Magnesium malate-modified calcium phosphate bone cement promotes the repair of vertebral bone defects in minipigs via regulating CGRP.

Active artificial bone substitutes are crucial in bone repair and reconstruction. Calcium phosphate bone cement (CPC) is known for its biocompatibility, degradability, and ability to fill various shaped bone defects. However, its low osteoinductive capacity limits bone regeneration applications. Effectively integrating osteoinductive magnesium ions with CPC remains a challenge. Herein, we developed magnesium malate-modified CPC (MCPC). Incorporating 5% magnesium malate significantly enhances the compressive strength of CPC to (6.18 ± 0.49) MPa, reduces setting time and improves disintegration resistance. In vitro, MCPC steadily releases magnesium ions, promoting the proliferation of MC3T3-E1 cells without causing significant apoptosis, proving its biocompatibility. Molecularly, magnesium malate prompts macrophages to release prostaglandin E2 (PGE2) and synergistically stimulates dorsal root ganglion (DRG) neurons to synthesize and release calcitonin gene-related peptide (CGRP). The CGRP released by DRG neurons enhances the expression of the key osteogenic transcription factor Runt-related transcription factor-2 (RUNX2) in MC3T3-E1 cells, promoting osteogenesis. In vivo experiments using minipig vertebral bone defect model showed MCPC significantly increases the bone volume fraction, bone density, new bone formation, and proportion of mature bone in the defect area compared to CPC. Additionally, MCPC group exhibited significantly higher levels of osteogenesis and angiogenesis markers compared to CPC group, with no inflammation or necrosis observed in the hearts, livers, or kidneys, indicating its good biocompatibility. In conclusion, MCPC participates in the repair of bone defects in the complex post-fracture microenvironment through interactions among macrophages, DRG neurons, and osteoblasts. This demonstrates its significant potential for clinical application in bone defect repair.

A worldwide bibliometric analysis of the research trends and hotspots of bruxism in adults during 1991-2021.

BACKGROUND AND OBJECTIVES: With the increasing attention to bruxism, the research on bruxism is increasing rapidly. However, there is still a lack of systematic bibliometric analysis in the field of bruxism in adults. This study aimed to comprehensively explore and visualize the global trends and research hotspots in the field of bruxism in adults during 1991-2021. METHODS: The study searched the literature published during 1991-2021 in the Web of Science Core Collection database without language restrictions. VOSviewer, CiteSpace and Microsoft Excel were applied to analyse the authors, institutions, journals, countries, cited references, keywords and other information of the included publications, and construct visualized cooperation networks. RESULTS: A total of 878 articles were finally included. The top two most productive authors in the past 30 years were Lobbezoo F and Manfredini D. ACTA-Amsterdam, Univ Sao Paulo, Univ Helsinki, Univ Padua, Univ Montreal, et al. were prominent institutions in this field. Journal of Oral Rehabilitation made outstanding contributions in this field. The United States produced the most documents in this field, followed by Brazil. Both countries and authors cooperated closely around the world. The two most cited articles focused on the definition, assessment and classification of bruxism. In recent years, diagnostic criteria and stress have begun to receive a lot of attention. CONCLUSION: From 1991 to 2021, the attention to bruxism in adults continued to increase. Diagnostic criteria and stress may be potential research hotspots in this field. This study references relevant scholars on development trends and research hotspots.

Parathyroid hormone enhances gap healing and osseointegration in orthopedic porous coated titanium implants: a correlative micro-computed tomographic, histomorphometric and biomechanical analysis.

