Radiological evaluation of sinus lift operation: what the general radiologist needs to know

Anatomical variation of the maxillary sinus in cone beam computed tomography

Purpose. The aim of this paper is to report a case in which the cone beam computed tomography (CBCT) was important for the confirmation of the presence of maxillary sinus septum and, therefore, the absence of a suspected pathologic process. Case Description. A 27-year-old male patient was referred for the assessment of a panoramic radiograph displaying a radiolucent area with radiopaque border located in the apical region of the left upper premolars. The provisional diagnosis was either anatomical variation of the maxillary sinuses or a bony lesion. Conclusion. The CBCT was important for an accurate assessment and further confirmation of the presence of maxillary septum, avoiding unnecessary surgical explorations.

Septa within the sinus: effect on elevation of the sinus floor

Elevation of the sinus floor allows the correct number and length of oral implants to be placed. The sinus membrane is dissected blindly, usually by a crestal approach, but several internal configurations of the maxillary sinus or intrasinus septa can cause problems. We studied 150 sinuses from 40 male cadavers, and 35 randomised male patients by anatomical dissection and computed tomography. Forty-six subjects (61%) had no bony septa or had septa less than 4mm. Twenty-nine (39%) had bony septa of which seven were incomplete, one had a complete bony septum in each maxillary sinus, and 20 had symmetrical bony septa. We present the results of a study of bony intramaxillary sinus septa and the potential problems they can cause during elevation of the sinus floor.