Objective The present study aimed to evaluate the clinical efficacy of hydraulic sinus floor elevation for the treatment of insufficient bone height in the posterior maxilla through a systematic review and Meta-analysis, so as to provide evidence for clinical practice. Methods Databases including PubMed, Embase, Cochrane Library, and Clinical Trials.gov were searched up to May 2025. Randomized controlled trials, non-randomized controlled trials, cohort studies, cross-sectional studies, and case-control studies that involved patients receiving hydraulic sinus floor elevation with simultaneous or delayed implant placement were included. Exclusion criteria comprised in vitro studies, animal experiments, narrative reviews, unpublished data, commentaries or expert opinions, studies with unclear sample sizes, and publications without full-text access or unavailable outcome data. Three investigators independently performed literature screening and quality assessment. A single-arm Meta-analysis was conducted using Stata 18.0 for studies meeting the inclusion criteria. The outcome measures were the incidence of sinus membrane perforation, implant survival rate, and endo-sinus bone gain. The Cochrane Risk of Bias 2 (RoB2) tool and the Joanna Briggs Institute (JBI) critical appraisal checklist were used to assess the methodological quality of randomized controlled trials and non-randomized controlled trials, respectively. The overall certainty of evidence was assessed using the GRADE（Grading of Recommendations Assessment, Development and Evaluation）system. Results Nineteen studies with 982 patients, 1 151 elevated sites, and 1 263 implants were finally included. The Meta-analysis showed that the intraoperative sinus membrane perforation rate of hydraulic sinus floor elevation was 2.0% [ES = 0.02, 95% CI (0.00, 0.04)] (18 studies, 1 061 sites); the implant survival rate was 99.0% [ES = 0.99, 95% CI (0.97, 1.00)] (17 studies, 1 253 implants); and the mean vertical bone gain was 7.80 mm. For this outcome, heterogeneity among studies was extremely high (I2 = 98.6%), thus only descriptive analysis was performed. Egger's test revealed no significant publication bias for the three outcomes. GRADE grading indicated very low certainty of evidence for mucosal perforation, implant survival rate, and endo sinus bone gain. Conclusion Current preliminary evidence suggests that hydraulic sinus lift may be a safe minimally invasive technique, but the evidence is very low, and more high quality, long term follow up randomized controlled clinical trials are still needed for further verification.

Objective To investigate the feasibility of ovariectomized cynomolgus monkey as an animal model of postmenopausal dry eye.Methods Six healthy adult female cynomolgus monkeys (aged 4-6 years old)were selected.Cynomolgus monkeys were divided into ovariectomized group and sham operation group by random number table.Bilateral ovariectomy was performed in each cynomolgus of the ovariectomy group,and the same operation was operated in the sham group but the ovaries were not removed.The venous blood of the lower extremities of each cynomolgus monkey was collected before operation and at 1 month,3 and 6 months after operation respectively.The concentrations of estradiol and testosterone were measured by radioimmunoassay.At the above time points,tear-liquid osmotic pressure detector 5600 was used to detect the tear osmotic pressure of cynomolgus monkeys in each group,and dry eye related examinations,including Schirmer Ⅰ test (S Ⅰ t),corneal fluorescein staining and conjunctive impression cytology were performed.Results Preoperative and postoperative serum estradiol,testosterone concentrations in the ovariectomy group were lower than those in the sham operation group,but there were no significant differences between the two groups (Fgroup =5.16,P =0.09;Fgroup =1.46,P =0.29).There was no significant difference in the osmotic pressure between the two groups (Fgroup =0.83,P=0.37).The osmotic pressure in the 3 months after ovariectomy was higher than that in the 1 month after ovariectomy in the ovariectomy group,with a significant difference between them (t =5.12,P ＜ 0.05).There was no significant difference in S Ⅰ t between ovariectomized group and sham operation group (Fgroup =0.06,P=0.82),the S Ⅰ t in the 3 months after ovariectomy was lower than that in the 1 month after ovariectomy in the ovariectomy group,with a significant difference between them (t =1.13,P＜0.05).There was no corneal fluorescein staining at each time points before and after ovariectomy in each group.The conjunctive impression cytology examination showed that,in the ovariectomy group,the morphology of conjunctival epithelial cells was normal,the number of conjunctival goblet cells was large,the periodic acid Schiff staining was purple before and 1 month after ovariectomy,which were similar to those in the sham operation group;three months after ovariectomy,the conjunctiva epithelial cell body was larger and had diverse forms,goblet cells were shrinked;six months after ovariectomy,the shapes of conjunctival epithelial cells were diverse and not easily been distinguished,the number of goblet cells was distinctly decreased.Conclusions The ocular conjunctival cells in the ovariectomized cynomolgus monkey have abnormal changes in morphology,and tear osmotic pressure increase,the ocular surface dynamic changes are consistent with the decrease of serum estrogen level,so ovariectomized cynomolgus monkeys can be used as sex hormone-related dry eye animal models.