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Micro-implant Uprighting cantilever for the correction of a severely rotated and angulated mandibular canine during clear aligner treatment

Australasian Orthodontic Journal
Volume 41 (2025): Issue 1 (January 2025)
By:
Open Access
|Mar 2025

Figures & Tables

Figure 1.

Pre-treatment records, including extraoral and intraoral photographs.
Pre-treatment records, including extraoral and intraoral photographs.

Figure 2.

Pre-treatment radiographic records, including panoramic and lateral cephalogram.
Pre-treatment radiographic records, including panoramic and lateral cephalogram.

Figure 3.

Intraoral photographs after the bonding of bracketless nickel-titanium wires.
Intraoral photographs after the bonding of bracketless nickel-titanium wires.

Figure 4.

Treatment progress at eight months. A, Intraoral photographs. B, Model superimposition. The white colour denotes pre-treatment, and the dark colour represents the status at eight months. The registrations were performed on the occlusal surfaces of the first and second molars.
Treatment progress at eight months. A, Intraoral photographs. B, Model superimposition. The white colour denotes pre-treatment, and the dark colour represents the status at eight months. The registrations were performed on the occlusal surfaces of the first and second molars.

Figure 5.

Treatment progress at 12.5 months. A. Intraoral photographs. B. Model superimposition. The white colour denotes the model at eight months, and the dark colour represents the 12.5 month stage. The registrations were performed on the occlusal surfaces of the first and second molars.
Treatment progress at 12.5 months. A. Intraoral photographs. B. Model superimposition. The white colour denotes the model at eight months, and the dark colour represents the 12.5 month stage. The registrations were performed on the occlusal surfaces of the first and second molars.

Figure 6.

Hybrid mechanics illustration. Micro-implants are denoted by circles with cross-marks. Resin-wire bonding is represented by ovals on the crown surface. The white circles on the canine root indicate the centre of resistance. Dotted lines correspond to pre-activated cantilevers, while plain lines represent activated cantilevers. Striped arrows depict cantilever activating forces. White plain arrows show the activating force delivered to the canine. Black bold arrows represent the reactive forces. Circular arrows denote the force moment delivered to the canine. A, Oblique view. B, Occlusal view. C, The oblique view with aligners in place. D, The force diagram in the oblique view. E, The force diagram in the occlusal view.
Hybrid mechanics illustration. Micro-implants are denoted by circles with cross-marks. Resin-wire bonding is represented by ovals on the crown surface. The white circles on the canine root indicate the centre of resistance. Dotted lines correspond to pre-activated cantilevers, while plain lines represent activated cantilevers. Striped arrows depict cantilever activating forces. White plain arrows show the activating force delivered to the canine. Black bold arrows represent the reactive forces. Circular arrows denote the force moment delivered to the canine. A, Oblique view. B, Occlusal view. C, The oblique view with aligners in place. D, The force diagram in the oblique view. E, The force diagram in the occlusal view.

Figure 7.

Treatment progress at 15.5 months. A, Intraoral photographs. B, Model superimposition. The white colour denotes the model at 12.5 months, and the dark colour represents the 15.5-month stage. The registrations were performed on the occlusal surfaces of the first and second molars.
Treatment progress at 15.5 months. A, Intraoral photographs. B, Model superimposition. The white colour denotes the model at 12.5 months, and the dark colour represents the 15.5-month stage. The registrations were performed on the occlusal surfaces of the first and second molars.

Figure 8.

The additional cantilever placed on the left mandibular canine. A, Oblique view. B, Frontal view. C, Occlusal view.
The additional cantilever placed on the left mandibular canine. A, Oblique view. B, Frontal view. C, Occlusal view.

Figure 9.

Post-treatment records, including extraoral and intraoral photographs.
Post-treatment records, including extraoral and intraoral photographs.

Figure 10.

