A new method to evaluate volumetric changes in sinus augmentation procedure

Background In sinus augmentation procedure, the assessment of volume changes of grafted materials is important both in the clinical practice and in dental research to evaluate the features of filling materials. Purpose In this study, we assessed the repeatability of a new method proposed to evaluate volumetric changes following sinus lift augmentation procedure. Materials and Methods In 10 patients, maxillary sinus augmentation procedure with simultaneous implant placement was performed. Maxillary cone beam computer tomographies were taken 1 week after surgery (T1) and 6 months after surgery (T2). At each evaluation the gap inside the implant between the fixture and the bottom of the screw was used as reference point (Rp), and a standardized volume of interest (VOI) centered on the Rp was selected. Masks were chosen to select the graft and bone tissue within the VOI; the volume at T1, T2, and the difference of volume between T1 and T2 were computed. Expert and non-expert operators performed the analysis. Method errors were computed. Results The error of the method was 1% for both intra-operator and inter-operator measurements. Tissue contraction at T2 was 19 ± 4% of the total initial volume. Conclusions The standardization of the method allows to obtain repeatable measurements.