Oral Biol Res.  2023 Jun;47(2):35-42. 10.21851/obr.47.02.202306.35.

Immediate effect of mandibular advancement and vertical mouth opening on the pharyngeal airway space in growing patients

• Kim SH

• KMID: 2544207
• DOI: http://doi.org/10.21851/obr.47.02.202306.35

Abstract

This study aimed to assess the alterations in the pharyngeal airway space (PAS) due to mandibular advancement (MA) and mouth opening using lateral cephalograms and establish their relationship with surrounding structures that cause these changes. Twentyseven patients with a chief complaint of mandibular retrognathism (15 males and 12 females) were included. Two lateral cephalograms of each patient were obtained at different mandibular positions: centric occlusal and anterior edge-to-edge bite positions. To compare changes in the surrounding structures and PAS, paired t-test was employed. Correlation tests between the changes in the mandible and PAS were performed using Pearson correlation analysis. A statistically significant increase in the PAS was observed due to MA and mouth opening. The length of the tongue increased (p<0.001), whereas its height decreased (p<0.001). Furthermore, the soft palate advanced frontally (p<0.001), and the hyoid bone was displaced superiorly (p=0.001). A positive correlation was found between the changes in the mandible and PAS of the velopharyngeal area. In patients with growing mandibular retrognathism, MA and mouth opening increased the dimensions of the PAS due to improvements in the tongue, soft palate, and superior positioning of the hyoid bone.

Keyword

Airway control; Mandible; Retrognathism