Upper airway changes following single-step or stepwise advancement using the functional mandibular advancer

Upper airway changes following single-step or stepwise advancement using the Functional Mandibular Advancer

Fonksiyonel mandibular ilerletici kullanılarak yapılan tek seferde ve aşamalı ilerletmeye bağlı üst havayolu değişiklikleri

Isil Aras • Aylin Pasaoglu • Sultan Olmez • Idil Unal • Aynur Aras

Objectives Purpose of the present study was to determine and compare possible changes in the dimensions of the pharyngeal airway, morphology of the soft palate, and position of the tongue and hyoid bone after single-step or stepwise mandibular advancement using the Functional Mandibular Advancer (FMA). Patients and methods The sample included 51 peak-pubertal Class II subjects. In all, 34 patients were allocated to two groups using matched randomization: a single-step mandibular advancement group (SSG) and a stepwise mandibular advancement group (SWG). Both groups were treated with FMA followed by fixed appliance therapy; the remaining 17 subjects who underwent only fixed appliance therapy constituted the control group (CG). The study was conducted using pre- and posttreatment lateral cephalometricradiographs.Datawereanalyzedbypairedttest,one-way analysis of variance, and Pearson’s correlation coefficient. Result In the SWG and SSG, although increases in nasopharyngeal airway dimensions were not significant compared with those in the CG, enlargements in the
oropharyngeal airway dimensions at the level of the soft palate tip and behind the tongue, and decreases in soft palate angulation, were significant. Tongue height increased significantly only in the SWG. Compared with the CG, while forward movement of the hyoid was more prominent in SSG and SWG, the change in the vertical movement of the hyoid was not significant. No significant difference between SWG and SSG was observed in pharyngeal airway, soft palate, tongue or hyoid measurements. Conclusions The mode of mandibular advancement in FMA treatment did not significantly affect changes in the pharyngeal airway, soft palate, tongue, and hyoid bone.
Keywords Mandibular advancement  Functional orthodontic appliance  Pharynx  Cephalometry