BACKGROUND: Parathyroid hormone, with its anabolic effect on bone formation, has shown excellent outcomes of curing postmenopausal osteoporosis as well as enhancing osseointegration around orthopaedic and stomatologic implants.The purpose of the present study is to test if low-dose intermittent PTH (1-34) treatment could achieve a satisfactory osseointegration in 2-mm peri-implant gaps, as to provide a new idea for improving the stability of such prosthesis, which will be of great clinical value. METHODS: A custom-made titanium implant was implanted on the calvarium of New Zealand White rabbits. 48 male rabbits were randomly divided into control and PTH group. PTH group received subcutaneous injection of PTH (20 µg/day, 5 days/week). Animals were sacrificed at 4 and 8 weeks after surgery. Quantitative micro-computed tomography, histology and biomechanical pull-out testing were performed to evaluate the gap healing at implantation site. RESULTS: Analysis of micro-computed tomography demonstrated that PTH group achieved more new bone formation in 2-mm gaps and on bone-implant interface. Quantitatively, significant differences were observed between two groups in regard to BIC and BV/TV at each time-point. Histological staining revealed that PTH group had a superiority in trabecular number, thickness, separation and better osseointegration compared to control group. As for biomechanical pull-out testing, PTH group also showed significant improvement of ultimate force than control group. CONCLUSIONS: Low-dose intermittent administration of PTH for 4 and 8 weeks enhances early osseointegration and fixation of orthopedic implants surrounded by a 2-mm gap in terms of increased bone regeneration and mechanical stability. These findings suggest PTH a potential for reducing the postoperative complications of implants by improving bone healing at peri-implant gaps.

Clinical and radiographic outcomes of cervical disc arthroplasty with Prestige-LP Disc: a minimum 6-year follow-up study.

BACKGROUND: Cervical disc arthroplasty (CDA) has been considered as an alternative to cervical arthrodesis in the treatment of cervical degenerative disc diseases (CDDD). The aim of this study was to assess the long-term clinical and radiographic outcomes of CDA with Prestige-LP Disc. METHODS: A total of 61 patients who underwent single- or two-level CDA with Prestige-LP Disc were retrospectively investigated at a minimum of 6-year follow-up. Clinical assessments included visual analogue scale (VAS) for neck and arm pain, Neck Disability Index (NDI), and Japanese Orthopedic Association (JOA) score. Radiological evaluations included range of motion (ROM) of the index and adjacent levels, segmental angle, cervical sagittal alignment, heterotopic ossification (HO) and adjacent segment degeneration (ASD). RESULTS: Significant and maintained improvement in VAS for neck and arm, NDI and JOA were observed after a mean follow-up of 82.3 months (p < 0.001). The preoperative ROM of the index level was 9.7°, which was maintained at 2-and 4-year follow-up (9.3°, p = 0.597; 9.0°, p = 0.297), but was decreased to 8.0° at final follow-up (p = 0.019). Mobility was maintained in 80.5% (62/77) of the implanted prostheses at final follow-up. ROM of the superior and inferior adjacent segments, cervical sagittal alignment and cervical angel were all maintained. The incidence of HO was 42.9% at final follow-up, but it did not influence the clinical outcome. Radiographic ASD were detected in 29.5% of the patients. However, the incidence of symptomatic ASD was only 6.6%. CONCLUSION: Cervical disc arthroplasty with Prestige-LP Disc demonstrated a maintained and satisfactory clinical outcome at a minimal of 6-year follow-up, with majority of the prostheses remained mobile. Cervical disc arthroplasty with Prestige-LP Dis can be considered as an effective surgical method in treating CDDD.

Decellularized Brain Extracellular Matrix Hydrogel Aids the Formation of Human Spinal-Cord Organoids Recapitulating the Complex Three-Dimensional Organization.

The intricate electrophysiological functions and anatomical structures of spinal cord tissue render the establishment of in vitro models for spinal cord-related diseases highly challenging. Currently, both in vivo and in vitro models for spinal cord-related diseases are still underdeveloped, complicating the exploration and development of effective therapeutic drugs or strategies. Organoids cultured from human induced pluripotent stem cells (hiPSCs) hold promise as suitable in vitro models for spinal cord-related diseases. However, the cultivation of spinal cord organoids predominantly relies on Matrigel, a matrix derived from murine sarcoma tissue. Tissue-specific extracellular matrices are key drivers of complex organ development, thus underscoring the urgent need to research safer and more physiologically relevant organoid culture materials. Herein, we have prepared a rat decellularized brain extracellular matrix hydrogel (DBECMH), which supports the formation of hiPSC-derived spinal cord organoids. Compared with Matrigel, organoids cultured in DBECMH exhibited higher expression levels of markers from multiple compartments of the natural spinal cord, facilitating the development and maturation of spinal cord organoid tissues. Our study suggests that DBECMH holds potential to replace Matrigel as the standard culture medium for human spinal cord organoids, thereby advancing the development of spinal cord organoid culture protocols and their application in in vitro modeling of spinal cord-related diseases.

