Magnitude of Force for Intrusion of Six Maxillary Anterior Teeth Using Mini-screw Anchorage: A Finite Element Study
Objectives: To evaluate the greatest magnitude of force that did not create the pressure in the periodontal ligament (PDL) exceeding the capillary hydrostatic pressure (0.0047 MPa) for the intrusion of six maxillary anterior teeth using two patterns of mini-screw anchorage, analyzed by the finite element method.
Methods: A finite element (FE) model of six maxillary anterior teeth with PDL and alveolar bone was constructed. In anchorage pattern 1, one mini-screw was placed between the central incisors with force applied to the arch wire between the central incisors towards the mini-screw. In anchorage pattern 2, used two mini-screws were placed between the lateral incisors and canines, left and right with force applied to the arch wire between the central and lateral incisors in an oblique direction towards the mini-screws. The pressure in PDL was analyzed.
Results: The greatest magnitude of force for the intrusion of six maxillary anterior teeth, that did not create the pressure in PDL exceeding the capillary hydrostatic pressure (0.0047 MPa) in anchorage pattern 1 was 16 g, and in anchorage pattern 2 was 47 g in total, or 23.5 g per each side. The greatest magnitude of force for the intrusion of the six maxillary anterior teeth in anchorage pattern 2 (47 g) was greater than that in anchorage pattern 1 (16 g). The greatest pressure area in anchorage pattern 1 was at the apex of the palatal side of PDL of the right central incisor, while the greatest pressure area in anchorage pattern 2 was at the apex of the palatal side of PDL of the right lateral incisor.
Conclusions: The greatest magnitude of force for the intrusion of the six maxillary anterior teeth that did not create the pressure in the periodontal ligament (PDL) exceeding the capillary hydrostatic pressure in anchorage pattern 1 was 16 g. In anchorage pattern 2, the greatest magnitude of force was 47 g in total or 23.5 g per each side.
1. Kanomi R. Mini-implant for orthodontic anchorage. J Clin Orthod 1997; 31: 763-767.
2. Proffit WR, Fields HW, Sarver DM. The biologic basis of orthodontic therapy. Contemporary Orthodontics. 5th ed. St. Louis, MO, USA: Elsevier/Mosby; 2013: 286-287.
3. Han G, Huang S, Von den Hoff JW, Zeng X, Kuijpers-Jagtman AM. Root resorption after orthodontic intrusion and extrusion: an intraindividual study. Angle Orthod 2005; 75: 912-918.
4. Aras I, Tuncer AV. Comparison of anterior and posterior mini-implant-assisted maxillary incisor intrusion: Root resorption and treatment efficiency. Angle Orthod 2016; 86: 746-752.
5. Schwarz AM. Tissue changes incidental to orthodontic tooth movement. Int J Orthod Oral Surg Radiogr 1932; 18: 331-352.
6. Dorow C, Sander FG. Development of a model for the simulation of orthodontic load on lower first premolars using the finite element method. J Orofac Orthop 2005; 66: 208-218.
7. Hohmann A, et al. Correspondences of hydrostatic pressure in periodontal ligament with regions of root resorption: A clinical and a finite element study of the same human teeth. Comput Methods Programs Biomed 2009; 93: 155-161.
8. Burstone CR. Deep overbite correction by intrusion. Am J Orthod 1977; 72: 1-22.
9. Gianelly AA, Goldman HM. Biologic basis of orthodontics: Lea & Febiger; 1971: 64.
10. Rubin C, Krishnamurthy N, Capilouto E, Yi H. Stress analysis of the human tooth using a three-dimensional finite element model. J Dent Res 1983; 62: 82-86.
11. Kojima Y, Kawamura J, Fukui H. Finite element analysis of the effect of force directions on tooth movement in extraction space closure with miniscrew sliding mechanics. Am J Orthod Dentofacial Orthop 2012; 142: 501-508.
12. Caballero GM, Carvalho Filho OA, Hargreaves BO, Brito HH, Magalhaes Jr PA, Oliveira DD. Mandibular canine intrusion with the segmented arch technique: A finite element method study. Am J Orthod Dentofacial Orthop 2015; 147: 691-697.
13. Choi JH, Yu HS, Lee KJ, Park YC. Three-dimensional evaluation of maxillary anterior alveolar bone for optimal placement of miniscrew implants. Korean J Orthod 2014; 44: 54-61.
14. Cifter M, Sarac M. Maxillary posterior intrusion mechanics with mini-implant anchorage evaluated with the finite element method. Am J Orthod Dentofacial Orthop 2011; 140: e233-e241.
15. Huang H, Tang W, Yan B, Wu B. mechanical responses of periodontal ligament under a realistic orthodontic loading. Procedia Eng 2012; 31: 828-833.
16. Weltman B, Vig KW, Fields HW, Shanker S, Kaizar EE. Root resorption associated with orthodontic tooth movement: a systematic review. Am J Orthod Dentofacial Orthop 2010; 137: 462-476; discussion 412A.
17. Killiany DM. Root resorption caused by orthodontic treatment: an evidence-based review of literature. Semin Orthod 1999; 5: 128-133.
18. Brezniak N, Wasserstein A. Orthodontically induced inflammatory root resorption. Part I: the basic science aspects. Angle Orthod 2002; 72: 175-179.
19. Harris DA, Jones AS, Darendeliler MA. Physical properties of root cementum: part 8. volumetric analysis of root resorption craters after application of controlled intrusive light and heavy orthodontic forces: a microcomputed tomography scan study. Am J Orthod Dentofacial Orthop 2006; 130: 639-647.
20. Yu JH, Shu KW, Tsai MT, Hsu JT, Chang HW, Tung KL. A cone-beam computed tomography study of orthodontic apical root resorption. J Dent Sci 2013; 8: 74-79.
21. Salehi P, Gerami A, Najafi A, Torkan S. Evaluating stress distribution pattern in periodontal ligament of maxillary incisors during intrusion assessed by the finite element method. J Dent (Shiraz) 2015; 16:314-322.
22. Sakdakornkul S, Patanaporn V, Rungsiyakul C. Intrusion of six maxillary anterior teeth using mini-screw anchorage: a finite element study. CM Dent J 2019; 40(2): 51-63.
23. Toms SR, Eberhardt AW. A nonlinear finite element analysis of the periodontal ligament under orthodontic tooth loading. Am J Orthod Dentofacial Orthop 2003; 123:657-665.
24. Baumgaertel S, Hans MG. Buccal cortical bone thickness for mini-implant placement. Am J Orthod Dentofacial Orthop 2009; 136: 230-235.
25. Toms SR, Lemons JE, Bartolucci AA, Eberhardt AW. Nonlinear stress-strain behavior of periodontal ligament under orthodontic loading. Am J Orthod Dentofacial Orthop 2002; 122: 174-179.
26. Ralph WJ. The in vitro rupture of human periodontal ligament. J Biomech 1980; 13: 369-373.
27. Melsen B, Agerbaek N, Markenstam G. Intrusion of incisors in adult patients with marginal bone loss. Am J Orthod Dentofacial Orthop 1989; 96: 232-241.