JC laceback ppt orthodontics and dentofacial orthopaedic

Laceback in orthodontic

1. Presented By – Dr. Shivam Singh Dept Of Orthodontics and Dentofacial Orthopaedics Terna Dental College And Hospital Guide – Dr. Shailesh Shenava Objective To evaluate the effects of laceback ligatures on the anteroposterior and vertical position of lower incisors and the mesial position of the lower first molars R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

2. INTRODUCTION One of the major disadvantages of incorporating second order values into the pre-adjusted edgewise bracket system, was it created stress on anchorage in the initial stages of treatment . McLaughlin and Bennett argued that the tip incorporated into the incisor and canine brackets increased the tendency for the labial segments to tip forward, and that this was more pronounced in the upper arch where bracket tip was greater . First described by McLaughlin and Bennett, laceback ligatures are constructed of either 0.009 or 0.010 inch soft stainless steel tied in a figure of 8 from the most distally incorporated molar to the canine bracket. Benefits of lacebacks Prevention of labial segment proclination Canine distalization without tipping protection from masticatory forces for light aligning archwires across the extraction spaces. R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

3. Robinson in a prospective study found a 2.47 mm difference in the lower incisor antero -posterior position between cases treated with or without lacebacks . Usmani et al . published the first randomized clinical controlled trial on the effectiveness of lacebacks . They also examined the effect of pretreatment distal angulations of the canine on the effectiveness of lacebacks . They found a mean retroclination of the upper incisors in the laceback group of 0.5 mm with a mean proclination in the non- laceback group of 0.36 mm. Space creation T he canines distalized into the extraction spaces creating space with no influence on incisor proclination ; T he incisors proclined to create space for their alignment S pace was actively created using traction to the canine or active push-coil, within the labial segment to provide space for full incisor alignment R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

4. Aim T o evaluate the antero -posterior changes in lower labial segment position that occur during leveling and aligning with the pre-adjusted edgewise appliance T o evaluate the changes in antero -posterior position of the lower labial segment as a consequence of lacebacks used during leveling and aligning with the preadjusted edgewise appliance T o assess any changes in the vertical position of the lower labial under the influence of laceback ligatures T o assess the influence of lacebacks on the lower first molar R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

5. Materials And Methods 62 participants were enrolled on the study, 30 (12 male, 18 female) in the laceback group and 32 (14 male, 18 female) non- laceback controls. Each patient was randomly assigned to one of the groups by the toss of a coin. The majority of participants had either a Class I or a mild Class II division 1 incisor relationships with crowding (Class I; Class II division 1; Class II division 2; Class III , with a uniform distribution between experimental and control groups ). Patient Selection Criteria : M alocclusion requiring the extraction of all first premolars. N o previous orthodontic treatment. L ateral cephalometric radiographs to have been taken of the patient within the previous 12 months at the start of treatment. R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

6. Treatment Protocol All participants were treated by the same operator (SP ). All first premolars were extracted approximately 1– 2 weeks prior to the fitting of appliances. Upper and lower fixed appliances using 3 M Unitek Dyna Lock pre-adjusted edgewise brackets from the non-extraction series (Andrews s values for tip and torque using a 0.022 inch slot ). The plan of treatment for the study was to follow each patient to the point at which leveling and aligning of the buccal segments had been achieved with a 0.018 inch stainless steel arch wire; it was agreed that this should be following six weeks with the 0.018 inch stainless steel arch wire in situ. R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

7. All teeth from first molar to first molar had attachments placed. Severe vertical or rotational discrepancies between adjacent teeth were partially ligated at the first visit. Extremely crowded and displaced teeth in the labial segment were passively tied to the arch wire and were not engaged until sufficient space was available. Each patient went through the same arch wire sequence of 0.014 inch NiTi , 0.016 inch NiTi , 0.018 inch NiTi and 0.018 inch stainless steel. Participants were seen routinely at 6-week intervals . 5. The arch wire was cut distal to the first molar tube and no cinching of the arch wire took place. 6. No bite planes, lingual arches, inter maxillary elastics or headgear direct to the lower arch was used during the study period. R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