Human Placenta Decellularized Extracellular Matrix Hydrogel Promotes the Generation of Human Spinal Cord Organoids with Dorsoventral Organization from Human Induced Pluripotent Stem Cells.

Spinal cord organoids are of significant value in the research of spinal cord-related diseases by simulating disease states, thereby facilitating the development of novel therapies. However, the complexity of spinal cord structure and physiological functions, along with the lack of human-derived inducing components, presents challenges in the in vitro construction of human spinal cord organoids. Here, we introduce a novel human decellularized placenta-derived extracellular matrix hydrogel (DPECMH) and, combined with a new induction protocol, successfully construct human spinal cord organoids. The human placenta-sourced decellularized extracellular matrix (dECM), verified through hematoxylin and eosin staining, DNA quantification, and immunofluorescence staining, retained essential ECM components such as elastin, fibronectin, type I collagen, laminin, and so forth. The temperature-sensitive hydrogel made from human placenta dECM demonstrated good biocompatibility and promoted the differentiation of human induced pluripotent stem cell (hiPSCs)-derived spinal cord organoids into neurons. It displayed enhanced expression of laminar markers in comparison to Matrigel and showed higher expression of laminar markers compared to Matrigel, accelerating the maturation process of spinal cord organoids and demonstrating its potential as an organoid culture substrate. DPECMH has the potential to replace Matrigel as the standard additive for human spinal cord organoids, thus advancing the development of spinal cord organoid culture protocols and their application in the in vitro modeling of spinal cord-related diseases.

Bibliometric Analysis of Research on Temporomandibular Joint and Occlusion from 2000 to 2022.

Purpose: This study conducted a bibliometric analysis that comprehensively described publications on temporomandibular joint and occlusion from 1 January 2000 to 31 October 2022, aiming to reveal hotspots and predict future research trends. Methods: A total of 2985 articles and reviews were retrieved from Web of Science Core Collection (WoSCC). Excel 2019, VOSviewer and CiteSpace software were used for visualizing analysis of research trends, authors, journals, institutions, countries, keywords and cited references. Results: Both the annual publication counts and citation times increased significantly. Wang MQ was the most active author. Moreover, Manfredini D and Okeson JP were the most influential two. Journal of Oral Rehabilitation was the core journal. University of Sao Paulo was the most productive institutions. "Temporomandibular disorders" (TMDs), "temporomandibular joint" and "occlusion" were the top 3 keywords with the most frequencies. Keywords and references with burst showed that the causes of TMDs, diagnosis and treatments for TMDs as well as bruxism may be hotspots currently and in the future. Conclusion: In this study, the research trends, the most productive and influential authors, journals, institutions, countries, in addition to keywords and cited references with burst in the field of temporomandibular joint and occlusion were revealed by a bibliometric analysis, which could help scholars to understand recent hotspots and future trends.

Imaging study on the relationship between anterior and posterior occlusal planes and temporomandibular osteoarthrosis.

OBJECTIVES: The aim of this study was to compare the anterior and posterior occlusal plane characteristics of patients with different temporomandibular joint osseous statuses. METHODS: A total of 306 patients with initial cone beam CT (CBCT) and cephalograms were included. They were divided into three groups on the basis of their temporomandibular joint osseous status: bilateral normal (BN) group, indeterminate for osteoarthrosis (I) group, and osteoarthrosis (OA) group. The anterior and posterior occlusal planes (AOP and POP) of the different groups were compared. Then, the regression equation was established after adjusting for confounding factors, and a correlation analysis between the occlusion planes and other parameters was performed. RESULTS: SNA, SNB, FMA, SN-MP, Ar-Go, and S-Go were correlated with the occlusal planes. Relative to the BN and I groups, the FH-OP of the OA group increased by 1.67° on the average, FH-POP increased by 1.42° on the average, and FH-AOP increased by 2.05° on the average. CONCLUSIONS: The occlusal planes were steeper in the patients with temporomandibular osteoarthrosis than in the patients without it, and the mandible rotated downward and backward. The height of the mandibular ramus, the mandibular body length, and the posterior face height were small. In clinical practice, attention should be given to the potential risk of temporomandibular joint osteoarthrosis in such patients. In addition, SNB, FMA, SN-MP, Ar-Go, S-Go, and occlusal planes had moderate correlations.

