Evaluating Maxillary Sinus Septa Using Cone Beam Computed Tomography: Is There a Difference in Frequency and Type Between the Dentate and Edentulous Posterior Maxilla?

PURPOSE: To analyze and compare the frequency, type, and location of maxillary sinus septa in patients with a dentate and an edentulous posterior maxilla using cone beam computed tomography (CBCT) imaging.

MATERIALS AND METHODS: The study consisted of 100 maxillary sinuses: 50 from patients with a dentate and 50 from patients with an edentulous posterior maxilla. The aim was to assess the frequency, morphology, and location of maxillary sinus septa in axial, sagittal, and coronal CBCT images. Images were only included in this study provided that patients were older than 30 years of age, at least one maxillary sinus was completely visible in the field of view (FOV), and the sinus membrane exhibited a mucosal thickening of a maximum 4 mm. Differences regarding age, sex, side, septa location, and type of dentition (dentate/edentulous posterior maxilla) were analyzed.

RESULTS: The mean age of the 100 patients (66 women, 34 men) was 58.3 years. A total of 60 sinus septa were found in exactly half of the evaluated sinuses. The major part of the septa was found on the floor of the maxillary sinus (n = 34/56.7%). Of these, the majority was located in the posterior maxilla in the region of the second molars (n = 27/79.4%). The most common orientation of the septa was coronal (63.3%), followed by septa in relation to the infraorbital canal (23.3%). Regarding the status of the dentition in the posterior maxilla in relation to the distribution of sinus septa, septa were present in 26 (52%) dentate and in 24 (48%) edentulous regions. Thus, for a potential influence of the status of the dentition in the posterior maxilla on the frequency of sinus septa, no significant impact was found (P = .69).

CONCLUSION: Sinus septa are frequent anatomical structures, and are found equally often in patients with a dentate and an edentulous posterior maxilla. This is of clinical relevance, as patients with missing teeth in the posterior area of the maxilla are often in need of a sinus floor elevation (SFE) procedure when dental implant placement is intended. As sinus septa are reported to be an important reason for surgical complications during SFE, a three-dimensional radiographic examination using CBCT prior to surgery might be helpful for diagnostic evaluation and treatment planning.