The effects of mechanical vibration on Class II orthopaedic appliance therapy at different stages of skeletal maturity

Abstract

Mechanical vibration has been utilised in medicine to enhance bone integrity, muscle coordination, joint function and pain management. This has inspired its clinical application to dentofacial orthopaedics, which to date has not been explored. The purpose of this study was to evaluate and compare the effects of intraoral mechanical vibration stimulation during Class II functional appliance therapy at different maturity. 55 patients (11-18 years old) who attended the Sydney Dental Hospital for orthodontic treatment were randomised into 4 different groups. The 2 positive control groups with subjects who underwent Class II functional appliance therapy, with one group comprising subjects at peak pubertal stage and the other at late adolescent stage. The 2 treatment groups received Class II functional appliance therapy with concomitant intraoral mechanical vibration stimulated by a commercially available device, VPro5. One of the treatment groups consisted of subjects at peak pubertal stage and the other at late adolescent stage. Cone beam computed tomography (CBCT) records were taken before treatment and immediately after appliance removal. Cephalometric and 3D airway analysis were performed. All groups showed correction by maxillary incisor retraction, mandibular incisor proclination and varying degree of maxillary retrusion and mandibular protrusion. The results revealed an increase in dental compensation and a reduction in skeletal efficacy when mechanical vibration was used as an adjunct to Class II functional appliance during the late-adolescent stage. In contrast, there may be some benefit to vibration stimulation in provoking more substantial skeletal effects of during peak-pubertal stage. Additionally, intraoral mechanical vibration has been shown to enhance upper airway dimensions during Class II functional appliance therapy, as both experimental groups displayed greater airway volumetric changes during treatment, particularly in the oropharynx.