shahroo etemad-moghadam

Various decision-making dilemmas arise for clinician in their practice, and one such dilemma involves dealing with medical or dental errors. Despite efforts to minimize errors and prevent harm to patients, complications arising from diagnostic or therapeutic mistakes can sometimes be irreversible. In such situations, it is crucial for dentists to engage in ethical encounters with their patients and investigate the root cause of the error. In this study, an approach was suggested for the management of detection of diagnostic error in pathology using the World Dental Federation ethical decision-making model.

Different medicinal properties of thyme plant, anticancer effects of green synthesis of gold nanoparticles and low survival of patients with pharyngeal cancer are the main reasons for this research on the pharyngeal cancer FaDu cell line.

Following preparation of thyme extract, green synthesis was performed on AuCl3 gold salt to obtain nanomedicine. Infrared and X-ray diffraction spectroscopic tests along with scanning and transmission electron microscopy was carried out for optimization of the synthesized nanomedicine. The viability of FaDu cells was assessed by MTT after 24-, 48-, and 72-hours treatment with different concentrations of the nanomedicine and LC50 was determined. Cell apoptosis was measured by flow cytometry.  

The mean survival of FaDu cells after treatment with different concentrations of gold nanomedicine at each of the three time points was significantly lower compared to untreated cells (P<0.001). The LC50 value of the nanomedicine following 48 hours of exposure was approximately 40 μg/ml. The rate of early and late apoptosis in the treated cells was calculated as 37.5%.

The results of the present study confirmed that gold nanoparticles synthesized from thyme extract have cytotoxic and apoptosis induction effects on FaDu pharyngeal cancer cells. Therefore, further study on the use of this nanomedicine in the treatment of pharyngeal malignancy is recommended

Due to the increasing prevalence and high mortality rate of oral squamous cell carcinoma (OSCC) and problems with its routine treatments, more recent modalities like photodynamic therapy (PDT) have been developed. PDT effectively destroys tumor cells with minimum side effects. Research on in vitro effects of PDT may be helpful in determining the molecular mechanisms responsible for its effectiveness and can lead to the development of more efficient techniques. The aim of this study was to review the use of PDT in OSCC among in vitro studies.

A literature search for English articles on PDT in OSCC was performed in PubMed, Scopus, Google Scholar, and Web of Science. Data were extracted based on the inclusion/exclusion criteria, which were detailed using the PICO framework: all eligible in vitro studies evaluating the effects of PDT on the viability of OSCC compared to controls without PDT were included.

Forty-one out of 567 studies were selected. The tongue was the most common OSCC site, 5-aminolevulinic acid was the most used photosensitizer (PS), cell viability/toxicity and apoptosis were the most evaluated outcomes, and lasers with wavelengths of 600-700 nm were the most common light sources and wavelengths respectively.

PDT showed promising effects on reducing the viability of OSCC cells. Cell lines from various sources or even those originating from the same location sometimes responded differently to the same protocol. Considering the favorable results obtained from natural PSs and regarding their additional health-promoting properties, their use in future investigations with different cell lines and light specifications is recommended.

Considering the relatively high prevalence of oral mucosal ulcers, their fast healing is of significance.

This study aimed to histopathologically compare the effects of 810 nm and 940 nm diode laser on the healing of iatrogenic oral ulcers in rabbits.

In this single-blind experimental study, mucosal ulcers measuring 3mm in diameter and 1mm in depth were bilaterally created in the buccal mucosa of 18 rabbits using a biopsy punch. The defects were irradiated with 810 nm diode laser on the right side and 940 nm diode laser on the left side. Biopsy samples of the same depth were obtained from the ulcers on days 3 and 7 followed by histopathological analysis. The intensity of inflammation was determined on hematoxylin-eosin-stained sections using a four-point scale. Data were analyzed employing the Wilcoxon signed rank test.

