| dc.description.abstract | Rehabilitation of posterior edentulous region of maxilla requires some considerations such as pneumatization of maxillary sinus, residual ridge resorption and low residual ridge height. In this area sinus lift procedure is carried out to increase bone height by elevating the Schneiderian membrane. The most prominent problem in this surgery is perforation of the Schneiderian membrane. This membraneEs thickness is of great importance in preventing perforation or rupture of the membrane. The aim of this study was to investigate the association of lower maxillary sinus dimensions with the Schneiderian membrane thickness using CBCT images. . Method and materials: In this retrospective study, 130 CBCT images of patientsE upper jaw, in the Clinic of Oral and Maxillofacial Radiology in 2012, were studied. Coronal-slice images were prepared at the mesiobuccal root of maxillary first molar. Then membrane thickness, the angle of convergence of lateral and medial wall of the sinus and mediolateral width of the sinus at 3- , 5- and 7-mm heights from the most inferior point of the sinus were measured. Data were analyzed with Pearson's statistical analysis using SPSS 13. The relationships of the angle of convergence and the width of the sinus at different heights with Schneiderian membrane thickness were investigated. Results: There were significant relationships between convergence angle (P<0.001, r = -0.561), and mediolateral sinus width at 3-mm height (P<0.001, r = -0.477), 5-mm height (P<0.001, r = -0.334) and 7-mm height (P<0.001, r = -0.347) with the Schneirderian membrane thickness. Conclusion: As the lower area of the maxillary sinus becomes narrower, the Schneirderian membrane thickness increases, reducing the risk of perforation or rupture of the membrane. | |
