Velopharyngeal Space Assessment in Patients Undergoing Le Fort 1 Maxillary Advancement

Abstract

Background: The effects of maxillary advancement on velopharyngeal anatomy have primarily been studied using lateral cephalometric radiographs. However, with recent advances in orthognathic surgery, there is an increased need for more detailed and precise imaging such as computerized tomographic (CT) scan reconstructions, to help in surgical planning and to measure outcomes. The purpose of this study was to compare the pre- and post-operative velopharyngeal anatomic configuration modifications as measured on CT scans. Methods: This is a retrospective cohort study of 44 patients with and without cleft palate who were treated with maxillary advancement. The pre- and post-operative CT scans were compared with respect to pre-established landmarks. Linear distances, cross-sectional areas, and volumes were measured using 3-dimensional CT scan reconstructions. Results: For the linear distances measured, a statistically significant difference was found when comparing the pre- and post-operative measures of the narrowest part of the nasopharynx and the narrowest part of the retropalatal airway space ( P = 0.001 and 0.026, respectively). Retropalatal cross-sectional areas, nasopharyngeal cross-sectional areas, and the volumetric assessment of the nasopharyngeal space showed no statistically significant differences when comparing pre- and post-operative scans ( P < 0.05). Mean changes in the measures did not differ over time (pre- and post-operative) depending on whether there was a prior history of cleft palate repair. Conclusions: Although structural modifications of the pharyngeal space are inherent to maxillary advancement, its surface area and volume do not significantly change. The use of 3-dimensional reconstruction using CT scans should be the first choice for evaluation of the upper airway.

Changes in the pharyngeal airway after different orthognathic procedures for correction of class III dysplasia

“…Gokce et al [8] reported that 2-jaw surgery for correction of class III deformity leads to an increase in the airway volume. Saleh et al [33] found that despite the structural modifications following maxillary advancement, the surface area and volume of the airway did not change significantly.…”

Does Distraction Lower Risk of VPI Compared to Conventional Maxillary Advancement? A Retrospective Cohort Study of Adolescents with Cleft Palate

“…7 Re-creation of normal insertion of the levator veli palatini medially within the soft palate is the primary goal of initial soft palate repair. Because of both congenital and iatrogenic differences in VP anatomy not present in the non-CP ± L population and the anatomic relationship between the posterior maxilla and the levator veli palatini, sagittal advancement of the maxilla may interfere with the ability to achieve VP closure post-operatively in patients with CP ± L. [8][9][10] While there is generally consensus that the prevalence of VPI increases after maxillary advancement surgery in adolescents with CP ± L, the magnitude of and subgroups more susceptible to this change are highly variable due to significant heterogeneity in the methodologic approach to these questions in the literature. Following CO, the proportion of patients with a decline in VP function has ranged from 11% to 24% across studies.…”

“…7 Re-creation of normal insertion of the levator veli palatini medially within the soft palate is the primary goal of initial soft palate repair. Because of both congenital and iatrogenic differences in VP anatomy not present in the non-CP ± L population and the anatomic relationship between the posterior maxilla and the levator veli palatini, sagittal advancement of the maxilla may interfere with the ability to achieve VP closure post-operatively in patients with CP ± L. 8–10…”