8. 7. Laceback ligatures were passively tied from the first molar tube to the canine bracket on both sides in the experimental group and tightened to take up any apparent reduction in tension in the laceback at routine visits. 8. Records of each case included standardized lateral cephalometric radiographs. Study models were taken immediately after the placement of fixed appliances (T1) and again following leveling of the canine with a 0.018 inch stainless-steel arch wire (T2). The Ethics committee accepted the second radiograph as part of both validation of clinical techniques and to support information to determine how to close the extraction space; either by maintaining the position of the labial segments and allowing the buccal segments to move mesially or by retraction of the labial segment . Due to the time the participants were on the waiting list, T2 radiographs were all taken a minimum of 14 months from T1 radiographs. R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

9. Landmark Identification The lower right first molar (46) would be used to study the mesial molar movement and the lower right central incisor (41) would be used to study the anteroposterior movement of the lower labial segment . A method utilizing identification markers constructed of 0.021x025 inch stainless-steel wire was used placed in the bracket of the incisor and molar tube. 7 degree to SN was used as a horizontal reference line and a y-axis dropped perpendicular to this through Sella. Linear measurements to the 4 cephalometric points were recorded perpendicular to this y-axis to assess antero -posterior changes.

10. R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

11. R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

12. In both groups the lower incisors retroclined during the time between T1 and T2 (experimental 20.53 +/- 1.9 mm, control 20.44 +/- 1.29 mm) and there was no statistical significance between the two groups . The lower incisors extruded in both groups; 0.47 +/- 0.98 mm in the experimental group and 0.44 +/- 0.87 mm in the control group. This difference showed no statistical difference between the groups. The lower first molars showed 0.83 mm greater mesial movement in the experimental group. Labial segment crowding decreased in both groups (Experimental 23 +/- 1.6 mm, control 22.67 +/- 2.28 mm). Arch length decreased in both groups (experimental 22.08 +/- 2.82 mm, control 22.9 +/- 3.06 mm). R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

13. This demonstrates that in this study, rather than proclining during the leveling stage of treatment the lower incisors retroclined slightly . This result is in contrast with the observations of Meyer and Nelson and McLaughlin and Bennett , who suggested that the pre-adjusted edgewise appliance proclined the labial segments and compromised anchorage during the initial stages of treatment . Rather than proclining , the lower labial segment in the control group in this study showed a mean nonsignificant retroclination of 0.44 mm while experimental group showed 0.53mm. With the results of this report and also supported by Usmani et al . the validity of lacebacks as an adjunct for the straight wire technique has to be questioned . Further work is required to examine the levels of plaque accumulation with and without lacebacks as the possibility that the appliance is a plaque retention factor is clear Discussion R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

14. Conclusion In first premolar extraction cases, the lower labial segment does not procline during the leveling stage with the pre-adjusted edgewise appliance. The use of laceback ligatures conveys no statistical or clinical difference in the anteroposterior or vertical position of the lower labial segment or in the relief of labial segment crowding. The use of laceback ligatures creates a statistically and clinically significant increase in the loss of posterior anchorage, through mesial movement of the lower first molars. R. Irvine and S. Power, F. McDonald, The effectiveness of laceback ligatures: A randomized controlled clinical trial , Journal of Orthodontics, Vol. 31, 2004

15. The initial phase of orthodontic treatment is directed at orthodontic alignment in the horizontal and vertical plane involving arch alignment and rotational control. Lacebacks , typically formed from 0.09 ” to 0.1 ” stainless steel wire spanning the first molars to canines, have been devised as a mechanism to control the antero -posterior position of the incisors during the initial alignment phase by controlling the angulation of the canine teeth . Disadvantages of laceback use may include loss of anchorage posteriorly manifesting as mesial migration and tipping of first permanent molars , potential for plaque stagnation , and limited additional chairside time and complexity. P. Fleming, Ama Johal , Nikoloas Pandis , The effectiveness of laceback ligatures during initial orthodontic alignment: A systematic review and met-analysis, Journal of orthodontics, 2012.

