Synovial osteoclastogenesis mediated by chondrocyte-secreted TNFα promotes TMJ condylar resorption.

BACKGROUND: Insufficient occlusal support (IOS) frequently causes subchondral bone absorption in temporomandibular joint osteoarthritis, and the underlying mechanism requires further investigation. METHODS: An IOS model was established by abrading rat molars. Micro-computed tomography was used to evaluate subchondral bone changes. Osteoclastogenesis of synovium-derived macrophages (SDMs) was confirmed by TRAP staining. Cartilage-specific TNFα depletion was achieved by intra-articular injection of adeno-associated virus carrying shRNA against murine TNFα under control of collagen type II. In vitro, chondrocytes were mechanically compressed and conditioned medium (CM) was collected to detect its ability to induce osteoclastogenesis of SDMs. RESULTS: Synovial osteoclastogenesis and condyle resorption were observed following IOS. TNFα level was elevated in hypertrophic chondrocytes after IOS. Synovial Wnt5a level increased, but Wnt3a level decreased after IOS. Depletion of TNFα in chondrocytes alleviated the synovial osteoclastogenesis and condyle bone resorption. In vitro compression of chondrocytes potentiated TNFα expression and secretion. The CM promoted osteoclastogenesis of SDMs, which were partially prohibited by TNFα neutralizing antibody. Furthermore, inhibition of Wnt3a facilitated osteoclastogenesis, whereas inhibition of Wnt5a partially suppressed osteoclastogenesis, of SDMs cultured in CM. CONCLUSION: Chondrocyte-secreted TNFα induced by IOS is a critical regulator of synovial osteoclastogenesis and subsequent condylar resorption, partially through non-canonical Wnt5a pathway.

Periodontal disease and cognitive deficits: A systematic review and meta-analysis

@#Background: Previous studies showed controversial findings for correlation of periodontal disease and cognitive deficits. Methods: We searched systematically for studies pertaining to correlation of periodontal disease and cognitive deficits published between August 1980 and December 2019 on Web of Science and PubMed. We combined the data extracted from the included studies to determine the correlation between periodontal disease and cognitive deficits. Results: Our analysis indicated a higher risk of cognitive deficits in those with moderate to severe periodontal disease when compared to those with mild or no periodontal disease (odds ratio (OR) = 1.38 (95% confidence intervals (CI): 1.28-1.48). Subgroup analysis showed significant correlations in only case-control and cohort studies (case-control studies: OR = 1.49 (95% CI: 1.24-1.80); cohort studies: relative risk (RR) = 1.33 (95% CI: 1.22-1.45)). Subgroup analysis also indicated that moderate to severe periodontal disease was correlated to increased dementia and Alzheimer disease risks, whereas no significant correlation was found between periodontal disease and mild cognitive impairment (dementia: OR/RRs = 1.32 (95% CI: 1.22-1.44); Alzheimer disease: OR/RRs = 1.51 (95% CI: 1.20-1.90); Mild cognitive impairment: OR/RRs = 1.31 (95% CI: 0.89-1.94)). Furthermore, subgroup analysis showed significant correlations between cognitive deficits and tooth loss, periodontitis, whereas no significant correlation was found between deep periodontal pockets and cognitive deficits (tooth loss: OR/RRs = 1.57 (95% CI: 1.39- 1.77); periodontitis: OR/RRs = 1.43 (95% CI: 1.03-2.00); deep periodontal pockets: OR/RRs = 1.24 (95% CI: 0.77-2.00)). Conclusions: This review suggests a significant correlation between periodontal disease and cognitive deficits. Interventional studies for periodontal disease may be beneficial for patients with cognitive deficits

[The role of extracellular signal regulated kinase 1/2 in mediating osteodifferentiation of human periodontal ligament cells induced by cyclic stretch].

OBJECTIVE: This study aimed to investigate the mechanism of cyclic stretch that promotesthe osteogenic differentiation of human periodontal ligament cells (hPDLCs) through the mediation of extracellular-signal-regulated kinase 1/2 (ERK1/2). METHODS: hPDLCs were isolated through the explant method and cultured in vitro. hPDLCs were mechanically stimulated by a multi-channel cell-stress-loading system for 1, 3, 6, 12, and 24 h. The magnitude of stretch was 10% deformation, and the frequency was 0.5 Hz. Nonloaded cells were used as control group. ERK1/2 activation was blocked by U0126, a specific ERK1/2 pathway inhibitor. Additionally, hPDLCs were transfected with adenoviral vector encoding dominant negative ERK1/2 (DN-ERK1/2) to continuouslyinhibit ERK1/2 activation. The mRNA and protein levels of target geneswere detected through real-time polymerase chain reaction and Western blot. RESULTS: Cyclic stretching promoted the expression of ERK1/2, osteocalcin (OCN) mRNA, and bone sialoprotein (BSP) mRNA. The expression of runt-related transcription factor (Runx) 2 protein and mRNA also increased at 3 and 6 h of cyclic stretching. The inhibition of ERK1/2 by U0126 and DN-ERK1/2 suppressed the expressionof Runx2 mRNA, OCN mRNA, BSP mRNA, Runx 2 protein, and p-ERK1/2 protein relative to that in stretched cells without the ERK1/2 inhibitor. CONCLUSIONS: ERK1/2 is a critical molecule in the mediation ofthe osteogenic differentiation of hPDLCs under mechanical stimulation. ERK1/2 activation induced the elevation of Runx2 protein levels, which may be involved in the stretch-induced expressions of OCN and BSP.

