International Journal of Clinical Pediatric Dentistry

Register      Login

VOLUME 14 , ISSUE S1 ( Special Issue (Pediatr Orthodont), 2021 ) > List of Articles


A Comparative Evaluation of the Dentoskeletal Treatment Effects Using Twin Block Appliance and Myobrace System on Class II Division I Malocclusion

Savitha Satyaprasad, Hurlihal Sharath Chandra, Ambili Raj, Nandan Suresh

Keywords : Class II malocclusion, Myobrace system, Myofunctional, Twin block

Citation Information :

DOI: 10.5005/jp-journals-10005-2013

License: CC BY-NC 4.0

Published Online: 27-12-2021

Copyright Statement:  Copyright © 2021; The Author(s).


The study aimed to evaluate the dentoskeletal effects of twin block appliance and myobrace system in treating skeletal Class II Division I malocclusions in growing children taking into account the effects of normal growth in an untreated control group. Twenty subjects with Class II Division I malocclusion considered as study group were allocated randomly to two treatment groups of 10 each, consecutively treated with twin block appliances (mean age 10.850 ± 1.37 years) and myobrace system (mean age 10.40 ± 1.89 years). Ten children (mean age 10.60 ± 1.77 years) with untreated Class II Division I malocclusion were considered as a control group to eliminate possible growth effects. At the start of the treatment and end of the observation period of 18–24 months, lateral cephalograms were taken. All the angular and linear parameters measured were subjected to statistical analysis. Twin block group subjects produced more measurable and statistically significant skeletal and dentoalveolar changes at the end of the observation period, demonstrated by correction of full cuspal Class II molar relationship to Class I molar relationship and yielding mandibular growth in increments greater in magnitude than the myobrace system. Meanwhile, the myobrace system-induced favorable dentoalveolar changes by a significant reduction of overjet. The retrognathic profile, however, improved in both the intervention groups as the upper lip protrusion, mentalis strain, and the lower lip curl were eliminated in striking contrast to the untreated control group. The study demonstrates that with appropriate patient selection both myobrace system and twin block appliances can be used in conjunction with the fixed appliance therapy to achieve more stable Class II corrections.

  1. Graber TM, Vanarsdall RL, Vig KW. Orthodontics: current principles and techniques. 5th ed., USA: Mosby; 2012. pp. 424–425.
  2. Tweed CH. Treatment planning and therapy in the mixed dentition. Am J Orthod 1963;49(12):900. DOI: 10.1016/0002-9416(63) 90219-7.
  3. Mcdonald RE, Avery DR, Dean JA. Dentistry for the child and adolescent. 8th ed., USA: Mosby; 2004. p. 673.
  4. McNamara JA. Components of class II malocclusion in children 8–10 years of age. Angle Orthod 1981;51(3):177–202. DOI: 10.1043/0003-3219(1981)0512.0.CO;2.
  5. Stahl F, Baccetti T, Franchi L, et al. Longitudinal growth change in untreated subjects with class II division 1 malocclusion. Am J Orthod Dentofac Orthop 2008;134(1):125–137. DOI: 10.1016/j.ajodo.2006.06.028.
  6. McNamara JA. Neuromuscular and skeletal adaptations to altered function in the orofacial region. Am J Orthod 1973;64(6):578–606. DOI: 10.1016/0002-9416(73)90290-x.
  7. Basciftci FA, Uysal T, Buyukerkmen A, et al. The effects of activator treatment on the craniofacial structure of class II division 1 patients. Eur J Orthod 2003;25(1):87–93. DOI: 10.1093/ejo/25.1.87.
  8. Trenouth MJ. Cephalometric evaluation of the twin-block appliance in the treatment of class II division 1 malocclusion with matched normative growth data. Am J Orthod Dentofac Orthop 2000;117(1):54–59. DOI: 10.1016/s0889-5406(00)70248-4.
  9. Tallgren A, Christiansen R, Ash MM, et al. Effects of a myofunctional appliance on orofacial muscle activity and structures. Angle Orthod 1998;3(3):249–258. DOI: 10.1043/0003-3219(1998)0682.3.CO;2.
  10. Mills CM, McCulloch KJ. Treatment effects of the twin block appliance: a cephalometric study. Am J Orthod Dentofac Orthop 1998;114(1):15–24. DOI: 10.1016/s0889-5406(98)70232-x.
  11. Usumez S, Uysal T, Sari Z, et al. The effects of preorthodontic trainer treatment on class II division I patients. Angle Orthod 2004;74(5):605–609. DOI: 10.1043/0003-3219(2004)0742.0.CO;2.
  12. OliveriaJr EB, Noeur PR, Almeida RC, et al. Cephalometric assessment of patients after treatment with trainer positioners –T4K. J Br OrthodOrthop Facial 2005;10:179–185.
  13. Lund DI, Sandler PJ. The effects of twin blocks: a prospective controlled study. Am J Orthod Dentofacial Orthop 1998;113(1):104–110. DOI: 10.1016/S0889-5406(98)70282-3.
  14. Das UM, Reddy D. Treatment effects produced by pre orthodontic trainer appliance in patients with class II division I malocclusions. J Indian Soc Pedod Prevent Dent 2010;28(1):30–33. DOI: 10.4103/0970-4388.60480.
  15. Sharma AK, Sachdev V, Singla A, et al. Skeletal and dentoalveolar changes concurrent to use of twin block appliance in class 2 division 1 cases with a deficient mandible: a cephalometricstudy. J Indian Soc Pedod Prev Dent 2012;30(3):218–226. DOI: 10.4103/0970-4388.105014.
  16. Clark WJ. The twin block technique. Am J Orthod 1998;93(1):1–18. DOI: 10.1016/0889-5406(88)90188-6.
  17. Sidlauskas A. The effects of the twin-block appliance treatment on the skeletal and dentolaveolar changes in class II division 1 malocclusion. Medicina (Kaunas) 2005;41(5):392–400.
  18. Illing HM, Morris DO, Lee RT. A prospective evaluation of bass, bionator and twin block appliances. Part 1—the hard tissues. Eur J Orthod 1998;20(5):501–516. DOI: 10.1093/ejo/20.5.501.
  19. Toth LR, McNamara JA. Treatment effects produced by the twin-block appliance and the FR-2 appliance of frankel compared.with an untreated Class II sample. Am J Orthod Dentofac Orthop 1999;116(6):597–609. DOI: 10.1016/s0889-5406(99)70193-9.
  20. Uysal T, Yagci A, Kara S, et al. Influence of pre-orthodontic trainer treatment on the perioral and masticatory muscles in patients with class II division 1 malocclusion. Eur J Orthod 2011(1):1–6. DOI: 10.1093/ejo/cjq169.
  21. Anastasi G, Putrino A. Cephalometric evaluation of mandibular changes following orthodontic treatment with preformed appliances on class II patients: a meta-analysis. Webmed Central Orthod 2014;5(1):WMC004491.
  22. Idris G, Hajeer MV, Al-Jundi A. Acceptance and discomfort in growing patients during treatment with two functional appliances: a randomized controlled trial. Eur J Pediatr Dent 2012;13(3):219–224.
  23. DeVincenzo JP. Changes in mandibular length before, during and after successful orthopedic correction of class II malocclusions using a functional appliance. Am J Orthod Dentofac Orthop 1991;99(3):241–257. DOI: 10.1016/0889-5406(91)70006-I.
  24. Pancherz H. A cephalometric analysis of skeletal and dental changes contributing to class II correction in activator treatment. Am J Orthod 1984;85(2):125–134. DOI: 10.1016/0002-9416(84)90004-6.
PDF Share
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.