Clarifying the mechanism of effect of the Bionator for treatment of maxillary protrusion: A percentile growth study

Authors

  • H Oda Division of Orthodontics, Department of Comprehensive Dentistry, Yokohama Clinical Education Center, Kanagawa Dental University, Yokohama
  • M Sandou Private Practice, Kiryu
  • C-M Lin School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei
  • M Kamata Private Practice, Fujisawa
  • T Kawata Orthodontic Science, Division of Oral Science, Graduate School, Kanagawa

DOI:

https://doi.org/10.23804/ejpd.2016.3.7.213

Keywords:

Bionator, Bionator with expansion screw, Class II, Craniofacial growth, Percentiles

Abstract

AIM: The reported effects of Bionator treatment in patients with mandibular retrognathism are conflicting. This study evaluated the changes in craniofacial morphology resulting from treatment with a Bionator, based on measurement percentiles previously reported, to clarify the mechanism of the effect of this commonly used functional device. METHODS: Study Design: Retrospective. Setting: A private orthodontic clinic. Participants: Forty-two children (mean age, 10.13 years) requiring treatment with a Bionator for Class II malocclusion (mandibular retrognathism). Children were randomly assigned to a Bionator group with or without an expansion screw. Measurements on lateral cephalometric radiographs were taken before and upon completion of Bionator treatment. All parameters measured were characterised according to the measurement percentiles previously reported. Each parameter was compared before and after treatment for all patients and for each treatment group using Wilcoxon's test.