Radiological anatomical variations of the lateral nasal wall and anterior skull base amongst different populations: A systematic review and meta‐analysis

Objectives To determine the anatomical variations of the lateral nasal wall and anterior skull base amongst populations in different geographical regions. Design Systematic review and meta‐analysis. Methods Using PRISMA guidelines, SCOPUS and PUBMED databases were searched from inception until 1 March 2022. The regions and populations identified were from Europe, Asia, Middle East, Australia‐New Zealand‐Oceania, South America, North America and Africa. Random‐effects model was used to estimate the pooled prevalence with 95% confidence intervals (CIs). Heterogeneity was assessed using the I2 statistic and Cochran's Q test. Main outcome measures Anatomical variations of the lateral nasal wall and anterior skull base confirmed by computed tomography scan. Results Fifty‐six articles were included with a total of 11 805 persons. The most common anatomical variation of the ostiomeatal complex was pneumatization of the agger nasi (84.1%), olfactory fossa was Keros type 2 (53.8%) and ethmoids was asymmetry of the roof (42.8%). Sphenoethmoidal and suprabullar cells have a higher prevalence in North Americans (53.7%, 95% CI: 46.00–61.33) while asymmetry of ethmoid roof more common in Middle Easterns (85.5%, 95% CI: .00–100). Bent uncinate process has greater prevalence in Asians while supraorbital ethmoid cells and Keros type 3 more common in non‐Asians. The overall studies have substantial heterogeneity and publication bias. Conclusion Certain anatomic variants are more common in a specific population. The ‘approach of analysis’ plays a role in the prevalence estimates and consensus should be made in future studies regarding the most appropriate ‘approach of analysis’ either by persons or by sides.