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. 2025 Jun 24;13(7):286.
doi: 10.3390/dj13070286.

Three-Dimensional Comparison of CBCT and Intraoral Scans for Assessing Orthodontic Traction of Impacted Canines with Clear Aligners

Teresa Pinho  1   2 , João Pedro Carvalho  1
Affiliations

Three-Dimensional Comparison of CBCT and Intraoral Scans for Assessing Orthodontic Traction of Impacted Canines with Clear Aligners

Teresa Pinho et al. Dent J (Basel). .

Abstract

Background: Canine impaction complicates treatment and prolongs duration, requiring precise localization. CBCT is the gold standard for diagnosis and assessment. However, it involves high radiation exposure and cost. This study aimed to evaluate the effectiveness of a combined biomechanical approach for orthodontic traction of impacted maxillary canines (IMCs) and to determine whether intraoral scans (STL files) could replace a final CBCT in assessing canine repositioning. Methods: The sample included 10 patients (7 males and 3 females) with 13 severely displaced IMCs, treated with a protocol combining Invisalign® aligners, elastics, mini-implants, and sectional wires. In all, 9 IMC were palatally impacted, while 4 were buccally impacted. A representative clinical case is presented to illustrate the biomechanics used in one of the complex cases. Canine movement was evaluated at the cusp and apex through two methods: overlay of pre- and post-treatment CBCTs, and overlay of initial and final STL scans onto the initial CBCT. Results: A Class I canine relationship was successfully achieved in all patients. No statistically significant differences were found between the two measurement methods (p > 0.05). Conclusions: Orthodontic traction of IMC, especially in complex cases, can be achieved using aligners, elastics, mini-implants, and sectional wires. Once the canine crown has erupted and is clinically visible, STL scans overlaid with the initial CBCT can accurately assess the final position of the crown and root. This allows clinicians to avoid a second CBCT in selected cases, reducing patient radiation exposure while maintaining diagnostic accuracy.

Keywords: 3D imaging; clear aligners; cone-beam computed tomography; cuspid; impacted; tooth.

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Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Step-by-Step protocol for 3D evaluation of canine position using the STL overlay method. Abbreviations: ErC: Erupted Canine; IC: Impacted Canine.
Figure 2
Figure 2
Initial CBCT scan.
Figure 3
Figure 3
Initial CBCT after tooth segmentation.
Figure 4
Figure 4
Superimposition of segmented teeth from initial CBCT and initial STL.
Figure 5
Figure 5
Initial STL with the IC from the CBCT scan.
Figure 6
Figure 6
Superimposition of initial and final STL models using palatal rugae.
Figure 7
Figure 7
Final STL including the initial 3D position of the IC.
Figure 8
Figure 8
Overlay of canine in initial and final positions.
Figure 9
Figure 9
Cusp and apex displacement measurements.
Figure 10
Figure 10
Measurements of all palatally ICs in the sample (n = 9).
Figure 11
Figure 11
Measurements of all buccally ICs in the sample (n = 4).
Figure 12
Figure 12
Initial intraoral lateral photo.
Figure 13
Figure 13
Impacted canine 23 with its cusp palatally positioned to the apical half of the left lateral incisor, with the root significantly curved and inserted into the maxillary sinus.
Figure 14
Figure 14
Open surgical exposure of the canine with button fixation and ligature wire for subsequent traction.
Figure 15
Figure 15
Adjusted aligners, palatal mini-implant, and elastic chain used for distalizing the canine; 7 months after the surgery.
Figure 16
Figure 16
Sectional fixed appliance from teeth 11 to 26, with support for Class II elastics to improve sagittal relationship; 14 months after the surgery.
Figure 17
Figure 17
Ligature wire attached to a 0.014” nitinol archwire on the palatal surface of the canine; 14 months after the surgery.
Figure 18
Figure 18
Vestibular traction of the canine, gingival removal, and elastic use for vertical stabilization; 14 months after the surgery.
Figure 19
Figure 19
Extension of the sectional fixed appliance up to tooth 21, with an additional tube placed on this tooth; 18 months of treatment.
Figure 20
Figure 20
Palatal button on tooth 23 for cross elastic to assist in its vestibularization; 18 months of treatment.
Figure 21
Figure 21
Progressive repositioning of the bracket to aid in extrusion and derotation of the canine; 20 months of treatment.
Figure 22
Figure 22
Final adjustments with a button on tooth 22 for vertical recovery and cross elastics for stabilization; 24 months of treatment.
Figure 23
Figure 23
Canine 23 properly positioned in the arch in occlusion; 30 months of treatment.
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References

    1. Dachi S.F., Howell F.V. A Survey of 3,874 Routine Full-Mouth Radiographs. I. A Study of Retained Roots and Teeth. Oral Surg. Oral Med. Oral Pathol. 1961;14:916–924. doi: 10.1016/0030-4220(61)90003-2. - DOI - PubMed
    1. Miranda Pedro F.L., Bandéca M.C., Ricci Volpato L.E., Corrêa Marques A.T., Borba A.M., De Musis C.R., Borges Á.H. Prevalence of Impacted Teeth in a Brazilian Subpopulation. J. Contemp. Dent. Pract. 2014;15:209–213. doi: 10.5005/JP-JOURNALS-10024-1516. - DOI - PubMed
    1. Bishara S.E., Ortho D. Impacted Maxillary Canines: A Review. Am. J. Orthod. Dentofac. Orthop. 1992;101:159–171. doi: 10.1016/0889-5406(92)70008-X. - DOI - PubMed
    1. Miresmaeili A., Shokri A., Salemi F., Dehghani F., Shahidi-Zandi V., Rad R., Shahdoost M. Morphology of Maxilla in Patients with Palatally Displaced Canines. Int. Orthod. 2019;17:130–135. doi: 10.1016/j.ortho.2019.01.012. - DOI - PubMed
    1. Becker A., Chaushu S., Jerusalem I. Etiology of Maxillary Canine Impaction: A Review. Am. J. Orthod. Dentofac. Orthop. 2015;148:557–567. doi: 10.1016/j.ajodo.2015.06.013. - DOI - PubMed

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