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Change in sinus membrane dimension following sinus floor elevation: a retrospective cohort study.

OBJECTIVES
To investigate: (1) the effect of the lateral window technique for maxillary sinus augmentation on sinus membrane thickness, and (2) to identify factors associated with the mean postoperative surgical space.


MATERIAL AND METHODS
This retrospective cohort study included 37 sinuses corresponding to 37 consecutive patients referred for maxillary sinus augmentation procedures aiming to increase with deproteinized bovine bone the surgical space for dental implant placement in the posterior maxilla. A total of 74 preoperative and postoperative computed tomography were analyzed with regard to the thickness of the sinus membrane. A linear regression model was used to explain the difference between the mean preoperative and postoperative surgical space


RESULTS
No significant change in the membrane thickness was shown between pre and postoperative CT scans. The mean height of the graft was 12 mm (P < 0.001), resulting in a significant augmentation of the surgical space (P < 0.001). The multivariate analysis performed to identify variables associated with the postoperative surgical space shows that current smoking significantly reduces the chance to achieve the mean value of the surgical space normally expected in this type of surgical procedure (P = 0.02). No significant effect of complications, history of periodontal disease or ENT was found.


CONCLUSION
Our findings suggest that: (1) sinus floor augmentation via a lateral approach with deproteinized bovine bone alone has no impact on the natural sinus physiology; and (2) that the mean postoperative surgical space may be affected by smoking.