Kim HJ, Yea S, Kim KH, et al. - In this retrospective study, researchers compared the survival rates of implants placed following 1-stage or 2-stage maxillary sinus floor augmentation by the lateral window technique (SFALW) performed on the residual bone of less than 4 mm. This research was carried out on the basis of dental records and radiographs acquired from patients receiving SFALW between March 2006 and June 2014, followed up between March 2006 and December 2017. According to the SFALW performed, they were divided into 1-stage and 2-stage groups. To examine the influence of multiple variables on implant failure, multivariable logistic regression analysis was used. A total of 395 implants in 167 patients fulfilled the criteria for inclusion. According to the 10-year cumulative survival rates, no statistically significant difference was found between implants following 1-stage and 2-stage maxillary SFALW performed on the residual bone height of less than 4 mm. Multivariable logistic regression analysis showed that implant failure after prosthetic loading was considerably affected by implant length and functional time.