Model superimposition. The yellow colour denotes the pre-treatment model, and the orange colour represents the post-treatment model. The registrations were performed on the occlusal surfaces of the first and second molars. A, Maxillary dentition. B, Mandibular dentition. C, Oblique view.
Model superimposition. The yellow colour denotes the pre-treatment model, and the orange colour represents the post-treatment model. The registrations were performed on the occlusal surfaces of the first and second molars. A, Maxillary dentition. B, Mandibular dentition. C, Oblique view.

Figure 11.

Post-treatment radiographic records, including panoramic, lateral cephalogram, and the superimposition of cephalograms taken at pre- and post-treatment.
Post-treatment radiographic records, including panoramic, lateral cephalogram, and the superimposition of cephalograms taken at pre- and post-treatment.

Figure 12.

Voxel-based registration of the mandibular cone-beam computed tomography image. For simplicity, the post-treatment mandible was omitted. The yellow canine corresponds to the pre-treatment state, while the blue canine represents the post-treatment state. The orange-coloured arrows around the canines are the displacement vectors depicting the three-dimensional movements during treatment. A, Oblique view. B, Occlusal view.
Voxel-based registration of the mandibular cone-beam computed tomography image. For simplicity, the post-treatment mandible was omitted. The yellow canine corresponds to the pre-treatment state, while the blue canine represents the post-treatment state. The orange-coloured arrows around the canines are the displacement vectors depicting the three-dimensional movements during treatment. A, Oblique view. B, Occlusal view.

Figure 13.

Rotation and angulation measurements between the initial and the predicted or achieved models. The white model serves as the reference, while the dark model represents either the planned or achieved state. Reference lines are depicted with plain lines, and target lines as dotted lines. Arrows indicate the angles between the reference lines. A, Rotation. B, Angulation.
Rotation and angulation measurements between the initial and the predicted or achieved models. The white model serves as the reference, while the dark model represents either the planned or achieved state. Reference lines are depicted with plain lines, and target lines as dotted lines. Arrows indicate the angles between the reference lines. A, Rotation. B, Angulation.

Figure 14.

One year retention records, including extraoral and intraoral photographs.
One year retention records, including extraoral and intraoral photographs.

The right mandibular canine movement

MeasurementsBracketless NiTi (8 months)First CA Set (4.5 months)Second CA Set (3 months)Third CA Set (2.5 months)
Rotation
   Planned (°)—32.729.213.1
   Achieved (°)3.47.415.97.5
   Accuracy (%)—22.554.457.2
   Efficiency (°/month)0.41.65.33.0
Angulation (Root movement)
   Planned (°)—20.217.810.3
   Achieved (°)3.83.39.56.0
   Accuracy (%)—16.153.157.8
   Efficiency (°/month)0.50.73.22.4

Cephalometric measurements

MeasurementsNormPre-treatmentPost-treatment
Anterior Posterior
  SNA (°)82.182.482.4
  SNB (°)79.881.081.0
  ANB [°]2.31.41.4
Vertical
  FMA [°]23.521.521.5
  Gonial Angle (°)117.9118.2118.2
  FH-Occ (°)8.310.210.2
Dental
  U1 to FH (°)116.2110.9119.1
  IMPA [°]96.387.594.6
  Interincisal angle [°]124.1140.1124.8
Soft tissue
  Upper lip to E-line (mm)-0.8-3.7-4.0
  Lower lip to E-line (mm)0.5-0.7-2.7
DOI: https://doi.org/10.2478/aoj-2025-0002 | Journal eISSN: 2207-7480 | Journal ISSN: 2207-7472
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Language: English
Page range: 18 - 31
Submitted on: Oct 1, 2024
Accepted on: Jan 1, 2025
Published on: Mar 3, 2025
Published by: Australian Society of Orthodontists Inc.
In partnership with: Paradigm Publishing Services
Publication frequency: 1 times per year
Related subjects:
Medicine,
Basic medical science,
Basic medical science, other

© 2025 Hyung-Kyu Noh, Ho-Jin Kim, Hyo-Sang Park, published by Australian Society of Orthodontists Inc.
This work is licensed under the Creative Commons Attribution 4.0 License.

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