Korean J Orthod.  2020 Jan;50(1):26-32. 10.4041/kjod.2020.50.1.26.

Comparison of inclination and vertical changes between single-wire and double-wire retraction techniques in lingual orthodontics

• Hung BQ
• Hong M
• Yu W
• Kyung HM

• KMID: 2468638
• DOI: http://doi.org/10.4041/kjod.2020.50.1.26

Abstract

OBJECTIVE
The Heat Induction Typodont System (HITS), used in some recent studies, has a distinct advantage over previous tooth movement simulation methods. This study aimed to compare inclination and vertical changes between the single-wire and double-wire techniques during en masse retraction with different lengths of lever arms in lingual orthodontics using an upgraded version of the HITS.
METHODS
Duet lingual brackets, which have two main slots, were used in this study. Forty samples were divided into four groups according to the length of the lever arm (3-mm or 6-mm hook) and the retraction wire (single-wire or double-wire). Four millimeters of en masse retraction was performed using lingual appliances. Thereafter, 3-dimensional-scanned images of the typodont were analyzed to measure inclination and vertical changes of the anterior teeth.
RESULTS
Incisor inclination presented more changes in the single-wire groups than in the double-wire groups. However, canine inclination did not differ between these groups. Regarding vertical changes, only the lateral incisors in the single-wire groups presented significantly larger values than did those in the double-wire groups. Combining the effect of hook lengths, among the four groups, the single-wire group with the 3-mm hook had the highest value, while the double-wire group with the 6-mm hook showed the least decrease in crown inclination and extrusion.
CONCLUSIONS
The double-wire technique with an extended lever arm provided advantages over the single-wire technique with the same lever arm length in preventing torque loss and extrusion of the anterior teeth during en masse retraction in lingual orthodontics.

Keyword

En masse retraction; Lingual; Heat Induction Typodont; Tooth movement

MeSH Terms

Arm
Crowns
Hot Temperature
Incisor
Orthodontics*
Tooth
Tooth Movement
Torque

Figure

• 

  Figure 1 A, The maxillary typodont is composed of anterior metal teeth and posterior resin teeth, and the first premolars were extracted. B, The typodont is placed in the Heat Induction Typodont System machine. C, A Duet bracket has two main slots, one occlusal slot (grey circle) and one lingual slot (black circle).

• 

  Figure 2 Illustrations of the four groups used in this study. In the double wire groups, an auxiliary wire is placed only in the six anterior brackets. Group 1, Single wire with a 3-mm hook; Group 2, single wire with a 6-mm hook; Group 3, double wire with a 3-mm hook; Group 4, double wire with a 6-mm hook.

• 

  Figure 3 A, Measurement of vertical position changes by the perpendicular distance of the tip of the teeth between T1 and T2, referenced to the original occlusal plane. B, Measurement of inclination changes by the difference between T1 and T2 inclination angle formed by the long axis of the tooth and the original occlusal plane. T1, Before incisor retraction (gray); T2, after 4-mm space closure (purple).

Reference

1. Lim SM, Hong RK. The Tandem Archwire technique in lingual orthodontics. J Clin Orthod. 2013; 47:232–240. quiz 267.

2. Lombardo L, Scuzzo G, Arreghini A, Gorgun O, Ortan YO, Siciliani G. 3D FEM comparison of lingual and labial orthodontics in en masse retraction. Prog Orthod. 2014; 15:38.

3. Hong RK, Heo JM, Ha YK. Lever-arm and mini-implant system for anterior torque control during retraction in lingual orthodontic treatment. Angle Orthod. 2005; 75:129–141.

4. Hong RK, Sohn HW. Update on the Fujita lingual bracket. J Clin Orthod. 1999; 33:136–142.

5. Beckwith FR, Ackerman RJ Jr, Cobb CM, Tira DE. An evaluation of factors affecting duration of orthodontic treatment. Am J Orthod Dentofacial Orthop. 1999; 115:439–447.

6. Meikle MC. Guest editorial: what do prospective randomized clinical trials tell us about the treatment of class II malocclusions? A personal viewpoint. Eur J Orthod. 2005; 27:105–114.

7. Liang W, Rong Q, Lin J, Xu B. Torque control of the maxillary incisors in lingual and labial orthodontics: a 3-dimensional finite element analysis. Am J Orthod Dentofacial Orthop. 2009; 135:316–322.

8. Rhee JN, Chun YS, Row J. A comparison between friction and frictionless mechanics with a new typodont simulation system. Am J Orthod Dentofacial Orthop. 2001; 119:292–299.

9. Kyung HM, Kim JY, Kyung IK. Heat Induction Typodont System® (HITS) for simulating orthodontic tooth movement. Clin J Korean Assoc Orthod. 2013; 3:177–179.

10. Kim JY, Yu WJ, Koteswaracc PNK, Kyung HM. Effects of bracket slot size during en-masse retraction of the six maxillary anterior teeth using an induction-heating typodont simulation system. Korean J Orthod. 2017; 47:158–166.

11. Kyung HM, Park HS, Bae SM, Sung JH, Kim IB. The lingual plain-wire system with micro-implant anchorage. J Clin Orthod. 2004; 38:388–395.

12. Kim T, Bae G, Cho J. New indirect bonding method for lingual orthodontics. J Clin Orthod. 2000; 34:348–350.

13. Lee JS, Park H, Kyung HM. Micro-implant anchorage for lingual treatment of a skeletal class II malocclusion. J Clin Orthod. 2001; 35:643–647.

14. Isaacson RJ, Lindauer SJ, Rubenstein LK. Moments with the edgewise appliance: incisor torque control. Am J Orthod Dentofacial Orthop. 1993; 103:428–438.

15. Sifakakis I, Pandis N, Makou M, Eliades T, Katsaros C, Bourauel C. A comparative assessment of torque generated by lingual and conventional brackets. Eur J Orthod. 2013; 35:375–380.

16. Jang HJ, Roh WJ, Joo BH, Park KH, Kim SJ, Park YG. Locating the center of resistance of maxillary anterior teeth retracted by Double J Retractor with palatal miniscrews. Angle Orthod. 2010; 80:1023–1028.

17. Kim KH, Lee KJ, Cha JY, Park YC. Finite element analysis of effectiveness of lever arm in lingual sliding mechanics. Korean J Orthod. 2011; 41:324–336.