Evaluation of the Relationship Between Schneiderian Membrane Thickness and Sinus Floor Cortication Using Cone Beam Computed Tomography

Aim: In this study, we aimed to investigate the relationship between sinus floor cortication (SFC) and Schneiderian membrane thickness (SMT) through cone-beam computed tomography (CBCT) images. Materials and Methods: A total of 292 maxillary sinuses of 146 patients (61 males, 85 females) who underwent a CBCT scan for dental implant treatment were evaluated. SFC was classified as follows: type-1: sinus floor exhibiting similar or higher density than the surrounding cortical areas, type-2: sinus floor exhibiting lower density than the surrounding cortical areas, type-3: sinus floor exhibiting no cortical bone, and type-4: sinus floor exhibiting fusion of sinus floor bone and native crestal bone. We also investigated the relationship between the SFC types and SMTs measured from the highest border of the membrane to the sinus floor on cross-sectional images. Results: Type-1, type-2, type-3, and type-4 SFC were seen in 114, 102, 48, and 28 cases, respectively. The Schneiderian membrane was found to be thinner in type-1 SFC than in type-2 SFC. No significant difference was found between type-3 and type-4 SFC in terms of SMT. Discussion and Conclusion: Evaluation of SFC and SMT using CBCT can provide information about implant stability and survival in treatment after sinus grafting. Although type-1 SFC is favorable for implant placement, it may also be associated with an increased risk of membrane perforation.