International Journal of Medical and Dental Case Reports

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Pendulum appliance and K-loop combination for molar distalization: A case report
  IJMDCR
CASE REPORT
Pendulum appliance and K-loop combination for molar
distalization: A case report
Riddhi Bagaria, S. M. Laxmikanth
Department of Orthodontics and Dentofacial Orthopaedics, AECS Maaruti College of Dental Sciences and Research Centre, Bengaluru, Karnataka, India
Correspondence: Dr. Riddhi Bagaria, 32/1, Sarat Chatterjee Road, Near Chatterjee Hat Govt. Quarters, Belepole, Howrah - 711 104,West Bengal, India.
E-mail: redhuriddhi11@gmail.com
Received 20th August 2018;
Accepted 27th September 2018
doi: 10.15713/ins.ijmdcr.102
 
ABSTRACT
Most non-extraction Class II malocclusions are treated by extraoral and intraoral appliances for molar distalization. Extraoral traction is effective but depends on patient cooperation. This led to the use of intraoral appliances; however, they too have drawbacks such as molar tipping and loss of anchorage. In this case report, a 13-year-old patient with Class II malocclusion with good facial balance is treated non-extraction. The two quadrants were divided into pendulum only and pendulum K-loop combination to compare the amount of molar tipping and dentoalveolar changes on both sides. The left upper quadrant has Hilgers pendulum appliance (pendulum only). On the right side, pendulum was adjuncted buccally by Karla's K-loop appliance using split-mouth technique. It was concluded that Class I molar and canine relation was achieved faster on pendulum only side, though it presented with more distal molar tipping as compared to pendulum K-loop combination side which showed a controlled molar distalization.
Keywords: Class II treatment, Molar distalization, pendulum K-loop combination
How to cite the article: Laxmikanth SM. Pendulum appliance and K-loop combination for molar distalization: A case report. Int J Med Dent Case Rep 2018;5:1-4
 
 

Introduction

Angle's Class II malocclusion manifests with challenges to the orthodontists. One can no longer exclusively think about extraction line of the treatment because experiences have shown that indiscriminate extraction of teeth in some borderline cases makes the profile more concave. Non-extraction line of the treatment of Class II malocclusion differs in growing and adult patients.[1]

A common strategy to correct Class II malocclusion in growing patients, using non-extraction protocol, is to distalize the maxillary molars to achieve Class I molar relationship. Extraoral traction with headgear is one of the earliest and efficient methods to move molars distally, although they depend primarily on patient cooperation. This lead to the emergence of patient-friendly intraoral distalization appliances such as magnets, pendulum, NiTi coil springs, Jones jig, and distal jet.[2-5]

Among these, Hilgers pendulum appliance is widely used. However, it causes undesirable distal tipping of maxillary molars and loss of anterior anchorage during distalization.[3] K-loop, introduced in 1995 by Kalra,[6] developed more biomechanically efficient system to control molar tipping. Studies have shown that both these appliances have similar skeletal and dentoalveolar effects.[7] There is only one comparative study in the literature that evaluated the effects using pendulum appliance buccally supported with a K-loop and compared it with extraoral traction. It stated that distal tipping and anterior anchorage loss were significantly reduced using the combination of pendulum and K-loop appliance.[1]

 
Hence, in this case report, we used pendulum only and pendulum K-loop combination on two opposite sides in the same patient, same intraoral environment to compare the effectiveness of combining K-loop with pendulum appliance.

Treatment procedure

A 13-year-old patient reported with a chief complaint of irregularly placed upper teeth. On examination, she has mild skeletal Class II base with Angle's Class II malocclusion, average growth pattern with a negative VTO, deep overbite, moderate crowding in both jaws, and good facial balance with average nasolabial angle [Figure 1].

A non-extraction treatment plan was decided with distalization of maxillary molars to gain space for decrowding as well as correction of the molar and canine relation. The patient refused the use of headgear, thus the Hilgers pendulum appliance was chosen. To compare and control molar tipping, it was supported on one quadrant with a K-loop, fabricated with 0.017 × 0.025" titanium molybdenum alloy wire as described by Kalra.[6] The pendulum arm was made 2 mm longer on pendulum only side so similar distalization distance achieved on both sides [Figure 2].

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Riddhi and Laxmikanth Pendulum appliance and K-loop combination for molar distalization - A case report

After insertion of the appliances, the patient wasmonitored every 3 weeks and the appliances were activatedevery 1 month.

Treatment results

Significant distalization with super Class I molar relation wasachieved on pendulum only side within 11 weeks of the treatment.The pendulum K-loop combination side progressed slowly withcompletion of Class I relation in 15 weeks. However, it showedmore of bodily movement of molar, while the pendulum onlyside showed more of molar tipping and slight rotation of molarmesiobuccally.

The patient was bonded with MBT 0.022 appliance. In theupper arch, segmental bonding was done initially along withthe distalization appliances, to relieve anterior crowding. Afterdistalization, the appliances were removed on both sides and aNance palatal button was given for retention. Complete bondingof both the arches was done. Leveling and aligning followed byclosure of distalization spaces were done. Finishing and detailingwere done using NiTi archwires [Figure 3].

