Volumetric measurement of manually drawn segmentations in cone beam computed tomography images of newly formed bone after sinus floor augmentation with bovine-derived bone substitutes.

Introduction: Precise volumetric measurement of newly formed bone after maxillary sinus floor augmentation (MSFA) can help clinicians in planning for dental implants. This study aimed to introduce a novel modular framework to facilitate volumetric calculations based on manually drawn segmentations of user-defined areas of interest on cone-beam computed tomography (CBCT) images MATERIAL & METHODS: Two interconnected networks for manual segmentation of a defined volume of interest and dental implant volume calculation, respectively, were used in parallel. The volume data of dental implant manufacturers were used for reference. The efficacy of this framework was demonstrated through practical applications for collecting CBCT data from patients after MSFA with the same quantity of two different bovine-derived bone substitutes: xenohybrid composite bone (Group I, n = 10) and hydroxyapatite (Group II, n = 10). The study was approved by the central Ethical Review Board of the federal state of Lower Austria (approval number: GS4-EK-4/451-2021). The volumes were measured immediately (T1) and 6 months (T2) after MSFA and before insertion of the dental implant. All measurements were analyzed for inter- and intravariability. P-values of >0.05 were obtained from the t-test analysis RESULTS: The manual delineation of Group II (n = 10) was easier than that of Group I (n = 10) due to the visual contrast of the CBCT scan. The mean volume was 861.65 ± 290.02 mm³ at T1 and 875.9 ± 288.96 mm³ at T2. This shows a moderate dispersion around the mean value, which indicates variability of the analyzed data DISCUSSION: The proposed network may be useful for the development of computer-based diagnostic systems for assessing the success of MSFA with bone replacement materials. The volumetric stability achieved with the two bone replacement materials were comparable.