Korean J Orthod.  2025 May;55(3):183-192. 10.4041/kjod24.201.

En masse maxillary dentition distalization with clear aligners using infrazygomatic mini-implants: A finite element study

• Nassar N
• Geramy A
• Kmeid R
• Nassif NB
• Medawar L
• Sayegh P
• Bouserhal J

• KMID: 2568341
• DOI: http://doi.org/10.4041/kjod24.201

Abstract

Objective
Considering the success of infrazygomatic mini-implants in conjunction with traditional braces, this study aimed to evaluate the efficacy of infrazygomatic mini-implants in en masse maxillary distalization utilizing clear aligner therapy.
Methods
In a three-dimensional finite element study, we evaluated the en masse maxillary dental distalization through the use of infrazygomatic mini-implants equipped with varying force-application arm lengths (0 mm, 4 mm, and 8 mm). Vertical, sagittal, and horizontal displacements were quantified.
Results
Intrusion was observed in the incisors at all force application arm lengths (0 mm, 4 mm, and 8 mm), with similar sagittal displacement tendencies and labial crown tipping. Among all maxillary teeth, only the canine exhibited distalization of both the crown and root. Distalization of the posterior teeth was achieved, with the greatest magnitude of distalization occurring at the 0-mm force application arm length, which was characterized by minimal tipping and reduced vertical movements compared to the other force application arm lengths.
Conclusions
The findings indicate that infrazygomatic mini-implants represent a viable approach for facilitating targeted tooth movement in clear aligners across various force-application arm lengths. These results may inform orthodontic treatment strategies in non-extraction cases.

Keyword

Finite element method; Distalization; Orthodontic mini-implants; Aligners

Figure

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  Figure 1 Meshed three-dimensional models of the A, Aligner without hook; B, Model 1 with aligner and IZ mini-implant at 0 mm; C, Model 2 with aligner and IZ mini-implant at 4 mm; D, Model 3 with aligner and IZ mini-implant at 8 mm. IZ, infrazygomatic.

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  Figure 2 Vertical displacement in the buccal view for A, Model 1; B, Model 2; C, Model 3.

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  Figure 3 Vertical displacement in the three models. The numbers denote the maxillary teeth: 1, central incisor; 2, lateral incisor; 3, canine; 4, first premolar; 5, second premolar; 6, first molar; 7, second molar.

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  Figure 4 Horizontal displacement in the three models. The numbers denote the maxillary teeth: 4, first premolars; 5, second premolars; 6, first molars; 7, second molars.

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  Figure 5 Horizontal displacement in the occlusal view for A, Model 1; B, Model 2; C, Model 3.

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  Figure 6 Sagittal displacement in the three models. The numbers denote the maxillary teeth: 1, central incisor; 2, lateral incisor; 3, canine; 4, first premolar; 5, second premolar; 6, first molar; 7, second molar.

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  Figure 7 Sagittal displacement of the maxillary teeth across the three models.

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