Three-dimensional comparative changes in the pharyngeal airway of patients with cleft after two-jaw orthognathic surgery

Abstract

Background: The present study evaluated the three-dimensional changes of the pharyngeal airway after orthognathic surgery (OGS) in patients with unilateral and bilateral clefts, and in unilateral cleft patients with and without pharyngeal flap (PF). Methods: Forty-five patients with unilateral or bilateral clefts undergoing OGS were enrolled. Cone-beam computed tomographic images were obtained before and after OGS. We measured the pharyngeal airway volumes, minimal cross-sectional area, and the horizontal displacement of facial landmarks. Results: The patients with bilateral cleft exhibited smaller initial velopharyngeal volume (unilateral, 8623 mm3; bilateral, 7781 mm3; P = 0.211), whereas the velopharyngeal volume increased significantly with a median of 744 mm3 after OGS (P = 0.031). The median horizontal displacement of A point was 2.9 and 2.6 mm among the patients with unilateral and bilateral clefts, respectively (P = 0.276), and the median horizontal displacement of B point was −2.9 and −3.3 mm among patients with unilateral and bilateral clefts, respectively (P = 0.618). The unilateral cleft patients with PF exhibited lower initial velopharyngeal volume (patients with a history of PF surgery, 7582 mm3; patients without a history of PF surgery, 8756 mm3; P = 0.129) and a lower increase in velopharyngeal volume (patients with a history of PF surgery, 437 mm3; patients without a history of PF surgery, 627 mm3; P = 0.739) after OGS. Conclusions: Midface hypoplasia and the decrease in the velopharyngeal volume were more prominent among the bilateral cleft patients and the unilateral cleft patients with PF. After OGS, the velopharyngeal volume increased considerably among the bilateral cleft patients, but no considerable differences were noted among the unilateral cleft patients with PF. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.