Thedegree of inflammation was not significantly different between the 810nm and 940nm diode laser groups on day 3; but on day 7, animals receiving 810 nm experienced a significantly lower degree of inflammation compared to those treated with 940 nm laser (p= 0.028).

When comparing 810- and 940-nm diode lasers, 810 nm irradiation significantly decreased the severity of inflammation in oral wounds created on the buccal mucosa of rabbits in a time-dependent manner.

The aim of this study was to compare conventional and microwave‑assisted decalcification of sheep bone with and without teeth and to detect any difference in tissue detail preservation, staining quality, and rate of decalcification.

In this method analysis study, twenty‑four specimens consisting of 12 blocks of mandibular molars with their surrounding bone and 12 blocks of mandibular osseous tissue were allocated into two microwave or routine decalcification groups using 5% nitric or formic acid as decalcifying agents. In addition to decalcification rate, a number of variables were used to assess staining quality and tissue detail preservation which were compared between the two groups using Mann–Whitney test (P < 0.05).

Time to complete decalcification was significantly reduced in the microwave‑treated samples as compared to the conventional method, regardless of the decalcifying agent (P = 0.025). For both acids, most variables related to staining quality and tissue detail preservation were similar between the techniques (P > 0.05). Patchy staining in bone samples and tissue tears in bone + teeth specimens were more common in the routine method when using nitric acid (NAc) (P = 0.046) and formic acid (FAc) (P = 0.046), respectively. In comparing acids, the performance of FAc was slightly inferior to that of NAc, especially for specimens containing both tooth and bone.

The use of microwave technology can accelerate decalcification of bone and teeth of sheep mandibles and at the same time preserve tissue structure and staining quality. Further studies are required to help select the best demineralizing agent, especially in specimens containing bone and teeth.

Despite the similarities between OSCC and ESCC, it should be noted that ESCCs have a relatively low survival rate compared with OSCCs. The tumor-associated stroma is an essential component for the preservation, development, and metastasis of the cancers, such as SCC. To our knowledge, mast cells and angiogenesis were evaluated in either ESCC or OSCC. Moreover, there are controversy about the correlation between mast cells and angiogenesis in these tumors. Therefore, the aim of this study was to evaluate and compare the density of mast cells and microvessel density (MVD) in ESCC and OSCC.

This study was scheduled using 46 paraffin blocked samples including 23 OSCCs and 23ESCCs. Immunohistochemical staining was conducted using CD31 monoclonal antibody and methylene blue staining was done for mast cells. Statistical analysis was performed by SPSS 20 using T test, One-way ANOVA and Pearson correlation analysis.

MVD was significantly higher in OSCCs as compared to ESCCs (P=0.02) with a mean of 76.26 and 62.04, respectively. Conversely, ESCCs (16.47) showed significantly higher (P=0.04) mast cell density than that of OSCCS (11.30). Pearson correlation analysis showed no association between MVD and mast cell density in either OSCC or ESCC (P=0.51 & P=0.34 respectively).

A significant difference between the mean mast cell count and MVD in OSCC &ESCC might be to some extent responsible for the different biological behaviors of these cancers. Further studies should be performed to explore the precise role of mast cells and angiogenesis and the possible effect on the different survival of OSCC &ESCC.

Induction of premalignant lesions in animal models is of high value for research purposes. This study aimed to induce dysplasia in hamster mucosal pouch for investigation of dysplastic lesions usingdimethylbenz(a)anthracene. The buccal pouch of 10 hamsters was painted with dimethylbenz(a)anthracene for 10 weeks every other day. At 5 and 10 weeks, they underwent histopathological analysis. Clinically, there was no change until week 7; after which mucosal thickening occurred. Hamsters scarified at 5 weeks and 10 weeks demonstrated mild and moderate dysplasia, respectively. dimethylbenz(a)anthracene is a useful tool for inducing dysplastic lesions in the buccal pouch mucosa of hamsters.

