A Finite Element Analysis for Mandibular Whole Arch Distalization According to Different Lengths of Retraction Hooks
Objectives: To compare the differences in displacement patterns and stress distribution in the periodontal ligament of whole mandibular dentition between distalization force vectors corresponding to retraction hooks of different lengths.
Methods: A cone beam computed tomography image of one 18-year-old female patient with Class III malocclusion was used to construct a finite element model. To simulate the whole arch distalization mechanics, a force of 200 g was applied to the miniscrews in the lower jaw using 1-, 3-, 6-, 9- and 12-mm retraction hooks. The displacement patterns of the teeth and the stress distribution in the periodontal ligament were analyzed on the x-, y-, and z-axes.
Results: At the retraction hook length of 6 mm, the incisors showed approximate bodily movement, the premolars showed slight extrusion, and the second molars showed slight intrusion. The von Mises stress in almost distalization patterns was highly distributed in the periodontal ligament of the teeth adjacent to the retraction hooks, especially when using hooks longer than 3 mm.
Conclusions: The 6-mm retraction hooks, used in conjunction with miniscrews on the mandibular buccal shelf area, caused mandibular dentition to move along the occlusal plane with minimal undesirable movement. The stress was highly distributed in the periodontal ligament of the teeth adjacent to the retraction hooks when hook length longer than 3 mm.
1. Proffit WR, Fields HW, Larson B, Sarver DM. Contemporary orthodontics. 6th ed. St. Louis, Mo: Elsevier Health Sciences; 2019.
2. Kuroda S, Tanaka E. Application of temporary anchorage devices for the treatment of adult Class III malocclusions. Semin Orthod. 2011;17(2):91-7.
3. Sung EH, Kim SJ, Chun YS, Park YC, Yu HS, Lee KJ. Distalization pattern of whole maxillary dentition according to force application points. Korean J Orthod. 2015;45(1):20-8.
4. Oh YH, Park HS, Kwon TG. Treatment effects of microimplant-aided sliding mechanics on distal retraction of posterior teeth. Am J Orthod Dentofac. 2011;139(4):470-81.
5. Jing Y, Han X, Guo Y, Li J, Bai D. Nonsurgical correction of a Class III malocclusion in an adult by miniscrew-assisted mandibular dentition distalization. Am J Orthod Dentofac. 2013;143(6):877-87.
6. Poletti L, Silvera AA, Ghislanzoni LTH. Dentoalveolar class III treatment using retromolar miniscrew anchorage. Prog Orthod. 2013;14(1):7.
7. Tai K, Park JH, Tatamiya M, Kojima Y. Distal movement of the mandibular dentition with temporary skeletal anchorage devices to correct a Class III malocclusion. Am J Orthod Dentofac. 2013;144(5):715-25.
8. Suh HY, Lee SJ, Park HS. Use of mini-implants to avoid maxillary surgery for Class III mandibular prognathic patient: a long-term post-retention case. Korean J Orthod. 2014;44(6):342-9.
9. Shih I, Lin J, Roberts W. Conservative correction of severe skeletal Class III open bite: 3 force vectors to reverse the dysplasia by retracting and rotating the entire lower arch. Int J Orthod Implantol. 2015;38:4-18.
10. Kuroda S, Sugawara Y, Deguchi T, Kyung HM, Takano-Yamamoto T. Clinical use of miniscrew implants as orthodontic anchorage: success rates and postoperative discomfort. Am J Orthod Dentofac. 2007;131(1):9-15.
11. Burstone CJ, Choy K. The biomechanical foundation of clinical orthodontics. Hanover Park: Quintessence Publishing; 2015.
12. Nanda R, Tosun YS. Biomechanics in orthodontics principle and practice. Hanover Park: Quintessence Publishing; 2010.
13. Konda P, Tarannum S. Basic principles of finite element method and its applications in orthodontics. J Pharm Biomed Sci. 2012;16(11):1-4.
14. Knop L, Gandini LG, Shintcovsk RL, Gandini MREAS. Scientific use of the finite element method in Orthodontics. Dental Press J Orthod. 2015;20:119-25.
15. Sung SJ, Jang GW, Chun YS, Moon YS. Effective en-masse retraction design with orthodontic mini-implant anchorage: A finite element analysis. Am J Orthod Dentofac. 2010;137(5):648-57.
16. Song JW, Lim JK, Lee KJ, Sung SJ, Chun YS, Mo SS. Finite element analysis of maxillary incisor displacement during en-masse retraction according to orthodontic mini-implant position. Korean J Orthod. 2016;46(4):242-52.
17. 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 Dentofac. 2012;142(4):501-8.
18. Caballero GM, de Carvalho Filho OA, Hargreaves BO, de Araújo Brito HH, Junior PAAM, Oliveira DD. Mandibular canine intrusion with the segmented arch technique: a finite element method study. Am J Orthod Dentofac. 2015;147(6):691-7.
19. Shah R, Sowmya N, Mehta D. Prevalence of gingival biotype and its relationship to clinical parameters. Contemp Clin Dent. 2015;6(Suppl1):167-71.
20. Kim YB, Bayome M, Park JH, Lim HJ, Mo SS, Lee NK, et al. Displacement of mandibular dentition during total arch distalization according to locations and types of TSADs: 3D Finite element analysis. Orthod Craniofac Res. 2019;22(1):46-52.
21. Nucera R, Lo Giudice A, Bellocchio AM, Spinuzza P, Caprioglio A, Perillo L, et al. Bone and cortical bone thickness of mandibular buccal shelf for mini-screw insertion in adults. Angle Orthod. 2017;87(5):745-51.