OBJECTIVE: To investigate the biocompatibility of porous WE43 magnesium alloy scaffolds manufactured by 3D printing technology and to observe its effect in treating femoral defects in New Zealand white rabbits. METHODS: In vitro cytotoxicity test was performed using bone marrow mesenchymal stem cells from Sprague Dawley (S-D) rats. According to the different culture media, the cells were divided into 100% extract group, 50% extract group, 10% extract group and control group. After culturing for 1, 3 and 7 days, the cell activity of each group was determined by cell counting kit-8 (CCK-8). In the in vivo experiment, 3.0-3.5 kg New Zealand white rabbits were randomly divided into three groups: Experimental group, bone cement group and blank group, with 9 rabbits in each group. Each rabbit underwent surgery on the left lateral femoral condyle, and a bone defect with a diameter of 5 mm and a depth of 6 mm was created using a bone drill. The experimental group was implanted with WE43 magnesium alloy scaffolds, the bone cement group was implanted with calcium sulfate bone cement, and the blank group was not implanted. Then 4, 8 and 12 weeks after surgery, 3 rabbits in each group were euthanized by carbon dioxide anesthesia, and the femur and important internal organs were sampled. Micro-computed tomography (Micro-CT) scanning was performed on the left lateral femoral condyle. Sections of important internal organs were prepared and stained with hematoxylin-eosin (HE). Hard tissue sections were made from the left lateral femoral condyle and stained with methylene blue acid fuchsin and observed under a microscope. RESULTS: In the cytotoxicity test, the cell survival rate in the 100% extract group was higher than that in the control group (140.56% vs. 100.00%, P < 0.05) on 1 day of culture; there was no statistically significant difference (P>0.05) in cell survival rate among the groups on 3 days of culture; the cell survival rate in the 100% extract group was lower than that in the control group (68.64% vs. 100.00%, P < 0.05) on 7 days of culture. Micro-CT scanning in the in vivo experiment found that most of the scaffolds in the experimental group had been degraded in 4 weeks, with very few high-density scaffolds remaining. In 12 weeks, there was no obvious stent outline. In 4 weeks, a certain amount of gas was generated around the WE43 magnesium alloy scaffold, and the gas was significantly reduced from 8 to 12 weeks. Hard tissue sections showed that a certain amount of extracellular matrix and osteoid were generated around the scaffolds in the experimental group in 4 weeks. In the bone cement group, most of the calcium sulfate bone cement had been degraded. In 8 weeks, the osteoid around the scaffold and its degradation products in the experimental group increased significantly. In 12 weeks, new bone was in contact with the scaffold around the scaffold in the experimental group. There was less new bone in the bone cement group and the blank group. CONCLUSION The porous WE43 magnesium alloy scaffold fabricated by 3D printing process has good biocompatibility and good osteogenic properties, and has the potential to become a new material for repairing bone defects.
Animals ; Rabbits ; Printing, Three-Dimensional ; Alloys/chemistry* ; Tissue Scaffolds/chemistry* ; Magnesium/chemistry* ; Rats, Sprague-Dawley ; Biocompatible Materials ; Mesenchymal Stem Cells/cytology* ; Femur/surgery* ; Rats ; Absorbable Implants ; Male ; Bone Regeneration ; Tissue Engineering/methods* ; Cells, Cultured

OBJECTIVE: To observe the long-term health condition of the single-tooth dental implant at the first molar site, and to evaluate the related factors affecting the peri-implant health. METHODS: In this study, 82 patients who were treated in the Second Clinical Division, Peking University School and Hos-pital of Stomatology from January 2008 to December 2020 were enrolled. Peri-implant tissue conditions were assessed by clinical and radiographic examination. The peri-implant probing depth (PPD), modified sulcus bleeding index (mSBI), modified plaque index (mPLI) and papilla index (PI) were recorded for 278 implants. The X-ray analysis included the restoration emergence angle (REA), the clinical crown-implant ratio (cC/I), the horizontal tooth-implant distance (HTID), the contact point level (CPL) and the embrasure surface area (ESA), etc. Kruskal-Wallis rank sum test and generalized estimation equation were used for statistical analysis. RESULTS: The average age of the patients was (40.2±9.5) years (19 to 84 years), with 33 males and 49 females. The follow-up time was (4.9±3.3) years (1 to 10 years). According to the diagnostic criteria in 2018, the prevalence of peri-implantitis in this study was 14.03% on the implant level and 21.95% on the patient level. The peri-implant health rate was 19.06% on the implant level and 18.29% on the patient level. The prevalence of peri-implant mucositis was 66.91% on the implant level and 59.75% on the patient level. At the baseline, there were statistically significant differences between the peri-implant health group and peri-implantitis group in PPD, distal HTID and mesial/distal CPL, cC/I (P < 0.05), while there was no statistically significant difference in mSBI, mPLI, PI, mesial HTID, mesial/distal REA and mesial/distal ESA between the two groups. Among the differences between follow-up and baseline, there were statistically significant dif-ferences between the two groups in PPD, mesial/distal HTID, mesial/distal CPL and mesial/distal ESA (P < 0.05). Generalized estimation equation showed that PPD, mesial/distal HTID, mesial CPL, and mesial ESA had significant positive correlations with the risk of peri-implantitis in the difference between baseline and follow-up. CONCLUSION Based on the results of this study, the peri-implant health rate is still unsatisfied, and the PPD, HTID, CPL, ESA may be related to the long-term health of the implant.
Humans ; Male ; Female ; Middle Aged ; Adult ; Dental Implants, Single-Tooth/adverse effects* ; Aged ; Aged, 80 and over ; Periodontal Index ; Young Adult ; Peri-Implantitis/epidemiology*

