deviation 0.28 |
| .016 With Twin Brackets | Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Translation along the y-axis | .03 mm | Standard Deviation 0.21 |
| .014 With Self-ligating Brackets | Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Translation along the y-axis | -.08 mm | Standard Deviation 0.12 |
| .014 With Self-ligating Brackets | Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Translation along the x-axis | -.14 mm | Standard Deviation 0.28 |
| .014 With Self-ligating Brackets | Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Translation along the z-axis | -.22 mm | Standard Deviation 0.3 |
| .016 With Self-ligating Brackets | Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Translation along the x-axis | -.09 mm | Standard Deviation 0.23 |
| .016 With Self-ligating Brackets | Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Translation along the z-axis | -.28 mm | Standard Deviation 0.47 |
| .016 With Self-ligating Brackets | Linear Change in Tooth Position From Baseline to 6 Weeks (Translation) | Translation along the y-axis | .06 mm | Standard Deviation 0.34 |