AIM:To analyze the influencing factors of visual outcome after vitrectomy for polypoidal choroidal vasculopathy(PCV)combined with vitreous hemorrhage and establish a predictive model.METHODS: A retrospective analysis was conducted on the clinical data of 129 cases(129 eyes)of patients who underwent vitrectomy for PCV combined with vitreous hemorrhage from June 2021 to January 2024 in our hospital. They were divided into elevated group(71 eyes)and non-elevated group(58 eyes)according to visual outcome at early posoperative stage(within 24 mo). Another 30 cases(30 eyes)of PCV with vitreous hemorrhage undergoing vitrectomy were selected as external validation data. The predictive value of the model for the postoperative visual outcomes of both internal and external populations was evaluated.RESULTS: The non-elevated group had a higher proportion of patients aged ≥60 years, diabetes, continuous abnormalities of the ellipsoid zone(EZ)during surgery, bleeding involving the macular fovea, and postoperative retinal scar formation than the elevated group were independent factors affecting postoperative visual acuity(all P<0.05). The AUC of the predictive model for predicting the postoperative visual outcomes of internal and external populations was 0.824(95%CI: 0.750-0.898)and 0.809(95%CI: 0.723-0.865), respectively.CONCLUSION:Patients aged ≥60 years, diabetes, intraoperative continuous abnormalities of EZ, bleeding involving the macular fovea, and postoperative retinal scar formation are influencing factors for visual outcome after vitrectomy in patients with PCV combined with vitreous hemorrhage. A predictive model based on those factors has been established, which has a certain predictive value for postoperative visual outcome.

The problems caused by proximal contact loss(PCL)of dental implants have been a mainstream research topic in recent years,and scholars are unanimously committed to analyzing their causes and related factors,aiming to identify solutions to the problems related to PCL.The effects of the anterior component of force(ACF),the lifelong re-molding of the adult craniofacial jaw and alveolar socket,and the osseointegration characteristics of dental implants are the main causes of PCL.On the one hand,the closing movement of the mandible causes the ACF of the tooth to move through the posterior molar cusp.Moreover,drifting between the upper and lower posterior teeth and mandibular anteri-or teeth can cause the anterior teeth of the upper and lower jaws to be displaced labially.On the other hand,reconstruc-tion of the jaw,alveolar socket and tooth root,the forward horizontal force of the masticatory muscles,the dynamic com-ponent of the jaw and the forward force generated by the oblique plane of the tooth cusp can cause the natural tooth to experience near-middle drift.Additionally,natural teeth can shift horizontally and vertically and rotate to accommodate remodeling of the stomatognathic system and maintain oral function.Nevertheless,the lack of a natural periodontal mem-brane during implant osseointegration,the lack of a physiological basis for near-medium drift,the small average degree of vertical motion and the integrated silence of dental implants without the overall drift characteristics of natural teeth increases the probability of PCL.The high incidence of PCL is clearly associated with the duration of prosthesis delivery and the mesial position;but it is also affected by the magnitude of the bite force,occlusion,the adjacent teeth,restora-tion design,implant location,jaw,and patient age and sex.PCL has shown a significant correlation with food impaction,but not a one-to-one correspondence,and did not meet the necessary and sufficient conditions.PCL is also associated with peri-implant lesions as well as dental caries.PCL prevention included informed consent,regular examinations,se-lection of retention options,point of contact enhancement,occlusal splints,and the application of multipurpose digital crowns.Management of the PCL includes adjacent contact point additions,orthodontic traction,and occlusal adjust-ment.Existing methods can solve the problem of food impaction in the short term with comprehensive intervention to seek stable,long-term effects.Symmetric and balanced considerations will expand the treatment of issues caused by PCL.

Objective:To evaluate the incidence of birth defects in offspring using frozen semen from sperm banks by meta-analysis, to provide scientific evidence for the safety and reliability of frozen semen in assisted reproductive technology (ART).Methods:China National Knowledge Infrastructure (CNKI), Wanfang Digital Database (Wanfang), VIP Citation Database (VIP), CBMDisc and PubMed were searched about birth defects using frozen semen in ART since the establishment to October 1, 2019. Literatures were screened according to the predefined inclusion and exclusion criteria and evaluated based on the STROBE statement.Results:Thirteen studies with 33 398 cases were included, the rate of birth defects using frozen semen was 1.09% (95% CI=0.85%-1.32%), lower than that published by the Chinese Ministry of Health (1.53%, P<0.001). The rate was 1.06% (95% CI=0.78%-1.35%) in artificial insemination by donor (AID), 0.60% (95% CI=0.03%-1.22%) in in vitro fertilization (IVF) and 1.35% (95% CI=0.06%-2.75% ) in intracytoplasmic sperm injection (ICSI), the difference was not statistically significant ( P=0.785). Among the birth defects, the cardiovascular system had the highest rate, followed by the central nervous system and musculoskeletal system and congenital urogenital system and so on. Conclusion:ART with cryopreserved donor sperm does not increase the risk of birth defects. However, more studies with large sample sizes are needed to confirm this conclusion because some papers with low study quality were included in this study.