OBJECTIVE: To assess the osteogenesis height in maxillary sinus segment one year after zygomatic implantation by imaging methods, and evaluate the influence of patient factors, maxillary sinus anatomical factors and surgical factors on postoperative osteogenesis height. METHODS: This study is a retrospective study, including patients who underwent zygomatic implantation and whose zygomatic implants passed through the maxillary sinus at the Department of Implantology, Peking University School and Hospital of Stomatology from July 2017 to January 2022. Preoperative and postoperative cone beam CT (CBCT)was taken to measure and calculate the average osteogenesis height (AOH) in maxillary sinus segment of the zygomatic implants, then the residual bone height, the width and morphology of the maxillary sinus floor in the buccal and palatal directions were measured. Besides, the integrity of Schneiderian membrane during implant surgery, and the general information of the patients and zygomatic implants were recorded. By comparing anatomical situations and surgical characteristics, the differences of AOH under different conditions were analyzed. Then AOH was divided into two groups (obvious osteogenesis group and non-obvious osteogenesis group) using the median as the threshold, and the influencing factors of osteogenesis were evaluated using mixed effect generalized linear model univariable and multivariable analysis. RESULTS: A total of 47 zygomatic implants were implanted in 24 patients. During the average follow-up period of 12.1 months, there was no implant failure, and the implant survival rate was 100%. Postoperative CBCT showed that 43 zygomatic implants had osteogenic images in the maxillary sinus segment, most of which originated from the floor of the maxillary sinus, and the median AOH was 3.1 mm [interquartile range (IQR): 4.0 mm]. In terms of maxillary sinus width, there were 31 cases (66.0%) of wide type and 16 cases (34.0%) of narrow type. In the aspect of buccal and palatal morphology, 17 cases were taper (36.2%), 20 cases were round (42.6%), and 10 cases were flat (21.3%). The median of residual bone height was 2.8 mm (IQR: 2.2 mm) before operation. Univa-riate analysis of mixed effect generalized linear model showed that postoperative obvious osteogenic rate was related to the residual bone height (OR=2.09, P=0.006). Multivariate analysis showed that the resi-dual bone height (OR=2.55, P=0.022) and the shape of a taper maxillary sinus (OR=11.44, P=0.040) had a significant impact on the postoperative obvious osteogenic rate. CONCLUSION The maxillary sinus floor showed osteogenic images 1 year after the zygomatic implantation surgery. Larger residual bone height and the shape of a taper maxillary sinus may be favorable factors for osteogenesis.
Humans ; Maxillary Sinus/surgery* ; Cone-Beam Computed Tomography ; Retrospective Studies ; Zygoma/diagnostic imaging* ; Male ; Female ; Osteogenesis/physiology* ; Middle Aged ; Adult ; Dental Implants ; Aged ; Dental Implantation, Endosseous/methods*

Cleaning process validation is an important guarantee for implantable medical devices to ensure product cleanliness. In the manufacturing process, implantable devices usually need to control pollution through cleaning process to achieve a certain cleanliness to ensure the effectiveness of sterilization and product safety. This paper discusses the cleaning process validation of the manufacturing process of the implantable devices based on relevant regulations and technical standards, and proposes the influencing factors and principles to be considered in the cleaning process validation, so as to provide technical reference for the design of the cleaning process validation.
Prostheses and Implants ; Sterilization ; Equipment and Supplies

