A regenerative approach for temporomandibular joint repair: An in vitro and ex vivo study.

BACKGROUND: Current clinical approaches to regenerate temporomandibular joint (TMJ) articulating cartilage defects only treat the symptoms (i.e. pain and dysfunction) and do not seek to restore joint integrity for long-term relief. Therefore, we investigated a novel self-assembling tissue-engineered cartilage to overcome this significant clinical issue for TMJ regenerative purposes. OBJECTIVES: Examine the maturation of dynamic self-regenerating cartilage (dSRC) using auricular chondrocytes and evaluate a novel combinatorial approach with fractional laser treatment and dSRC implantation for TMJ cartilage repair. MATERIALS AND METHODS: A suspension of 107 freshly harvested rabbit ear chondrocytes was cultured under a continuous reciprocating motion to form the dSRC. After 2, 4 and 8 weeks of culture, dSRC samples were stained with H&E, Safranin-O and Toluidine Blue. Immunohistochemistry (IHC) was performed for collagens type I and II. Channels (300-500 µm diameter and 1.2-1.5 mm depth) were created in six freshly harvested condyles using a fractional Erbium laser. Two groups were tested: dSRC in a laser-ablated lesion (experimental) and an empty laser-ablated channel (control). TMJ condyles were cultured for up to 8 weeks and analysed as described above. RESULTS: H&E staining showed a high cell density in dSRC compared to native cartilage. All dSRC groups demonstrated intense Safranin-O staining, indicating high glycosaminoglycan (GAG) production and intense Toluidine Blue staining showed high proteoglycan content. IHC confirmed that dSRC consisted predominantly of collagen type II. The experimental group showed improved cartilage repair at both time points compared to the empty channels. CONCLUSION: dSRC viability and successful matrix formation were demonstrated in vitro. The combination of fractional laser ablation and dSRC implantation enhanced cartilage repair.

Rodents as an animal model for studying tooth extraction-related medication-related osteonecrosis of the jaw: assessment of outcomes.

OBJECTIVE: To assess the outcomes of several rodent animal models for studying tooth extraction-related medication-related osteonecrosis of the jaw (MRONJ). DESIGN: After a search of the databases, 2004 articles were located, and 118 corroborated the inclusion factors (in vivo studies in rodents evaluating tooth extraction as a risk factor for the development of MRONJ). RESULTS: Numerous studies attempting to establish an optimal protocol to induce MRONJ were found. Zoledronic acid (ZA) was the most used drug, followed by alendronate (ALN). Even when ZA did not lead to the development of MRONJ, its effect compromised the homeostasis of the bone and soft tissue. The association of other risk factors (dexamethasone, diabetes, and tooth-related inflammatory dental disease) besides tooth extraction also played a role in the development of MRONJ. In addition, studies demonstrated a relationship between cumulative dose and MRONJ. CONCLUSIONS: Both ZA and ALN can lead to MRONJ in rodents when equivalent human doses (in osteoporosis or cancer treatment) are used. Local oral risk factors and tooth-related inflammatory dental disease increase the incidence of MRONJ in a tooth extraction-related rodent model.

Effects of periodontitis on cancer outcomes in the era of immunotherapy.

Periodontitis results from dysbiosis of the oral microbiome and affects up to 70% of US adults aged 65 years and older. More than 50 systemic inflammatory disorders and comorbidities are associated with periodontitis, many of which overlap with immunotherapy-associated toxicities. Despite the increasing use of immunotherapy for the treatment of cancer, uncertainty remains as to whether the microbial shift associated with periodontal disease can influence response rates and tolerance to cancer immunotherapy. We herein review the pathophysiology of periodontitis and the local and systemic inflammatory conditions related to oral dysbiosis, and discuss the overlapping adverse profiles of periodontitis and immunotherapy. The effects of the presence of Porphyromonas gingivalis, a key pathogen in periodontitis, highlight how the oral microbiome can affect the hosts' systemic immune responses, and further research into the local and systemic influence of other microorganisms causing periodontal disease is necessary. Addressing periodontitis in an ageing population of people with cancer could have potential implications for the clinical response to (and tolerability of) immunotherapy and warrants further investigation.