Pendulum appliance and K-loop combination for molar distalization: A case report
Figure 1: Pre-treatment extraoral and intraoral photographs

Pendulum appliance and K-loop combination for molar distalization: A case report
Figure 2: Appliances for molar distalization: Pendulum appliance,supported buccally by a K-loop (right quadrant)

 
Post-treatment radiographs [Figure 4] revealed good rootparallelism and the cephalometric values have remained more orless the same as pre-treatment values [Table 1].

Mandible has very slightly rotated forward. Comparison ofpre-treatment and post-treatment records reveals good estheticand functional result [Figures 5 and 6].

Discussion

Non-extraction treatment of Class II malocclusion requiresmaxillary molar distalization by means of extraoral or intraoralforces. Headgear traction has been undoubtedly proven efficient incorrection of skeletal Class II discrepancy; however, the dependenceon the patient cooperation and associated soft tissue injuries is ofconcern. A randomized review on molar distalization suggestedthat intraoral appliances are more effective than headgear.[7]

Pendulum appliance and K-loop combination for molar distalization: A case report
Figure 3: Post-treatment photographs

Pendulum appliance and K-loop combination for molar distalization: A case report
Figure 4: Comparison of pre- and post-treatment orthopantomogramand lateral cephalographs

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Riddhi and LaxmikanthPendulum appliance and K-loop combination for molar distalization - A case report

Table 1: Cephalometric data pre-treatment and post-treatment
Pendulum appliance and K-loop combination for molar distalization: A case report

Various intraoral appliances were introduced for molardistalization, but unfortunately, none can control molarmovement in all three dimensions. Kalra's K-loop wasintroduced for effective molar control and manipulation ofmoment-to-force ratio. It claimed to achieve bodily molarmovement with controlled tipping. However, a recentprospective comparative study has concluded similar skeletaland dentoalveolar effects of both pendulum appliance andK-loop.[8] In another study, the authors have found the use ofa pendulum appliance supported buccally by K-loop, overcamethe disadvantages of intraoral appliances, namely distal molartipping and loss of anchorage.[1]

In the present study, a combination of two intraoralappliances (pendulum and K-loop) was used and results werecompared to pendulum only appliance. Two quadrants of samepatient were chosen as a split-mouth technique. It was found thatthe dentoalveolar effects of both sides differed.

Molar distalization of 5.1 mm was achieved faster onpendulum only side, with molar moving into super Class I relationin 11 weeks. The side effects were more pronounced, with distaltipping of molar. Contrary to this, the combination of pendulumK-loop appliance progressed more bodily without molar tipping,with 4.7 mm of super Class I molar achieved in 15 weeks' time.Several studies have shown upper incisors protrusion duringdistalization with intraoral appliances; however, in the currentcase, no such effect was seen.

Conclusion

Until now, very few studies have been published in the literatureto substantiate the biomechanical effectiveness of K-loopappliance. It is technique sensitive and requires proper balancingof moment-to-force ratio and anti-rotation bends. Pendulumappliance provides palatal anchorage from its Nance button.These two appliances when combined together can overcomethe unwanted movements of each other, with consistency inforce delivery resulting in controlled molar distalization. Theauthors recommend further long-term investigations to confirmthese findings and the use of combination pendulum K-loopappliance.

 
Pendulum appliance and K-loop combination for molar distalization: A case report
Figure 5: Comparison of pre- and post-treatment records

Pendulum appliance and K-loop combination for molar distalization: A case report
Figure 6: Lateral cephalometric superimposition: Pre- (black) andpost-distalization (red)

References
  1. Acar AG, Gursoy S, Dincer M. Molar distalization with apendulum appliance K-loop combination. Eur J Orthod2010;32:459-65.
  2. Gianelly AA, Vaitas AS, Thomas WH, Berger DG. Distalizationof molars with repelling magnets. A case report. J Clin Orthod1998;22:40-4.
  3. Hilgers JJ. The pendulum appliance for class II non-compliancetherapy. J Clin Orthod 1992;26:706-14.
  4. Locatelli R, Bednar J, Dietz VS, Gianelly AA. Molar distalizationwith superelastic NiTi wire. J Clin Orthod 1992;26:277-9.
  5. Jones RD, White TM. Rapid class II molar correction with anopen-coil jig. J Clin Orthod 1992;26:661-4.
  6. Kalra V. The K-Loop molar distalizing appliance. J Clin Orthod1995;29:298-301.

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Riddhi and Laxmikanth Pendulum appliance and K-loop combination for molar distalization - A case report

  1. Jambi S, Thiruvenkatachari B, O'Brien KD, Walsh T.Orthodontic treatment for distalising upper first molarsin children and adolescents. Cochrane Database Syst Rev2013;23:CD008375.

 
  1. Shashidhar N, Rama S, Reddy M. Comparison of K-loop molardistalization with that of pendulum appliance-a prospectivecomparative study. J Clin Diagn Res 2016;10:20-3.

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