PurposeInsufficient knowledge of the anatomy of the maxillary sinuses prior to sinus graft surgery may lead to perioperative or postoperative complications. This study sought to characterize the position of the posterior superior alveolar artery (PSAA) within the maxillary sinuses using cone-beam computed tomography (CBCT).Materials and MethodsA total of 300 patients with edentulous posterior maxillae, including 138 females and 162 males with an age range of 33-86 years, who presented to a radiology clinic between 2013 and 2015 were enrolled in this retrospective cross-sectional study. The distance from the inferior border of the PSAA to the alveolar crest according to the residual ridge classification by Lekholm and Zarb, the distance from the PSAA to the nasal septum and zygomatic arch, and the diameter and position of the PSAA were all assessed on patients' CBCT scans. The data were analyzed using the Mann-Whitney test and the t-test.ResultsThe PSAA was detected on the CBCT scans of 87% of the patients; it was located beneath the sinus membrane in 47% of cases and was intraosseous in 47% of cases. The diameter of the artery was between 1 and 2 mm in most patients (72%). The mean diameter of the artery was 1.29±0.39 mm, and the mean distances from the PSAA to the zygomatic arch, nasal septum, and alveolar crest were 22.59±4.89 mm, 26.51±3.52 mm, and 16.7±3.96 mm, respectively.ConclusionThe likelihood of detecting the PSAA on CBCT scans is high; its location is intraosseous or beneath the sinus membrane in most patients. Determining the exact location of the PSAA on CBCT scans preoperatively can help prevent it from being damaged during surgery.

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In this study, hydroxyapatite nanoparticles containing 10% doxycycline, a structural isomer of tetracycline, was prepared by the co-precipitation method. It was added to collagen solution for the preparation of the scaffold with freeze-casting method in order to develop a composite scaffold with both antibacterial and osteoinductive properties for repairing bone defects. The scaffolds were evaluated regarding their morphology, porosity, degradation and cellular response. The scaffolds for further investigation were added in a rat calvaria defect model. The study showed that after eight weeks, the bone formation was relatively higher in the collagen/nano-hydroxyapatite/doxycycline group with completely filled defect when compared with other groups. Histopathological evaluation showed that the defect in the collagen/nanohydroxyapatite/doxycycline group was fully replaced by the new bone and connective tissue. Our results provide evidence supporting the possible applicability of doxycycline-containing scaffolds for successful bone regeneration.

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