Table 1.
Summary of studies on typical upper airway development.
Table 2.
Summary of boundaries of the pharyngeal regions.
Table 3.
Distribution of male and female cases per age group.
Fig 1.
Illustration of airway regions and measurements.
The airway was examined using landmark-derived planes orthogonal to the centerline, as described in text. The four airway regions bounded by five cross sectional areas, a-to-d as depicted in the right panel, were quantified developmentally using the following measurements: volume, region length, cross-sectional area (CSA), anterior-posterior distance, and lateral width—as defined in Table 5. The airway regions above the glottis (d; Table 5, definition 19), included the following pharyngeal regions: a. Nasopharynx (blue; definition 1); b. Oropharynx (red; definition 6); c. Laryngopharynx (cyan; definition 11); and the airway below the glottis consisted of the subglottal region (magenta; definition 22). The pharynx (Table 5, definition 16) consisted of all three supraglottal regions.
Fig 2.
3D airway model (choanae to trachea) of a 4-year 8-month old typically developing male as visualized in MATLAB.
Blue dots represent the 26 anatomic landmarks listed in Table 4. The centerline is shown in green, and CSAs closest to each of the anatomic landmarks are shown in red.
Table 4.
Description/definition of the 26 anatomic landmarks.
Table 5.
All upper airway variables examined.
Table 6.
Likelihood ratio test and Wald test results.
Fig 3.
Measurements extracted for pharyngeal region (3A. Nasopharynx; 3B. Oropharynx; 3C. Laryngopharynx; 3D. Pharynx; and 3E. Subglottal). Measurements extracted for each pharyngeal region (3A to 3E) is depicted in top panel image on left, with measurements as defined in Table 5 and consisting of: Top panel; the orthogonal volume, and the curvilinear/centerline volume-length. Bottom panel; the orthogonal cross-sectional area (CSA) (superior 3A, or inferior 3B–3E), its anterior-posterior distance (APDist), and lateral width (Width). Plots include measurements for male in blue filled square symbols, and for female in red shaded circle symbols. Pediatric data include linear fits for males (blue solid line) and females (red dashed line). Point estimate of modeled means and confidence intervals are plotted for adult data, and at ages 0 and 5 years respectively for males (purple) and female (magenta). The second Y-axis reflects the percent growth for males (blue, inwards tick orientation) and females (black, outwards tick orientation). Significance for sex differences at birth, age 5 years and/or adults are denoted with single, double, and triple asterisk(s) at the interval plots using the nominal α < 0.05, < 0.01, and < 0.001 levels respectively; the numeric p values are displayed in Table 6.
Table 7.
Age-specific mean (standard deviation) of the different measurement types for each pharyngeal region.