Cochlear nerve deficiency（CND） is a rare inner ear malformation characterized by a hypoplastic or absent cochlear nerve, resulting in variable hearing loss or total deafness, depending on the quantity of nerve fibers present. About 18% of congenital hearing loss are associated with CND. It is a disease of uncertain cause. The outcome of auditory implant in CND patients varies widely. This article will discuss the related issues of CND.
Humans ; Cochlear Nerve/abnormalities* ; Cochlear Implants ; Child ; Cochlear Implantation/methods* ; Deafness ; Hearing Loss

Objective:This study aims to investigate the perception of Mandarin aspirated and unaspirated consonants by children with cochlear implants （CIs） under quiet and noisy conditions. It also examines factors that may affect their acquisition, such as auditory conditions, place of articulation, manner of articulation, chronological age, age at implantation, and non-verbal intelligence. Methods:Twenty-eight CI children aged 3 to 5 years who received implantation from 2018 to 2023 were recruited. Additionally, 88 peers with normal hearing （NH） were recruited as controls. Both groups participated in a perception test for aspirated/unaspirated consonants under quiet and noisy conditions, along with tests for speech recognition, speech production, and non-verbal intelligence. The study analyzed the effects of group （CI vs. NH）, auditory condition, and consonant characteristics on children's perception of aspirated/unaspirated consonants in Mandarin, as well as the factors contributing to CI children's acquisition of these consonants. Results:①CI children's ability to perceive aspirated/unaspirated consonants was significantly poorer than that of their NH peers （χ²= 14.16, P<0.01）, and their perception accuracy was influenced by the acoustic features of consonants （P<0.01）; ②CI children's consonant perception abilities were adversely affected by noise （P<0.01）, with accuracy in noisy conditions particularly influenced by the manner of articulation （P<0.05）; ③The age at implantation significantly affected CI children's ability to perceive aspirated/unaspirated consonants （β= -0.223, P=0.012）, with earlier implantation associated with better performance. Conclusion:It takes time for CI children to acquire Mandarin aspirated/unaspirated consonants, and early implantation shows many advantages, especially for the perception ability of fine speech features.
Humans ; Cochlear Implants ; Child, Preschool ; Speech Perception ; Cochlear Implantation ; Male ; Female ; Language

Objective:Over the past decades, minimally invasive cochlear implantation（CI） have achieved significant advancements, evolving from initial emphasis on incision miniaturization to comprehensive strategies for preserving intracochlear structures and functions, as well as optimizing overall minimally invasive surgical procedure. However, current academic debates persist regarding standardized definitions and consensus on technical protocols. Future research should prioritize innovations in surgical-assistive robots, refinement of hidden cochlear implant, and exploration of drug deliver electrodes. These efforts aim to advance surgical methodologies toward enhanced minimally invasive approaches, functional preservation, and personalized therapeutic interventions.
Humans ; Cochlear Implantation/trends* ; Minimally Invasive Surgical Procedures/trends* ; Cochlear Implants

Objective:To evaluate the perioperative safety and long-term complications of simultaneous bilateral cochlear implantation（BCI） in young infants, providing reference data for clinical BCI in young children. Methods:Seventy-four infants aged 6-23 months with congenital severe to profound sensorineural hearing loss who were candidates for cochlear implantation at the Department of Otolaryngology, Chinese PLA General Hospital between August 2018 and August 2019 were consecutively enrolled. Parents made the decision to implant either unilaterally or bilaterally. Participants were divided into unilateral cochlear implantation（UCI） group（before and after 12 months of age） and simultaneous BCI group（before and after 12 months of age）. Safety indicators, including perioperative risk variables, complications, and other postoperative adverse events were monitored, with complications followed up for 5-6 years. Comparisons were made between the BCI and UCI, as well as between implantation before and after 12 months of age regarding perioperative safety and long-term complications. Results:A total of 40 BCI patients（23 before 12 months, 17 after 12 months） and 34 UCI patients（20 before 12 months, 14 after 12 months） were included in the study. Regarding perioperative risk variables, the BCI group showed significantly longer anesthesia duration, operative time, and greater blood loss compared to the UCI group, though less than twice that of the UCI group; no anesthetic complications occurred in either group; and there was no significant difference in postoperative hospital stay between the groups. Regarding surgical complications during the 5-year follow-up period, the BCI group experienced 7 complications（2 major, 5 minor）, while the UCI group had 7 complications（1 major, 6 minor）, with no statistical differences between groups. Regarding other postoperative adverse events, the BCI group demonstrated significantly higher total adverse event rates than the UCI group（80.0% vs 38.2%）, with higher rates of moderate to severe anemia（60.0% vs 20.6%） and lower mean hemoglobin levels[（92.35±12.14） g/L vs（102.39±13.09） g/L]. No significant differences were found in postoperative fever rates（50.0% vs 52.9%） or C-reactive protein levels between groups. Within the BCI group, patients implanted before 12 months indicated notably higher rates of total adverse events（91.3% vs 64.7%）, high fever（26.1% vs 0）, and moderate to severe anemia（78.3% vs 35.3%） compared to those implanted after 12 months. Conclusion:Simultaneous BCI in young children under 2 years of age demonstrates controllable overall risks. Compared to UCI, while it shows no increase in anesthetic or surgical complications, it presents higher perioperative risks and adverse event rates, especially in patients implanted before 12 months of age, warranting special attention from medical staff.
Humans ; Cochlear Implantation/methods* ; Infant ; Postoperative Complications ; Hearing Loss, Sensorineural/surgery* ; Follow-Up Studies ; Male ; Perioperative Period ; Female ; Cochlear Implants

