Significant correlations among AHI, neck circumference, cephalometric parameters, and upper airway size in patients with OSAS
| Parameters | NC (cm) | PNS-U (mm) | SP-max (mm) | MP-H (mm) | EU | NH | IH |
|---|---|---|---|---|---|---|---|
| AHI | .411 | .363 | .339 | .420 | −.446 | .376 | |
| NC | 1000 | .383 | |||||
| PNS-U | .383 | 1000 | .422 | .545 | |||
| SP-max | .422 | 1000 | −.365 | ||||
| MP-H | .545 | 1000 | .306 | ||||
| SNB (angle) | .380 | ||||||
| IU | .325 |
Note.—Values are correlation coefficients. Significance is defined as P < .05. AHI indicates apnea-hypopnea index; OSAS, obstructive sleep apnea syndrome; NC, neck circumference; PNS-U, distance from the posterior nasal spine to the tip of the uvula; SP-max, maximum distance of the soft palate perpendicular to PNS-U; MP-H, distance from mandibular plane to the hyoid bone; EU, cross-sectional area at level of uvula in expiration; NH, cross-sectional area at level of hypopharynx in tidal breathing; IH, cross-sectional area at level of hypopharynx in inspiration; SNB, angle where S is the midpoint of the sella, N is the nasion, and B is the deepest point on the outer mandibular contour; IU, cross-sectional area at level of uvula in inspiration.