Thiago de Santana Santos

Role of inflammation in oral carcinogenesis (Part II): CD8, FOXP3, TNF-α, TGF-β and NF-κB expression

Due to the frequent presence of inflammation in cases of carcinoma and its use as a parameter for the assessment of tumor aggressiveness, the role of inflammation in oral carcinogenesis was investigated. This was performed by evaluating the expression of cellular markers, cytokines and nuclear transcription factors that identify the cells that participate in the antitumor defense in cases of oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). A semi-quantitative immunohistochemical analysis was performed for the transcription factors cluster of differentiation 8 (CD8), forkhead box P3 (FOXP3), transforming growth factor (TGF)-β, tumor necrosis factor (TNF)-α and nuclear factor κ-light chain enhancer of activated B-cells (NF-κB), in cases of OED and OSCC. CD8, TGF-β, TNF-α and NF-κB participated in the processes of tumor transformation and progression. The presence of inflammatory infiltrate in cases of OED favors the transformation and invasion process when stromal TNF-α and NF-kB are overexpressed, as NF-kB activated by TNF-α during inflammation predisposes the lesion to transformation, functioning as a link between inflammation and cancer. The control of these inflammatory mediators may prevent malignant transformation in the oral cavity.

Oral and maxillofacial myiasis: a case series and literature review

OBJECTIVE The aim of this study was to describe a series of 10 cases of oral-maxillofacial myiasis, discussing its main features, demographic distribution, and treatment aspects. STUDY DESIGN A retrospective study was carried out involving male and female patients of any age with oral-maxillofacial myiasis. The sample was determined by spontaneous demand at the emergency ward of a hospital between January 2005 and January 2011 (6 years). After treatment of each case, data were gathered on the presence of associated systemic disorders, time elapsed since onset of the disease, and treatment established. A review of the literature on this topic was also carried out. RESULTS The sample was made up of 10 patients, all treated with surgical debridement whether or not associated with the use of oral ivermectin. Mean time elapsed since the onset of the disease ranged from 4 to 36 months. The middle third of the face was the most frequently affected region (7 cases). Oral-maxillofacial myiasis predominantly affected the male gender (70%). CONCLUSIONS Oral-maxillofacial myiasis affects individuals with poor hygiene and neurologic and/or psychologic alterations. It occurs predominantly in countries near the tropics. The treatment of choice is surgical debridement.

Comparative analysis of preemptive analgesic effect of tramadol chlorhydrate and nimesulide following third molar surgery

The aim of this prospective, randomized, controlled, paired trial was to perform a comparative analysis of the preemptive analgesic effect of nimesulide and tramadol chlorhydrate during third molar surgery. The study was carried out between March and November 2009, involving 94 operations in 47 male and female patients with bilateral impacted lower third molars in comparable positions. The sample was divided into two groups. Group A received an oral dose of 100 mg of nimesulide 1 h prior to surgery. Group B received an oral dose of 100 mg of tramadol chlorhydrate 1 h prior to surgery. The following aspects were evaluated in the postoperative period: adverse effects of the drugs; amount of rescue medication used (acetaminophen 750 mg); and pain 5, 6, 24, 36, 48, 60, 72 and 84 h after surgery using a visual analog pain scale. Peak pain occurred 5 h after surgery in both groups, with a mean pain score of 2.3 in Group A and 3.0 in Group B; this difference did not achieve statistical significance (p > 0.141). Based on the sample studied, nimesulide and tramadol chlorhydrate demonstrate similar preemptive analgesic effects when used in lower third molar surgeries.

Poly(vinylidene-trifluoroethylene)/barium titanate composite for in vivo support of bone formation

In this study, we evaluated the effect of poly(vinylidene fluoride-trifluoroethylene)/barium titanate (P(VDF-TrFE)/BT) membrane on in vivo bone formation. Rat calvarial bone defects were implanted with P(VDF-TrFE)/BT and polytetrafluoroethylene (PTFE) membranes, and at 4 and 8 weeks, histomorphometric and gene expression analyses were performed. A higher amount of bone formation was noticed on P(VDF-TrFE)/BT compared with PTFE. The gene expression of RUNX2, bone sialoprotein, osteocalcin, receptor activator of nuclear factor-kappa B ligand, and osteoprotegerin indicates that P(VDF-TrFE)/BT favored the osteoblast differentiation compared with PTFE. These results evidenced the benefits of using P(VDF-TrFE)/BT to promote new bone formation, which may represent a promising alternative to be employed in guided bone regeneration.