The relationship between perfectionism, self-perception of orofacial appearance, and mental health in college students.

Background: In dental clinical practice, self-perception of orofacial appearance is highly correlated with treatment satisfaction. Therefore, it is important to explore factors correlated with self-perception of orofacial appearance. Perfectionism may be one such factor. This study investigated the role of perfectionism in self-perception of orofacial appearance. Methods: Participants completed an online questionnaire that included demographic data, a measure of perfectionism, a measure of self-perception of orofacial appearance (including body image, smile appearance concern, and self-esteem), and a measure of anxiety and depression. Results: High perfectionism scores significantly predicted greater age, body image, smile appearance concern, and mental health scores and lower self-esteem scores (p < 0.005). After adjusting for possible confounding variables, smile appearance concern largely disappeared. Mental health acted as a mediator in the relationships between perfectionism and three orofacial appearance characteristics. Conclusion: High perfectionism predicted higher self-perception of body image, and lower mental health and self-esteem in college students. Mental health could mediate the relationships between perfectionism and self-perception of orofacial appearance.

The association between problematic smartphone use and the severity of temporomandibular disorders: A cross-sectional study.

Objective: To evaluate the prevalence of different types of temporomandibular disorders (TMD) symptoms in young adults and determine their associations with problematic smartphone use (PSU). Methods: The data of the study were collected from local university students through an online questionnaire survey. Demographic information, Fonseca Anamnestic Index (FAI), Smartphone Addiction Scale-Short Version (SAS-SV), and Patient Health Questionnaire-4 (PHQ-4) responses were gathered electronically and analyzed using multiple logistic regression analysis. Results: There were 163 male and 307 female respondents were participated in this study. The prevalence of PSU and TMD were 83.6% and 66.4%, respectively. There was a moderate statistical correlation between PSU and TMD among young adults (r = 0.31, p < 0.01). The logistic regression model revealed that the risk of TMD was 1.77 times higher in people with PSU than in those without PSU (OR = 1.77; 95% CI 1.04-3.06). PSU is a risk factor for pain-related TMD (OR = 1.81; 95% CI 1.08-3.04) but not intra-articular TMD. Conclusion: Subjects showed high prevalence of both TMD and PSU. People with PSU experienced more severe and frequent pain-related rather than intra-articular TMD symptoms than those without PSU. By reducing the problematic smartphone use, the risk factor of TMD might be avoided.

[Effects of calcium phosphate cement combined with hyaluronic acid/curcumin on the proliferation and osteogenesis of osteoblasts].