Photo-crosslinked GelMA loaded with dental pulp stem cells and VEGF to repair critical-sized soft tissue defects in rats.

BACKGROUND: Tissue engineering of skin and mucosa is essential for the esthetic and functional reconstruction of individuals disfigured by trauma, resection surgery, or severe burns while overcoming the limited amount of autograft and donor site morbidity. PURPOSE: We aimed to determine whether a combination of Gelatin-methacryloyl (GelMA) hydrogel scaffold alone or loaded with either dental pulp stem cells (DPSCs) and/or vascular endothelial growth factor (VEGF) could improve skin wound healing in rats. MATERIALS AND METHODS: Four 10 mm full-thickness skin defects were created on the dorsum of 15 Sprague-Dawley rats. The wounds were treated with GelMA alone, GelMA+DPSCs, or GelMA+DPSCs+VEGF. Unprotected wounds were used as controls. Animals were euthanized at 1-, 2-, and 4 weeks post-surgery, and the healing wounds were harvested for clinical, histological, and RT-PCR analysis. RESULTS: No signs of clinical inflammation were observed among all groups. Few and sparse mononuclear inflammatory cells were observed in GelMA+DPSCs and GelMA+DPSCs+VEGF groups at 2 weeks, with complete epithelialization of the wounds. At 4 weeks, the epidermis in GelMA+DPSCs and GelMA+DPSCs+VEGF groups was indistinguishable from the empty defect and GelMA groups. The decrease in cellularity and increase in density of collagen fibers were observed over time in both GelMA+DPSCs and GelMA+DPSCs+VEGF groups but were more evident in the GelMA+DPSCs+VEGF group. The GelMA+DPSCs+VEGF group showed a higher expression of the KER 10 gene at all time points compared with the other groups. Expression of Col1 A1 and TGFß-1 were not statistically different over time neither among the groups. CONCLUSION: GelMA scaffolds loaded with DPSCs, and VEGF accelerated the re-epithelialization of skin wounds.

Post-legalization Consumption of Cannabis at Massachusetts General Hospital Dental Group.

AIM: The aim of this study was to evaluate the profile of patients undergoing dental treatment in relation to cannabis use. MATERIALS AND METHODS: A comprehensive questionnaire was used to address the type of cannabis preparations, route of intake, frequency of usage, and potential reasoning for use (recreational vs medical use) of patients from the MGH Dental Group. RESULTS: Seventy-six adult patients completed the survey. Sixty-one percent of the participants were female, with the majority (59%) of the participants being ≥51 years or older. Twelve of the 76 participants (16%) were 18-30 years old. The remaining 19 patients (25%) who participated in the study were 31-50 years old. The sample included participants who were predominately non-Hispanic (63 patients, 83%) and White (59 patients, 78%). The majority of patients either had their first use of cannabis prior to 18 years of age (36%) or did not respond to this question (34%) at all. The predominant age at consistent cannabis use was 18-30 years (13%). The most common method of cannabis intake in the preceding year for participants was smoking, followed by ingesting, using cannabidiol (CBD), and vaping (least common). Recreational cannabis use was reported in 47% of the participants vs 28% of participants who reported cannabis intake for medical use. CONCLUSION: This preliminary study characterized the profile of patients undergoing dental treatment in relation to marijuana use. Diminishing restraints to cannabis use may affect the dental profession. CLINICAL SIGNIFICANCE: It is important for dentists to understand cannabis-related oral health conditions to provide customized patient treatments.

Association of hyaluronic acid with a deproteinized bovine graft improves bone repair and increases bone formation in critical-size bone defects.

