Raising the transcrestal sinus floor in the presence of antral pseudocysts, and in sinus floors with a normal Schneiderian membrane: a retrospective cohort study.

In this study we sought to investigate the influence of antral pseudocysts on the raising of the transcrestal sinus floor. We retrospectively studied two groups (test group: those with antral pseudocysts, and controls: those with normal Schneiderian membranes). The crestal approach with simultaneous placement of implants was used for all patients. Cone-beam computed tomography was done before, immediately afterwards, and 4-6 months postoperatively. Nineteen participants (16 male, three female, mean (SD) age 48 (10) years) were enrolled in the test group, and 73 (38 male, 35 female, 44 (11) years) in the control group. Immediately postoperatively the mean (SD) residual bone height was 5.15 (1.34) mm in the test group and 5.36 (1.28) mm in the control group (p = 0.15), and the raised heights of the sinus floor were 4.98 (2.01) mm and 5.47 (2.13) mm (p = 0.35) in the test and control groups, respectively. Four to six months postoperatively the endo-sinus bone gain values were 3.55 (2.46) mm and 4.03 (2.33) mm in the test and control groups, respectively (p = 0.26). All pseudocysts swelled immediately after operation. Four to six months postoperatively, two had remained unchanged, three had increased in volume, six had disappeared, and eight had decreased in volume. The survival rate of implants was 100% for both groups. Within the limitations of this study, transcrestal raising of the sinus floor in the presence of antral pseudocysts may be a viable technique, as they may not influence the clinical effects of raising the sinus floor during healing.