OBJECTIVE: After using hyaluronic acid (HA) to modify curcumin (CUR), the effects of calcium phosphate cement (CPC) combined with HA/CUR on the proliferation and osteogenesis of osteoblasts were investigated. METHODS: First, HA and CUR were esterified and covalently combined to prepare HA/CUR, and the characteristics were observed and the infrared spectrum was tested. Then, HA, CUR, and HA/CUR were mixed with CPC according to 5% ( W/ W) to prepare HA-CPC, CUR-CPC, and HA/CUR-CPC, respectively. Setting time detection, scanning electron microscope observation, injectable performance test, and compression strength test were conducted; and the CPC was used as a control. Osteoblasts were isolated and cultured from the skull of newborn Sprague Dawley rats, and the 2nd generation cells were cultured with the 4 types of bone cement, respectively. The effects of HA/CUR-CPC on the proliferation and osteogenesis of osteoblasts were estimated by the scanning electron microscopy observation, live/dead cell fluorescence staining, cell counting, osteopontin (OPN) immunofluorescence staining, alkaline phosphatase (ALP) staining,and alizarin red staining. RESULTS: Infrared spectroscopy test showed that HA and CUR successfully covalently combined. The HA/CUR-CPC group had no significant difference in initial setting time, final setting time, injectable rate, and compressive strength when compared with the other 3 groups ( P>0.05); scanning electron microscope observation showed that HA/CUR was scattered on CPC surface. After co-culture of bone cement and osteoblasts, scanning electron microscopy observation showed that the osteoblasts, which had normal morphology and the growth characteristics of osteoblasts, clustered and adhered to HA/CUR-CPC. There was no significant difference in cell survival rate between HA/CUR-CPC group and other groups ( P>0.05), and the number of cells significantly increased ( P<0.05); the degrees of OPN immunofluorescence staining, ALP staining, and alizarin red staining were stronger than other groups. CONCLUSION: HA/CUR-CPC has good biocompatibility and mechanical properties, which can promote the proliferation and osteogenesis of osteoblasts.

A Comparison of Cervical Disc Arthroplasty and Anterior Cervical Discectomy and Fusion in Patients with Two-Level Cervical Degenerative Disc Disease: 5-Year Follow-Up Results.

OBJECTIVE: To present a long-term clinical and radiographic comparison between the Prestige LP cervical disc replacement and the Zero-P spacer cervical disc fusion in the treatment of patients with symptomatic 2-level cervical degenerative disease. METHODS: In total, 36 patients in the anterior cervical discectomy and fusion (ACDF) group and 24 patients in the cervical disc arthroplasty (CDA) group were analyzed before surgery and at 1 week and 3, 6, 12, 24, and 60 months after surgery. Clinical assessments included the Japanese Orthopaedic Association score, visual analog scale, and Neck Disability Index scores. Radiographic assessments included cervical lordosis, range of motion (ROM) of the total cervical spine, functional spinal unit (FSU), and superior and inferior adjacent segments. Complications including heterotopic ossification and adjacent-segment degeneration (ASD) at 5-year follow-up were collected as well. RESULTS: Mean follow-up period was 65.6 months. Both the ACDF and CDA groups showed significant clinical improvements in terms of Japanese Orthopaedic Association score, visual analog scale, and Neck Disability Index (P < 0.05), but there was no significant difference between groups at the last follow-up period. A significant increase of cervical lordosis was observed in the CDA group after surgery whereas a significant difference was not observed between groups. ROM of the total cervical spine and FSU were maintained during the follow-up, and a significant decrease was observed in the ACDF group after surgery (P < 0.05). The ROM of the superior adjacent segment did not show any difference whereas the ROM of the inferior adjacent segment in the ACDF group presented a significant increase at 6 months and 1 year after surgery and a significant decrease at the last follow-up period. A total of 8 (33.3%) patients in the CDA group had an occurrence of heterotopic ossification. ASD was observed in 2 (8.3%) patients who underwent CDA surgery and 8 (22.2%) patients who underwent ACDF surgery. CONCLUSIONS: The use of the Prestige-LP and ZERO-P Spacer implantations is safe and effective. At 5 years after surgery, CDA with Prestige-LP is superior in terms of ROM of the total cervical spine, FSU, and inferior adjacent segment. It also has a relatively low occurrence rate of ASD. This procedure may be a suitable choice for the treatment of contiguous 2-level CDDD.

Influence of Fusion on the Behavior of Adjacent Disc Arthroplasty in Contiguous 2-Level Hybrid Surgery In Vivo.