BACKGROUND: This study is designed to evaluate the potential of different formulations of hyaluronic acid (HA) to improve new bone formation in critical-size calvaria defect (CSD) when combined with a deproteinized bovine graft (DBG) material. METHODS: Thirty male rats were used. A 5-mm-diameter CSD was created and three experimental groups (n = 10) were randomly assigned based on the treatments performed. Group DBG: CSD filled with a DBG; group DBG/LV: CSD filled by the combination of DBG and HA in a low-viscosity crosslinking agent; group DBG/HV: CSD filled by the combination of DBG and HA in a high-viscosity crosslinking agent. Animals were euthanized 30 days postoperatively. Histological, histometric (percentage of newly formed bone [PNFB], percentage of remaining graft particles, histochemical, and immunohistochemical (bone morphogenetic protein 2/4 [BMP2/4], osteocalcin [OCN], and tartrate-resistant acid phosphatase [TRAP]) analyses were performed. RESULTS: The highest PNFB was observed in DBG/HV when compared with the other groups (P ≤0.05). DBG/LV and DBG/HV presented almost no inflammatory cells. In contrast, inflammation was observed in group DBG. Extensive resorption of graft particles was observed in group DBG, which was not present in DBG/LV and DBG/HV as confirmed by the larger size of the particles (P ≤0.05). BMP2/4 and OCN immunolabeling were higher in DBG/HV when compared with group DBG (P ≤0.05). Increased number of TRAP-positive cells was observed in DBG/LV and DBG/HV (P ≤0.05). Lower percentage of mature collagen fibers was observed in DBG/HV (P ≤0.05). CONCLUSION: The combination of HA in a high-viscosity crosslinking agent with DBG improves the bone repair process and increases the amount of newly formed bone towards CSDs in rat calvaria.

Periodontal disease severity in subjects with dementia: A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE: Despite clinical trials and reviews attempt to assess a possible relationship between dementia and periodontal disease, no meta-analysis has been performed and this issue remains undetermined. The aim of this study is to conduct a systematic review and meta-analysis to assess severity of periodontitis in subjects with dementia. METHODS: The search was conducted in Pubmed, Embase/MEDLINE. Two independent reviewers extracted data and assessed the risk bias (Newcastle-Ottawa scale). Meta-analyses were performed using the means of probing depth (PD) and clinical attachment loss (CAL) in patients with or without dementia. The mean difference were analyzed (P ≤ 0.05). RESULTS: Fourteen studies were included in the systematic review. In the qualitative analysis, most studies reported higher prevalence of periodontal disease in dementia patients. The studies had low risk of bias and two meta-analyses were performed for each parameter, including or not a cross-sectional study. The meta-analyses including the cross-sectional study demonstrated significant association between dementia and periodontal disease (mean difference: PD = 1.41; CAL = 1.40, P < 0.05), however, it wasn't confirmed when the cross-sectional study was removed (1.25 mm, P < 0.22) and CAL (1.20 mm, P < 0.22). CONCLUSION: Although the qualitative analysis have suggested worse periodontal conditions in dementia patients, due to different study types and the high heterogeneity among them, the meta-analysis does not support the association between dementia and severity of periodontal disease.

Descrição anatômica do plexo braquial de Callithrix jacchus e Callithrix penicillata / Anatomic description of brachial plexus of Callithrix jacchus and Callithrix penicillata

Callithrix jacchus e Callithrix penicillata são primatas de pequeno porte cuja utilização como modelo anatômico tem se mostrado cada vez mais frequente, não somente pela praticidade no manuseio como facilidade no trato em criatório e sua taxa de reprodução. Este estudo teve como objetivo descrever os componentes dos plexos braquial em Callithrix jacchus e penicillata. Para tanto, três espécimes com aproximadamente 8 anos e 240 g foram fixados em solução de formaldeído a 10%, e posteriormente dissecados e fotodocumentados. O plexo braquial do Callithrix jacchus e penicillata originou-se dos nervos espinhais C5 a T1 constituindo os troncos cranial, médio e caudal. A composição do plexo braquial destes animais se assemelha ao de outros primatas, bem como a outros mamíferos.(AU)

Callithrix jacchus and Callithrix penicillata are small primates used as anatomic model, not only for convenience in handling as ease in regard to breeding and reproductive rate. The aim of this study was to describe the components of the brachial plexus in Callithrix jacchus and C. penicillata. Three specimens about 8 years old and weighing 240g were fixed in 10% formaldehyde and subsequently dissected and photodocumented. The brachial plexus of Callithrix jacchus and C. penicillata originates from the spinal nerves C5 to T1 in continuation of the cranial, medium and flow trunk. The composition of the brachial plexus of these animals is similar to the one of other primates ands other mammals.(AU)