Maxillary sinus pneumatization in healthy dentate individuals: an overview of systematic reviews

Background Maxillary sinus pneumatization is a dynamic physiological process that alters the anatomical relationship between the sinus floor and posterior maxillary dentition. Excessive pneumatization can reduce alveolar bone height, complicating implant placement and increasing the need for sinus augmentation. Although widely investigated in edentulous and pathological conditions, evidence in healthy, dentate individuals remains limited. Objective To synthesise evidence from systematic reviews on the development, pneumatization, and volumetric variation of the maxillary sinus in healthy dentate individuals, and to assess the influence of age, gender, ethnicity, and geography. Methods PubMed, Scopus, and Cochrane databases were searched up to 14 October 2025 using MeSH terms (“maxillary sinus pneumat*,” “maxillary sinus enlarge*,” “maxillary sinus develop*”). Systematic reviews and meta-analyses in dentate populations were included, while studies on pathology, edentulism, or surgical interventions were excluded. Methodological quality was assessed using AMSTAR-2, Glenny, JBI, CASP, and ROBIS tools. Reporting followed PRIOR and PRISMA2020 guidance for overviews. Corrected Covered Area (CCA) analysis was used to assess overlap between reviews. Results Six systematic reviews were included from 352 records. Overall methodological quality was high (mean compliance 90–93%). Adult sinus volumes ranged from 12–20 cm 3 , with consistent variation by age, gender, and ethnicity. Post-pubertal males exhibited 10–20% larger sinus volumes than females. Across 173 study occurrences (153 unique primary studies), the CCA was 2.6%, indicating minimal overlap. Conclusions Maxillary sinus morphology demonstrates substantial inter-individual variability driven by developmental and demographic factors. Despite high methodological quality, the current evidence base is largely descriptive and cross-sectional. No review identified definitive causal mechanisms or longitudinal evidence explaining sinus pneumatization, highlighting a critical gap for future research.