16. The incisors were found to move posteriorly in the laceback group in each study (0.5 – 1.04 mm). Similarly, retraction of the incisors was also found in the study by Irvine et al. (2004) in the participants treated without lacebacks , although the amount of posterior movement was minimal (0.44 ± 1.29 mm ). However, without use of lacebacks , anchorage loss manifest as advancement of the incisors was reported in the other trials ( Robinson, 1989 ; Usmani et al. , 2002 ). Similarly, laceback use was associated with greater mesial displacement of the molars during arch alignment in two studies ( Robinson, 1989 ; Irvine et al. , 2004 ). Following statistical amalgamation of these studies, use of lacebacks was associated with 0.5 mm greater posterior movement of the incisors during alignment . L ittle difference was observed between laceback (LB) and non-LB groups with respect to anchorage loss with 0.45 mm more mesial molar movement in the LB group. Results P. Fleming, Ama Johal , Nikoloas Pandis , The effectiveness of laceback ligatures during initial orthodontic alignment: A systematic review and met-analysis, Journal of orthodontics, 2012.

17. Conclusion On the basis of this review and meta-analysis, there is little evidence to support the use of lacebacks during orthodontic alignment . In particular, use of lacebacks had an insignificant effect on the antero -posterior position of the incisors during orthodontic alignment. Similarly, there was a minor difference in molar anchorage loss (0.45mm) with use of laceback ligatures, which is of little clinical relevance. In addition, while slightly more incisor retraction occurred during alignment in conjunction with lacebacks (0.5 mm ). P. Fleming, Ama Johal , Nikoloas Pandis , The effectiveness of laceback ligatures during initial orthodontic alignment: A systematic review and met-analysis, Journal of orthodontics, 2012.

18. In an attempt to prevent anterior teeth from tipping forward during the initial stages of orthodontic treatment because of the tip built into the anterior preadjusted brackets, McLaughlin et al . recommended the use of the lacebacks , which are figure-eight 0.010-inch ligature wires, from the most distally banded molar to the canine bracket in each quadrant. Active lacebacks may be especially used in premolar extraction cases to provide distal cuspid movement, opening space for the alignment of crowded incisors. Lacebacks may also be indicated in their passive form in premolar extraction cases to prevent canine mesial movement or in non-extraction cases. Introduction

19. Materials and methods Twenty-three subjects (16 females and 7 males) aged between 12 and 18 years (mean age = 15 years and 5 months) were enrolled in this study. All subjects had Class I or Class II malocclusion and orthodontic treatment was planned with extractions of maxillary first premolars. The sample was divided in 2 groups: Group 1, with 14 subjects with active lacebacks and Group 2, with 9 subjects with passive lacebacks . To avoid superposition of nickel-titanium archwires ’ effects (5,6), the leveling phase was performed using stainless steel archwires only (0.014, 0.016, 0.018, 0.020 and 0.019x0.025- inch). The leveling phase was started with 0.014-inch and 0.016-inch archwires adapted passively to bracket slots, introducing first and second order bends that were progressively undone during the appointments. No bends were introduced in the subsequent archwires . In Group 1, lacebacks were reactivated monthly until the canines were retracted, allowing incisors alignment . In Group 2, lacebacks were installed passively (no retraction force over canine brackets) and were changed just in case of wire fractures. Moresca et.al , Effects of active and passive lacebacks on antero -posterior position of maxillary first molars and central incisors , Brazil Dental Journal, 2012.

20. Results Moresca et.al , Effects of active and passive lacebacks on antero -posterior position of maxillary first molars and central incisors , Brazil Dental Journal, 2012.

21. Conclusion A ctive and passive lacebacks need more specific definitions. Despite lacebacks having been found to be an effective method to retract canines, the force produced by active lacebacks can produce anchorage loss that must be considered in treatment planning when its use is indicated . Clinicians should also consider using 0.008- inch ligature wire in laceback placement. Active laceback produced a mesial movement of the maxillary first molars that can be understood as anchorage loss during the leveling phase, and that passive laceback did not affect the position of these teeth . Also, active and passive lacebacks were effective in preventing incisors’ proclination . Moresca et.al , Effects of active and passive lacebacks on antero -posterior position of maxillary first molars and central incisors , Brazil Dental Journal, 2012.

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