Chronic liver disease (CLD) affects millions of people and its impact on bone loss has become a subject of interest. Nitric oxide and endogenous opioids are suggested to increase during cholestasis/cirrhosis and may impact bone resorption by different mechanisms. The receptor activator of nuclear factor-κB (RANK)/RANK-ligand (RANKL)/osteoprotegerin (OPG) signaling pathway regulates bone resorption, but its role in metabolic bone disease subsequent to CLD is unknown. We aimed to investigate the involvement of nitrergic and opioidergic systems in bone loss relative to the RANK/RANKL/OPG pathway, in bile duct-ligated (BDL) rats. Eighty BDL/sham-operated (SO) rats received injections of 3 mg/kg/day Nω-Nitro-L-arginine methyl ester ± naltrexone (10 mg/kg/day) or saline for 28 days. Plasma bone turnover markers, OPG, RANK, and RANKL along with mRNA expression levels of the latter three were assessed. Plasma bone turnover markers and OPG level increased, but RANKL decreased in the BDL group compared with their SO controls (both: P ≤ 0.05). Administration of naltrexone reduced bone turnover markers and OPG level while increased RANKL content in comparison to BDL rats (P ≤ 0.05). As compared to untreated BDL rats, nitric oxide inhibition showed no effect on bone turnover marker i.e. OPG, RANK, and RANKL levels. BDL significantly increased RANK mRNA, but had no significant effect on RANKL and OPG mRNA expression. The lack of association between plasma levels and quantitative gene expression of RANKL and OPG suggests an indirect function of these markers in BDL rats. Considering that opioid receptor blockage by naltrexone in BDL animals caused a significant decrease in OPG and an increase in RANKL plasma contents, it could be postulated that the opioidergic system may have a regulatory effect on these bone markers.

Captopril is an oral angiotensin-converting-enzyme (ACE) inhibitor extensively used in the treatment of hypertension and heart failure. ACE has been suggested to function in bone cells and might therefore impact orthodontic tooth movement (OTM). Considering the controversy surrounding the effects of ACE and its inhibitors on osseous tissues, we aimed to evaluate the effect of captopril on OTM for the first time in a rat model.
Orthodontic appliances were fixed between the left first molars and incisors of 30 rats divided into three groups (n=10) receiving captopril, saline or no treatment. Following sacrifice on day 21, the amount of tooth movement was measured as the distance created between the first and second molars. Bone density was assessed by lateral cephalograms on days 1 and 21 and osteoclast number, root resorption and periodontal ligament (PDL) width were analyzed histologically. One-way ANOVA followed by post-hoc test were used for statistical analysis (P OTM significantly increased in the captopril group compared to the saline and no-treatment groups (P The present study showed that captopril administration could lead to increased OTM and decreased bone density in rats. Further studies are suggested to clarify its exact role at the cellular and molecular levels.

Keratocystic odontogenic tumor (KCOT) is a locally aggressive lesion with a known potential for repeated recurrences. The distinct clinical features and explicit cystic histologic characteristics concurrent with the neoplastic nature of this lesion have led to several studies and comparisons with other odontogenic cysts and tumors. Fascin is an actin-bundling protein which has not been evaluated in odontogenic lesions. The aim of this study was to assess the expression of fascin in KCOT and dentigerous cyst (DC). In this cross-sectional investigation, the paraffin blocks of 18 KCOTs and 9 DCs were selected and subjected to immunohistochemistry using monoclonal antibody against fascin. Staining was scored by estimating the percentage of immunoreactive epithelial cells. Mann-Whitney-U test was applied for statistical analysis (P<0.05). Fascin expression was observed throughout the entire epithelial lining of the DCs, while in 50% of the KCOTs, immunostaining was negative in the basal layer and parakeratinized cells adjacent to the lumen. A statistically significant difference in the expression pattern of fascin was found between the studied KCOTs and DCs (P=0.01). Considering the variation in fascin expression patterns between the sample of KCOTs and DCs in the present investigation, it can be suggested that this protein might have a role in the biologic behavior and pathogenesis of KCOT and DC.