Risk factors for velopharyngeal dysfunction following orthognathic surgery in the cleft population.

Abstract

This article highlights important trends in speech outcomes following orthognathic surgery in the cleft lip and palate populations. The geometric changes in the velopharyngeal port caused by maxillary advancement by standard means and distraction are only one consideration in predicting speech outcomes. Myriad and variable preoperative risk factors, both anatomic and functional, have been identified in the literature because of weaknesses in experimental design and small patient populations. Therefore, elucidating risk factors for postoperative velopharyngeal dysfunction remains a challenge in our field. Recent pharyngeal morphologic studies using computed tomography demonstrate volumetric discrepancies in the unilateral and bilateral cleft lip and palate populations before and after orthognathic surgery, suggesting differing requirements of velar adaptation among these two populations. Perceptual and instrumental speech evaluation studies and cephalometric correlates revisit 'borderline' velopharyngeal insufficiency and isolate preoperative velar length as a risk factor for velopharyngeal dysfunction following orthognathic surgery. Research design heterogeneity, small patient populations, and inherent risk of bias of retrospective reviews obscure velopharyngeal dysfunction risk factor identification prior to orthognathic surgery. However, recent reports on the volumetric changes in the pharyngeal airway and preoperative 'borderline' velopharyngeal insufficiency and velar length offer improved predictive value in anticipating postoperative velopharyngeal dysfunction.