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The biological adaptation of the human lineage to its environment is a recurring question in paleoanthropology. Particularly, how eco‐geographic factors (e.g., environmental temperature and humidity) have shaped upper airway morphology in hominins have been subject to continuing debate. Nasal shape is the result of many intertwined factors that include, but are not limited to, genetic drift, sexual selection, or adaptation to climate. A quantification of nasal airway (NA) morphological variation in modern human populations is crucial to better understand these multiple factors. In the present research, we study 195 in vivo CT scans of adult individuals collected in five different geographic areas (Chile, France, Cambodia, Russia, and South Africa). After segmentation of the nasal airway, we reconstruct 3D meshes that are analyzed with a landmark‐free geometric morphometrics method based on surface deformation. Our results highlight subtle but statistically significant morphological differences between our five samples. The two morphologically closest groups are France and Russia, whose NAs are longer and narrower, with an important protrusion of the supero‐anterior part. The Cambodian sample is the most morphologically distinct and clustered sample, with a mean NA that is wider and shorter. On the contrary, the Chilean sample form the most scattered cluster with the greatest intra‐population variation. The South African sample is morphologically close to the Cambodian sample, but also partially overlaps the French and Russian variation. Interestingly, we record no correlation between NA volume and geographic groups, which raises the question of climate‐related metabolic demands for oxygen consumption. The other factors of variation (sex and age) have no influence on the NA shape in our samples. However, NA volume varies significantly according both to sex and age: it is higher in males than in females and tends to increase with age. In contrast, we observe no effect of temperature or humidity on NA volume. Finally, we highlight the important influence of asymmetries related to nasal septum deviations in NA shape variation. [ABSTRACT FROM AUTHOR]

Background: Double-jaw surgeries are known to be painful and to require opioids. Maxillary (V2) and mandibular (V3) nerves block could provide adequate pain management with minimal opioid-related side effects. Our main objective was to evaluate the analgesic effect of bilateral ultrasound-guided V2 and V3 combined nerves block in patients undergoing double-jaw orthognathic surgery., Methods: In this single-blind, randomized control study, 50 patients were prospectively allocated to either bilateral ultrasound-guided V2 and V3 combined nerves block or intraoral infiltration of local anesthetic. Primary outcome was the cumulative oral morphine equivalent (OME) consumption assessed at postoperative day 1. Secondary outcomes were cumulative OME consumption and pain scores in recovery room and at postoperative day 2, intraoperative anesthetic consumption, and opioid-related side effects. Preoperative anxiety was investigated by the Amsterdam Preoperative Anxiety and Information Scale (APAIS)., Results: Compared with infiltration, ultrasound-guided regional anesthesia reduced cumulative OME consumption on day 1 (45.7±37.6 mg vs 25.5±19.8 mg, respectively, mean difference of -20.1 (95% CI -37.4 to -2.9) mg, p=0.023) and day 2 (64.5±60 mg vs 35.8±30.2 mg, respectively, mean difference of -28.7 (95% CI -55.9 to -1.43) mg, p=0.040). Interestingly, worst pain score and cumulative OME consumptions on day 2 were positively correlated with the APAIS (Pearson's correlation coefficient of 0.42 (p=0.003) and 0.39 (p=0.006), respectively)., Conclusion: Bilateral ultrasound-guided V2 and V3 combined nerves block reduces postoperative opioid consumption by about 50% in patients undergoing double-jaw surgery., Trial Registration Number: NCT05351151., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2024. Re-use permitted under CC BY. Published by BMJ.)