Background: Body position and anesthesia may alter nasal anthropometric measurements, potentially affecting both preoperative assessment and intraoperative decisions in rhinoplasty. Quantifying these effects is essential for the accurate evaluation of nasal morphology. Methods: Thirty-five patients (28 females, 7 males; mean age 27.9 ± 6.95 years) undergoing primary rhinoplasty were prospectively included. Standardized lateral photographs were obtained in three conditions: upright, preanesthetic supine, and postanesthetic supine. Linear distances were measured using a digital caliper in a position replicating the photographic setup, and angular parameters were calculated from the photographs using ImageJ software (version 1.53, National Institutes of Health, Bethesda, MD, USA). Statistical analyses were performed to compare nasal measurements among the three positions. Results: The nasion–pronasale distance increased in the preanesthetic supine compared with the upright position (p < 0.001), while the pronasale–alar curvature distance remained unchanged (p = 0.984). The nasofrontal angle was higher upright (p < 0.001), whereas the nasolabial (p < 0.001) and nasomental (p = 0.010) angles were greater in the preanesthetic supine position. After anesthesia, both nasion–pronasale (p < 0.001) and pronasale–alar curvature (p = 0.001) distances increased further, while the nasofrontal angle remained higher upright (p < 0.001). Conclusions: Supine positioning and anesthesia significantly modify nasal profile parameters. Awareness of these predictable morphologic changes can help surgeons avoid misinterpretation and improve the accuracy of preoperative planning, intraoperative evaluation, and postoperative assessment.

Background: Obstructive sleep apnea syndrome (OSA) is a significant disorder characterized by recurrent upper airway obstruction. Cervical vertebral alignment and lordosis angles may influence airway cross-sectional area. This study aimed to investigate the relationship between cervical lordosis angles and disease severity in patients with OSA. Methods: The study included 30 patients with OSA (mild n = 6, moderate n = 11, severe n = 13 based on Apnea–Hypopnea Index [AHI]) and 30 non-OSA controls presenting with mechanical neck pain. C1–C2, C1–C7, and C2–C7 angles were measured using the Cobb method on lateral cervical cephalometric radiographs. Additional soft tissue and airway parameters — prevertebral soft-tissue thickness at C2 (PST-C2) and C4 (PST-C4), posterior airway space (PAS), and mandibular plane–hyoid distance (MP-H)— were measured as anatomical surrogates given the unavailability of BMI data. Multiple linear regression (ANCOVA) models adjusting for age and sex were constructed for each cervical angle. Results: All cervical angles were significantly reduced in patients with OSA compared to controls (C1–C2: 25.51 ± 6.47° vs 33.3 ± 4.44°; C1–C7: 35.0 ± 11.9° vs 51.2 ± 7.34°; C2–C7: 9.19 ± 10.6° vs 19.9 ± 5.05°; all p < 0.001). Within the OSA group, a significant moderate negative correlation was found between AHI and the C2–C7 angle (ρ = − 0.522, p = 0.003), while the C1–C7 angle showed a borderline association (ρ = −0.361, p = 0.050) and C1–C2 did not reach significance (ρ = +0.118, p = 0.534). After adjustment for age and sex, group membership (OSA vs. control) remained a strong, independent predictor of all three cervical angles (all p < 0.001), whereas neither age nor sex was a significant predictor (all p > 0.34). PST-C2 was significantly higher in the OSA group (4.93 ± 1.06 mm vs. 4.30 ± 0.70 mm, p = 0.017), whereas PST-C4, PAS, and MP-H did not differ significantly between groups (all p > 0.05), and none of these parameters correlated significantly with the C2–C7 angle. Conclusions: Significant cervical lordosis loss was observed in patients with OSA compared to non-OSA controls, with the C2–C7 angle showing a significant negative correlation with AHI within the OSA group; this association remained robust after adjustment for age and sex. Supplementary soft tissue and airway measurements showed no significant correlation with cervical alignment or AHI, suggesting the observed association is not simply attributable to regional soft-tissue thickness or airway narrowing; however, without direct BMI data, a confounding role of systemic adiposity cannot be excluded. These findings suggest a potential association between cervical posture and upper airway dynamics; however, larger prospective studies are required to confirm clinical utility.