Clinical study of hemodynamic changes comparing 4% articaine hydrochloride with 1:100,000 and 1:200,000 epinephrine

OBJECTIVE To evaluate hemodynamic changes with the use of 4% articaine and 2 different concentrations of epinephrine (1:100,000 and 1:200,000) in the surgical removal of symmetrically positioned lower third molars. STUDY DESIGN A prospective, randomized, double-blind clinical trial was carried out involving 42 patients each undergoing 2 surgeries on separate occasions under local anesthesia with 4% articaine and either epinephrine 1:100,000 or 1:200,000. The following parameters were assessed at 4 different moments: systolic, diastolic, and mean blood pressure; heart rate; oxygen saturation; rate pressure product (RPP); and pressure rate quotient (PRQ). RESULTS The concentration of epinephrine did not affect diastolic blood pressure or oxygen saturation during the surgeries. Significant differences between were detected for heart rate, RPP, and PRQ (P < .05). CONCLUSIONS The epinephrine concentration (1:100,000 or 1:200,000) in a 4% articaine solution influences hemodynamic parameters without perceptible clinical changes in healthy patients undergoing lower third molar removal.

Participation of TNF-α in Inhibitory Effects of Adipocytes on Osteoblast Differentiation.

Mesenchymal stem cells from bone marrow (BM‐MSCs) and adipose tissue (AT‐MSCs) are attractive tools for cell‐based therapies to repair bone tissue. In this study, we investigated the osteogenic and adipogenic potential of BM‐MSCs and AT‐MSCs as well as the effect of crosstalk between osteoblasts and adipocytes on cell phenotype expression. Rat BM‐MSCs and AT‐MSCs were cultured either in growth, osteogenic, or adipogenic medium to evaluate osteoblast and adipocyte differentiation. Additionally, osteoblasts and adipocytes were indirectly co‐cultured to investigate the effect of adipocytes on osteoblast differentiation and vice versa. BM‐MSCs and AT‐MSCs exhibit osteogenic and adipogenic potential under non‐differentiation‐inducing conditions. When exposed to osteogenic medium, BM‐MSCs exhibited higher expression of bone markers compared with AT‐MSCs. Conversely, under adipogenic conditions, AT‐MSCs displayed higher expression of adipose tissue markers compared with BM‐MSCs. The presence of adipocytes as indirect co‐culture repressed the expression of the osteoblast phenotype, whereas osteoblasts did not exert remarkable effect on adipocytes. The inhibitory effect of adipocytes on osteoblasts was due to the release of tumor necrosis factor alpha (TNF‐α) in culture medium by adipocytes. Indeed, the addition of exogenous TNF‐α in culture medium repressed the differentiation of BM‐MSCs into osteoblasts mimicking the indirect co‐culture effect. In conclusion, our study showed that BM‐MSCs are more osteogenic while AT‐MSCs are more adipogenic. Additionally, we demonstrated the key role of TNF‐α secreted by adipocytes on the inhibition of osteoblast differentiation. Thus, we postulate that the higher osteogenic potential of BM‐MSCs makes them the first choice for inducing bone repair in cell‐based therapies. J. Cell. Physiol. 230: 204–214, 2016.

Effect of collagen sponge and fibrin glue on bone repair

ABSTRACT The ability of hemostatic agents to promote bone repair has been investigated using in vitro and in vivo models but, up to now, the results are inconclusive. Objective In this context, the aim of this study was to compare the potential of bone repair of collagen sponge with fibrin glue in a rat calvarial defect model. Material and Methods Defects of 5 mm in diameter were created in rat calvariae and treated with either collagen sponge or fibrin glue; untreated defects were used as control. At 4 and 8 weeks, histological analysis and micro-CT-based histomorphometry were carried out and data were compared by two-way ANOVA followed by Student-Newman-Keuls test when appropriated (p≤0.05). Results Three-dimensional reconstructions showed increased bone formation in defects treated with either collagen sponge or fibrin glue compared with untreated defects, which was confirmed by the histological analysis. Morphometric parameters indicated the progression of bone formation from 4 to 8 weeks. Additionally, fibrin glue displayed slightly higher bone formation rate when compared with collagen sponge. Conclusion Our results have shown the benefits of using collagen sponge and fibrin glue to promote new bone formation in rat calvarial bone defects, the latter being discreetly more advantageous.