Objective:The aim of this study was to present an institution's experience with cochlear reimplantation（CRI）, to assess surgical challenges and post-operative outcomes and to increase the success rate of CRI. Methods:We retrospectively evaluated data from 76 reimplantation cases treated in a tertiary center between 2001 and 2022. Clinical features include caused of CRI, type of failure, surgical issues, and auditory speech performance were analyzed. Categorical Auditory Performance （CAP） and Speech Intelligibility Rating （SIR） scores were used to evaluate pre-and post-CRI outcomes. Our center's consecutive cohort of 1 126 patients had seven patients, while 69 patients were from other cochlear implant centers. Device failure was the most common cause of CRI（68/76）, with the remaining cases including flap complications（3/76）, magnet displacement（3/76）, secondary meningitis（1/76）, and foreign bodies around the implant（1/76）. Postoperative auditory and speech outcome improved in 31.6%（24/76） of patients, remained unchanged in 63.2%（48/76）, and decreased in CAP and SIR scores in 5.2%（4/76） of patients. Postoperatively, the seven patients with cochlear ossification and fibrosis scored lower on the overall CAP and SIR scale than non-ossification individuals, which is a significant factor in surgical success rates and auditory-speech outcomes. Conclusion:CRI surgery is a challenging but relatively safe procedure, and most reimplanted patients experience favorable postoperative outcomes. Medical complications and intracochlear damage are the main causes of poor postoperative results. Therefore, minimally invasive CI has a positive significance for reducing the difficulty of CRI surgery and improving the CI performance.
Humans ; Cochlear Implantation/methods* ; Retrospective Studies ; Cochlear Implants ; Male ; Female ; Postoperative Period ; Treatment Outcome ; Adult ; Speech ; Middle Aged ; Postoperative Complications ; Replantation ; Cochlea/surgery*

Objective:To investigate the application value of intraoperative electrocochleography（ECochG） monitoring technique and insertion techniques in cochlear implant（CI） and analyze its relationship with postoperative residual hearing（RH） preservation. Methods:Thirty-one patients（35 ears） who received CI in our hospital from June 2022 to July 2024 were enrolled. The Advanced Bionics Active Insertion Monitoring（AIM） system was used for real-time ECochG monitoring during surgery. Intraoperative cochlear microphonics （CM） waveform changes were recorded and analyzed in relation to postoperative RH preservation. Results:①ECochG recordings were successfully obtained in 34 of 35 ears （97.1%）. ②According to Harris classification, there were 7 ears（20.6%） of Type A（rising）, 7 ears（20.6%） of Type C（declining）, 8 ears（23.5%） of Type CC（fluctuating）, and 12 ears（35.3%） of Type D（no response）. ③The total CM amplitude decrease was significantly moderately correlated with postoperative low-mid frequency hearing loss（r=0.67, P=0.017）. The total CM amplitude decrease was significantly moderately correlated with postoperative low frequency hearing loss（r=0.65, P=0.023）. ④For the mean amplitude variation, the Amax was 30.70 μV, the Amin was 8.64 μV, and the Aend was 18.27 μV. ⑤Sixteen cases completed postoperative follow-up, with an average low-mid frequency（125-1 000 Hz） residual hearing loss of 15.25 dB HL and a RH preservation rate of 87.5%. Conclusion:Intraoperative ECochG monitoring can effectively predict postoperative residual hearing changes, effectively guide surgical manipulation, and improve residual hearing preservation rate.
Humans ; Cochlear Implantation/methods* ; Audiometry, Evoked Response ; Cochlear Implants ; Male ; Female ; Adult ; Middle Aged ; Monitoring, Intraoperative ; Adolescent ; Young Adult ; Minimally Invasive Surgical Procedures ; Child ; Aged ; Postoperative Period