Objective:To evaluate the incidence of birth defects in offspring using frozen semen from sperm banks by meta-analysis, to provide scientific evidence for the safety and reliability of frozen semen in assisted reproductive technology (ART).Methods:China National Knowledge Infrastructure (CNKI), Wanfang Digital Database (Wanfang), VIP Citation Database (VIP), CBMDisc and PubMed were searched about birth defects using frozen semen in ART since the establishment to October 1, 2019. Literatures were screened according to the predefined inclusion and exclusion criteria and evaluated based on the STROBE statement.Results:Thirteen studies with 33 398 cases were included, the rate of birth defects using frozen semen was 1.09% (95% CI=0.85%-1.32%), lower than that published by the Chinese Ministry of Health (1.53%, P<0.001). The rate was 1.06% (95% CI=0.78%-1.35%) in artificial insemination by donor (AID), 0.60% (95% CI=0.03%-1.22%) in in vitro fertilization (IVF) and 1.35% (95% CI=0.06%-2.75% ) in intracytoplasmic sperm injection (ICSI), the difference was not statistically significant ( P=0.785). Among the birth defects, the cardiovascular system had the highest rate, followed by the central nervous system and musculoskeletal system and congenital urogenital system and so on. Conclusion:ART with cryopreserved donor sperm does not increase the risk of birth defects. However, more studies with large sample sizes are needed to confirm this conclusion because some papers with low study quality were included in this study.

Objective: To investigate the clinical effect of concentrated growth factor (CGF) applied in guided bone regeneration (GBR) for severe bone deficiency in the anterior maxilla. Methods : Forty patients with bone defects in the anterior maxilla were chosen to be treated with GBR, 20 patients were treated with CGF applied in GBR as the observation group, and the other 20 patients were treated only with GBR as the control group. The evaluation of wound healing was performed after the operation, and bone augmentation was evaluated half a year after the operation. Results: The first-stage healing rate of soft tissue wounds in the observation group was 100% and 75% in the control group, and the primary healing rate in the observation group was better than that in the control group (P=0.017). The changes in bone width of the observation group were （3.70 ± 0.28） mm, and those of the control group were （2.96 ± 0.16） mm. The bone augmentation in the observation group was higher than that in the control group (P=0.000). Conclusion CGF applied in GBR has a good effect on bone augmentation for severe bone deficiency in the anterior maxilla.

Objective:To compare the maxillary sinus mucosa's stress distribution when elevated by three lift materials.Methods:Three Finite element models of maxillary sinus mucosa with 0.3 mm thickness elevated by implant,grafting autogenous cancellous bone and hydroxyapatite respectively were established in the specific units.ANSYS finite element analysis software was used to evaluate maxillary sinus mucosa deformation by the simulated closed sinus lift surgery.Differences of Von Mises stress values of mucosa surface were calculated when maxillary sinus mucosa lift height was increased from 1 mm to 5 mm according to the a large deformation theory. Results:The Von Mises stress values on membrane surface elevated by implant,grafting autogenous cancellous bone and hydroxyapa-tite bone substitute materials showed no difference within 5 mm elevation.Conclusion:Closed maxillary sinus floor lifting operation with implant elevating the maxillary sinus membrane directly is a simple and minimally invasive way for sinus floor elevation.

BACKGROUND:How to avoid iatrogenic maxil ary sinus mucosal perforation after closed maxil ary sinus augmentation.
OBJECTIVE:To compare the influence of maxil ary sinus mucosa at different thicknesses on the mucosal perforation in closed maxil ary sinus augmentation operation by using finite element analysis.
METHODS:Three finite element models of maxil ary sinus mucosa at different thicknesses of 0.3 mm, 0.5 mm, 0.8 mm respectively and implant with 4.2 mm diameter were established in the SHELL63 units. ANSYS finite element analysis software was used to evaluate maxil ary sinus mucosal deformation by the simulated closed maxil ary sinus augmentation surgery. Differences of Von Mises maximum stress values of mucosa surface were calculated according to the non-linear large-deformation theory.
RESULTS AND CONCLUSION:When maxil ary sinus mucosa height was increased from 1 mm to 5 mm, the large deformation was observed in the center of mucosa center. The maximum stress curve slope was shifted mild between 1-4 mm deformation, while shifted abruptly after 4 mm. There was no difference in the value of Von Mises maximum stress values between three maxil ary sinus mucosa at 0.3 mm, 0.5 mm, 0.8 mm thickness, when the lift height was increased from 1 mm to 5 mm (P>0.05). Maxil ary sinus mucosa are faced with a higher risk of mucosal perforation and elastic elongation when maxil ary sinus height is increased more than 4 mm. Maxil ary sinus mucosa at 0.3-0.8 mm thickness are faced the similar risk of mucosal perforation in closed maxil ary sinus augmentation operation within 5 mm. While more considerations should be paid on patients with less than 0.3 mm maxil ary sinus mucosa thickness.

Objective To investigate the clinical results of immediate loading of a single anterior implant. Methods 26 implants were placed into anterior sites. Provisional prosthesis were placed at the time of fixture placement. It did not occlude in any pathway. Restoration was for esthetic only, not for function. Results No fixture was lost since the immediate restoration was delivered, the minimum being 12 months and the maximum 72 months. Conclusion Clinical studies on the placement of immediate restoration in anterior implant of maxilla have revealed predictable results.