Methylene Blue-Mediated Photodynamic Inactivation Followed by Low-Laser Therapy versus Miconazole Gel in the Treatment of Denture Stomatitis

PURPOSE Photodynamic therapy (PDT) appears to be an effective method for the in vitro and in vivo inactivation of Candida spp., but no clinical trials in this context have yet been conducted. The aim of this study was to compare the effect of oral miconazole gel to PDT combined with low-power laser (LPL) therapy in the treatment of denture stomatitis. MATERIALS AND METHODS Forty participants with clinical and microbiological diagnoses of type II denture stomatitis were randomly allocated to two treatment groups (PDT and miconazole gel), each with 20 individuals. The PDT group was submitted to one session of methylene blue-mediated PDT plus two sessions of low-laser therapy twice a week for 15 days. The miconazole group was submitted to the drug four times a day for 15 days. RESULTS Forty percent of the patients achieved clinical and microbiological resolution of denture stomatitis after methylene blue-mediated photodynamic inactivation followed by low-laser therapy. The cure rate associated with miconazole was 80% (p < 0.05). Fifteen days after the end of treatment, the recurrence rate was 25% in patients treated with PDT combined with LPL therapy and 12.5% in patients treated with miconazole. CONCLUSION Miconazole gel provides better results than a protocol combining methylene blue-mediated PDT and LPL therapy in the treatment of type II denture stomatitis.

Inverted papilloma (Schneiderian papilloma) with involvement of the oral cavity: report of an unusual case

Inverted Schneiderian papilloma (ISP) is a neoplasm of epithelial lining origin which arises in the respiratory mucosa that lines the nasal cavity and paranasal sinuses. The inverted Schneiderian papilloma frequently appears as a unilateral lesion in the nasal septum and extends secondarily to the nasal and paranasal sinuses. This paper reports an unusual case of this pathology with involvement of the oral cavity in a 61-year-old white man. Clinical evaluation revealed a vegetating mass in the alveolar ridge of the right maxilla that had been present for approximately 4 months. After radiographic evaluation, involvement of the maxillary sinus was detected. Microscopic evaluation, in situ hybridization and immunohistochemical analysis of the specimen led to a diagnosis of ISP moderate dysplasia associated with HPV infection.

Fresh-frozen allografts combined with bovine bone mineral enhance bone formation in sinus augmentation:

We evaluated histologically, histomorphometrically, and tomographically the effects of the association of fresh-frozen bone allograft (FFB) with bovine bone mineral (BBM) in maxillary sinus floor augmentation. In total, 34 maxillary sinuses from 29 patients, with a mean age of 51.32 (±6.44) years, underwent sinus augmentation. Patients were divided into control and test groups (17 sinuses each). The controls were grafted with allograft bone, and the test group received a combination of FFB and BBM at a 2:1 ratio. After 6 months, bone samples were collected for histological and histomorphometric examinations. The implant survival rates were 93.02% (control group) and 100% (test group) at 6 months after functional loading. Median volumetric reductions of 28.32% (17.05–44.05) and 12.62% (5.65–16.87) were observed for the control and test groups, respectively. Statistically significant histomorphometric differences were found between the control and test groups regarding newly formed bone 12.54% (10.50–13.33) vs. 24.42% (17.62–35.92), p < 0.001, total bone 48.34% (39.03–54.42) vs. 61.32% (50.61–64.96), p = 0.007, and connective tissue 51.66% (45.57–60.97) vs. 39.30% (35.03–49.37), p = 0.007. The addition of BBM to allograft bone in maxillary sinus augmentation resulted in higher percentages of new bone formation and total bone, and permitted implant placement with a low rate of osseointegration failure at the 6-month follow-up.