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VOLUME 23 , ISSUE 1 ( January, 2022 ) > List of Articles


Effect of Twin-block Appliance on Pharyngeal Airway, Sleep Patterns, and Lung Volume in Children with Class II Malocclusion

Akriti Batra, Vabitha Shetty

Keywords : Class II malocclusion, Lung volume, Pharyngeal airway, Sleep-disordered breathing, Twin block

Citation Information : Batra A, Shetty V. Effect of Twin-block Appliance on Pharyngeal Airway, Sleep Patterns, and Lung Volume in Children with Class II Malocclusion. J Contemp Dent Pract 2022; 23 (1):66-73.

DOI: 10.5005/jp-journals-10024-3289

License: CC BY-NC 4.0

Published Online: 21-05-2022

Copyright Statement:  Copyright © 2022; The Author(s).


Aim: In this study, we sought to evaluate the effect of the twin-block appliance on pharyngeal airway dimensions, sleep patterns, and lung volumes in growing children with class II malocclusion with a retrognathic mandible. Materials and methods: Twenty children aged 9–12 years with class II malocclusion with a retrognathic mandible participated in the study. A validated sleep questionnaire assessed the sleep patterns and the sleep problems of the children. The pre-treatment cephalometric variables and the pharyngeal airway passage (PAP) dimensions were analyzed. Spirometry tests were performed to evaluate lung volumes. A custom-made twin-block appliance was fabricated, and children were instructed to wear it for a minimum of 10 months. All variables including sleep problems, cephalometric variables, and pharyngeal airway measurements were evaluated post-treatment. Spirometry tests were re-evaluated at the end of the twin-block treatment. All data were statistically analyzed. Results: Post-twin-block appliance treatment, there was a definite decrease in snoring, noisy breathing, and sleeping with mouth open. The sella-nasion to B point angle (SNB), mandibular length, the depths of oropharynx, nasopharynx, and hypopharynx as well as the height of nasopharynx (HNP) were significantly increased post-treatment (p <0.001). The length and thickness of soft palate (SPI) increased significantly (p <0.001), while its inclination decreased significantly (p <0.001). We found improvements in forced vital capacity (FVC) and forced expiratory volume at 1 second (FEV1); however, the changes were statistically not significant (p = 0.88 and p = 0.78). Conclusion: Twin-block appliance significantly increased the pharyngeal airway dimensions and improved the length and thickness of the soft palate in children with class II malocclusion. Post-twin-block treatment showed a considerable reduction in the sleep problems of the children. The lung volume measurements showed improvement; however, it was not statistically significant. Clinical significance: Twin block may be used not only to correct the facial disharmony of children with a retrognathic mandible but also to improve the airway dimensions and lung volume as well as to reduce the sleep-disordered symptoms.

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