Turkish Journal of Orthodontics
Original Article
Evaluation of Stress Pattern Caused by Mini-Implant in Mandibular Alveolar Bone with Different Angulations and Retraction Forces: A Three-Dimensional Finite Element Study

Evaluation of Stress Pattern Caused by Mini-Implant in Mandibular Alveolar Bone with Different Angulations and Retraction Forces: A Three-Dimensional Finite Element Study

1.

Private Practice, New Delhi, India

2.

Department of Dentistry, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India

3.

Department of Orthodontics, KD Dental College, Mathura, Uttar Pradesh, India

4.

Department of Orthodontics, Vyas Dental College & Hospital, Jodhpur, Rajasthan, India

5.

Department of Orthodontics, King George Medical University Lucknow, Uttar Pradesh, India

Turk J Orthod 2020; 33: 150-156
DOI: 10.5152/TurkJOrthod.2020.19109
Read: 405 Downloads: 196 Published: 18 August 2020

Objective: The objective of the study was to evaluate the stress pattern in cortical and cancellous bones, periodontal ligament, and in the implant itself when a mini-implant (MI) is inserted in the inter-radicular space between mandibular first molar and second premolar at various angulations and different retraction forces.

Methods: Finite element study was conducted with MI insertion at 30°, 45°, 60°, 75°, and 90° angulations in the mandibular posterior region (between second premolar and first molar). At these angulations, horizontal forces of 150, 200, and 250 g were applied to the middle of the MI head. von Mises stress values were then evaluated using the ANSYS software.

Results: Highest von Mises stress values were detected in the MI itself, followed by cortical bone, cancellous bone, and periodontal ligament. The von Mises stress values in cortical bone were highest at  30° angulation and lowest at 90° angulation. In the cancellous bone, the stress value was found to be maximum at 90°. The von Mises stress values in the MI were lowest at 90°. In all four structures, as the load increased from 150 to 250 g, the von Mises stress values increased.

Conclusion: The von Mises stress values in the cortical bone, MI, and periodontal ligament were found to be lowest at 90°. Placement of the MI at 90° appears to be an ideal angulation when applied with a horizontal load. Force range used is within clinically recommended levels; however, the increase in load causes an increase in the stress values.

Cite this article as: Sidhu M, Chugh VK, Dmello K, Mehta A, Chugh A, Tandon P. Evaluation of Stress Pattern Caused by Mini-Implant in Mandibular Alveolar Bone with Different Angulations and Retraction Forces: A Three-Dimensional Finite Element Study. Turk J Orthod 2020; 33(3): 150-6.

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