Prevalence, Morphology and Location of Maxillary Sinus Septa using Cone Beam Computed Tomography (CBCT): A Review with Emphasis on North Indian Populations

AbstractBackground: Maxillary sinus septa (Underwood's septa) are common anatomical variations that may complicate sinus augmentation and posterior maxillary implant placement. Conebeam computed tomography (CBCT) allows precise three dimensional evaluation of septa morphology, number, orientation, height, and location.Objective: This review aimed to summarize CBCT based literature on the prevalence, morphology, and typical locations of maxillary sinus septa, with emphasis on North Indian populations, and to discuss the clinical implications and limitations of CBCT for surgical planning.Methods: A systematic search of PubMed/PMC, Scopus, and Google Scholar was conducted for studies up to 2025 using keywords related to maxillary sinus septa and CBCT. Human CBCT or CT studies with ≥5 patients and quantitative data on septa prevalence or morphology were included. Extracted data included prevalence, septa number, orientation, height, location, dentition correlation, and CBCT parameters.Results: The global pooled prevalence of maxillary sinus septa is approximately 41% per patient, though individual studies report 25–56% depending on population andmethodology. North Indian CBCT studies report lower prevalence (8.9–21.3%) but similar morphology predominantly single, bucco-palatal orientation, middle region (first molar area) predominance, and mean height 4–8 mm. Presence of septa increases the risk of Schneiderian membrane perforation during lateral window sinus augmentation. CBCT limitations include voxel size, field of view (FOV), and inter-observer variability.Conclusions: CBCT is the imaging modality of choice for preoperative evaluation of maxillary sinus septa. Standardized reporting and awareness of CBCT limitations improve surgical safety and inter-study comparability. Population specific data, particularly from North India, highlight variability that should guide clinical planning.