The role of extracellular signal regulated kinase 1/2 in mediating osteodifferentiation of human periodontal ligament cells induced by cyclic stretch / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aimed to investigate the mechanism of cyclic stretch that promotesthe osteogenic differentiation of human periodontal ligament cells (hPDLCs) through the mediation of extracellular-signal-regulated kinase 1/2 (ERK1/2).</p><p><b>METHODS</b>hPDLCs were isolated through the explant method and cultured in vitro. hPDLCs were mechanically stimulated by a multi-channel cell-stress-loading system for 1, 3, 6, 12, and 24 h. The magnitude of stretch was 10% deformation, and the frequency was 0.5 Hz. Nonloaded cells were used as control group. ERK1/2 activation was blocked by U0126, a specific ERK1/2 pathway inhibitor. Additionally, hPDLCs were transfected with adenoviral vector encoding dominant negative ERK1/2 (DN-ERK1/2) to continuouslyinhibit ERK1/2 activation. The mRNA and protein levels of target geneswere detected through real-time polymerase chain reaction and Western blot.</p><p><b>RESULTS</b>Cyclic stretching promoted the expression of ERK1/2, osteocalcin (OCN) mRNA, and bone sialoprotein (BSP) mRNA. The expression of runt-related transcription factor (Runx) 2 protein and mRNA also increased at 3 and 6 h of cyclic stretching. The inhibition of ERK1/2 by U0126 and DN-ERK1/2 suppressed the expressionof Runx2 mRNA, OCN mRNA, BSP mRNA, Runx 2 protein, and p-ERK1/2 protein relative to that in stretched cells without the ERK1/2 inhibitor.</p><p><b>CONCLUSIONS</b>ERK1/2 is a critical molecule in the mediation ofthe osteogenic differentiation of hPDLCs under mechanical stimulation. ERK1/2 activation induced the elevation of Runx2 protein levels, which may be involved in the stretch-induced expressions of OCN and BSP.</p>

Right maxillary sinus epidermoid cyst huge: report of 1 case / 临床耳鼻咽喉头颈外科杂志

Dermoid cysts occur in the maxillary sinus mucosa were rare. Patient's CT showed: maxillary sinuses Sinus cavity expansion, sinus wall thinning. The inside of the sinus wall disappeared, the maxillary sinus filled with soft tissue mass shadow. Bacterial culture: Staphylococcus aureus. Pathological report: a very small a mount of scattered broken squamous epithelium and keratosis, no atypia cells. Lesions consistent with epidermoid cyst. Patients with epidermoid cysts, formated probably in the process of embryonic development, the reasons of rapid growth may be considered for inflammatory stimulation.

Evaluation of people's acceptable range for posed smile characteristic index / 中华医学美学美容杂志

Objective To obtain the acceptable range for posed smile characteristic index,in order to supply diagnostic and therapeutic basis for orthodontic treatment.Methods The 200 subjects included in the study consisted of 100 experienced orthodontists and 100 laypersons.Both two frontal posed smile photographs of man and woman were changed by several smile characteristic indexes,including the amount of incisor exposure,amount of gingival display,smile arc,buccal corridor fill,horizontal inclination of maxillary occlusal plate and distance from lower lip to maxillary incisor.All the subjects were desired to evaluate each images according to their own aesthetic standard.Results Each acceptable range for the amount of incisor exposure,amount of gingival display,smile arc,buccal corridor fill,horizontal inclination of maxillary occlusal plate and distance from lower lip to maxillary incisor,was 75 ％-100 ％ (male and female),0-2 mm (male) and 0-3 mm (female) ; 50 ％-100 ％(male and female) ; 0 ％-15 ％ (male) and 0 ％-20 ％ (female) ; 0-6° (male and female) ; 0 mm (male and female)(P＜0.05),respectively.And there was perception difference between the orthodontists and the laypersons on smile evaluation (P＜0.05).Conclusions Posed smile analysis should be an im portant aspect of orthodontic diagnosis and treatment planning.Orthodontists should not disturb con sonant smiles but create them with proper bracket positioning.