OBJECTIVE: To investigate whether the behavior of disc arthroplasty in 2-level hybrid surgery (HS) was affected by adjacent fusion in vivo compared with cervical disc arthroplasty (CDA) alone. METHODS: Seventy-nine patients undergoing either a 1-level CDA or contiguous 2-level HS were retrospectively reviewed. Radiologic assessments included segmental lordosis (SL), intervertebral disc height (IDH), changes in SL and IDH, range of motion (ROM) of the disc replacement and its adjacent segments, migration and subsidence of the prosthesis, heterotopic ossification (HO), and adjacent segment degeneration (ASD) adjacent to the arthroplasty level. Clinical features and outcome scores were also recorded. RESULTS: Compared with 1-level CDA, the increased SL and IDH immediately after surgery in 2-level HS were more likely to be lost throughout the follow-up period. However, both groups generally maintained the SL and IDH of the arthroplasty segment postoperatively. Two-level HS did not exhibit hypermobility of the disc prosthesis and preserved preoperative ROM of the adjacent segment of the device. The HS group showed adverse effects on the prosthesis stability, but there was no significant difference in the number of cases of obvious migration or subsidence between the groups. The differences in HO, ASD, and clinical outcomes between the groups were not significant at the final follow-up. CONCLUSIONS: Although the fusion in 2-level HS partially affected the behavior of adjacent disc arthroplasty compared with CDA alone, it did not cause severe complications and adverse clinical outcomes. However, large-scale and long follow-up trials are warranted.

Incidence of dysphagia and dysphonia after Hangman's fractures: Evidence from 93 patients.

This research aims to explore the accurate incidence, severity and outcomes of dysphagia and dysphonia after Hangman fractures.A total of 93 patients were included in this study and clinical data were reviewed. The Bazaz grading system (0-None; 1-Mild; 2-Moderate; 3-Severe) was used for dysphagia evaluation and the Voice Handicap Index-10 used to evaluate dysphonia. In all of the patients, evaluation of dysphagia and dysphonia was performed preoperatively and at 1 week, 1 month, 3, 6, and 12 months after surgery. SPSS 22.0 software (SPSS Inc, Chicago, IL) was used for all statistical analyses.Posttraumatic immediate dysphagia was found in 8 patients and posttraumatic immediate dysphonia was observed in 3 patients. The incidence of dysphagia was 22.6% at the 1st week, 16.1% at the 1st month, and 9.7% at the 3rd month of follow-up. The incidence of dysphonia was 24.5% at the 1st week, 11.3% at the 1st month, and 3.8% at the 3rd month of follow-up.Posttraumatic immediate dysphagia and dysphonia occurred and the anterior surgical approach was associated with a higher incidence of dysphagia compared to posterior surgery and nonoperative patients. Most dysphagia and dysphonia were mild and gradually decreased during the subsequent 3 months after surgery. Future prospective, randomized studies with larger sample sizes are required to validate these data.

Cervical disc arthroplasty with Prestige-LP for the treatment of contiguous 2-level cervical degenerative disc disease: 5-year follow-up results.

The objective of this study is to present the long-term results and to evaluate the safety and effectiveness of the Prestige-LP cervical disc replacement in treatment of patients with symptomatic 2-level cervical degenerative disc disease.Twenty-four patients with 48 Prestige-LP disc were analyzed before surgery and at 1 week, 3 months, 6 months, 12 months, 24 months, and 60 months after surgery. Clinical assessments included 36-Short Form (SF-36), Japanese Orthopedic Assessment (JOA), visual analog scale (VAS), and Neck Disability Index (NDI) scores. Radiographic assessments included cervical lordosis (CL), disc height (DH), range of motion (ROM) of the total cervical spine, functional spinal unit (FSU) as well as upper and lower operated segment. Complications at the 5-year follow-up were collected as well.Mean follow-up period was 64.22 months. There was clinical improvement in terms of SF-36, JOA, NDI, and VAS from the preoperative to the final follow-up (P < .05). Overall, ROM of the total cervical spine, FSU, and upper and lower operated segment were maintained during the follow-up. Statistically significant (P < .05) improvements in the trend of CL and DH were noted at the follow-up. Eight patients were observed an appearance of heterotopic ossification at the 5-year follow-up, with 6 patients appeared at Class II and 2 patients at Class III. Adjacent segment degeneration assessed by radiographic evidence was found in 2 patients.Two-level cervical disc arthroplasty with Prestige-LP showed significant improvement in clinical outcomes at 5 years. It not only effectively preserves the motion of both total cervical spine and operated segments, but also restores normal CL and DH up to 5 years postoperation.