Three-dimensional pharyngeal airway changes in dento-skeletal class II patients after two-jaw orthognathic surgery with segmentation - a pilot study

Abstract

Purpose: To investigate short- and long-term post-surgical three-dimensional changes of pharyngeal airway morphology and hyoid bone position in dento-skeletal class II deformity patients after two-jaw surgery with segmentation.

Methods: Relations between skeletal movement, hyoid bone position and three-dimensional pharyngeal airway changes were retrospectively analyzed on pre- and post-surgical CBCTs in dento-skeletal class II patients who underwent orthognathic two-jaw surgery with segmentation.

Results: While long-term significant reductions in length (P= 0.003), surface area (P= 0.042) and volume (P= 0.004) were found in the nasopharynx, the highly significant increases in oropharyngeal airway length, surface area, volume and the minimal cross-sectional area (P < 0.05) prevailed only in the short-term. Although a significant antero-superior movement of the hyoid bone was detected both in short- and long-term follow-up CBCTs (P < 0.05), only its superior, but not the anterior movement was found to be associated with an increased lateral width of the oropharyngeal minimal cross-sectional area.

Conclusion: Two-jaw orthognathic surgery with segmentations in dento-skeletal class II patients improved oropharyngeal airway parameters significantly in the short-, but not long-term.

Keywords: Dento-skeletal class II; Hyoid bone; Orthognathic surgery; Pharyngeal airway.