mojgan alaeddini

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.

Dental clinics are one of the major producers of mercury-containing waste due to the use of dental amalgam.  The atmospheric transport and persistence of mercury and its compounds in the environment, coupled with their high potential for bioaccumulation and detrimental effects on human health and ecosystems, underscore the necessity for effective management of mercury waste. Due to the lack of comprehensive and integrated guidelines for the effective management of dental amalgam waste in Iran, the objective of this study was to adapt a guideline for the management of amalgam waste in dental settings within the country.

The method used was based on the adaptation principles presented by the Ministry of Health and Medical Education, and included searching and reviewing guidelines related to the management of amalgam waste in developed countries, extracting recommendations, revising the recommendations considering the local infra-structures and conditions, and receiving expert opinions and reaching consensus according to the RAND/UCLA Appropriateness Method.

The final guideline includes 34 recommendations in 5 areas: manage-ment of the amalgam scraps, considerations for dental equipment, management of the extracted teeth containing amalgam restorations, management of the amalgam capsules, and considerations for placement and replacement of the amalgam restorations.

The use of this guideline in medical universities, public and private dental clinics, along with the supervisory role of the Ministry of Health and Medical Education, can be a way to minimize the environmental hazards of mercury.

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

Around 5% of tumors develop in the head and neck area, with nearly 50% of those appearing in the oral cavity. Oral cancer ranks as the sixth leading cause of cancer-related deaths. These figures illustrate the severity of the disease and emphasize the importance of raising awareness and providing early screening to detect and manage it. The treatment and prognosis of oral squamous cell carcinoma (OSCC) remain a significant challenge. This highlights the need for more effective treatments and strategies to improve the prognosis for individuals diagnosed with OSCC. In recent years, there has been significant progress in using microRNAs (miRNAs) as diagnostic and prognostic markers for cancer, making them a highly useful and valuable tool.

For this research, we cultured and maintained cell lines for hypopharyngeal cancer (FaDu), oral cancer (Cal 27), and PDL cells. We then used quantitative real-time polymerase chain reaction (qRT-PCR) to confirm the expression levels of the potential biomarker, has-miR-556-5p

During the discovery phase, we identified hsa-miR-556-5p as being differentially expressed, with a statistically significant increase in its expression level. More recently, we used real-time PCR to confirm that hsa-miR-556-5p is markedly up-regulated in oral squamous cell carcinoma (OSCC). Our study suggests that hsa-miR-556-5p has the potential to be a new and innovative biomarker for OSCC.

The candidate miRNA can be chosen as a promising biomarker for predicting patient outcomes and even for early detection of the disease in clinical settings.

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.

Orthodontic tooth movement (OTM) occurs in the alveolar bone; therefore, any condition affecting bone quality can alter OTM. This study aimed to evaluate the effect of amitriptyline on OTM in rats.

Forty-five male Wistar rats were randomly divided into three groups: (I) no injection, (II) injection with saline solution, and (III) injection of amitriptyline. Next, a 60-gr force was applied to the maxillary left first molar tooth of all the rats, using a nickel‒titanium closed-coil spring ligated between the maxillary incisors and the left first molar tooth. The rats were sacrificed after 21 days to measure OTM and perform histological analysis to determine the number, width, and depth of resorptive lacunae, osteoclast counts, and periodontal ligament (PDL) width.

The highest and the lowest OTM rates were found in the control and amitriptyline groups, respectively; however, there was no significant difference between the study groups in this regard. Histological analysis showed a significantly lower number of resorption lacunae in the amitriptyline group than the saline group.

Although no significant difference was noted in OTM after amitriptyline administration, a reduction in the number of resorptive lacunae in rats injected with amitriptyline suggests that amitriptyline affects the bone tissue at the cellular level.

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.

Fluoxetine is a selective serotonin re-uptake inhibitor (SSRI) widely used for depression, bipolar disorder, anxiety and obsessive-compulsive disorder. The aim of this study was to assess the effect of fluoxetine on orthodontic tooth movement (OTM) in rats.
Forty-five male Wistar rats were randomly divided into three groups namely the control group (no medication), saline and fluoxetine dissolved in saline. In all groups, nickel titanium closed-coil spring was used between the left maxillary central incisor and first molar to exert 60g force at 2mm activation. Radiographs were taken at one and 21 days. After 21 days, the rats were sacrificed. The distance between the first and second molar teeth, optical density of bone, periodontal ligament (PDL) width, lacuna length and depth and number of osteoclasts were measured and compared among the groups.
Tooth movement significantly increased in the fluoxetine group (P=0.005). No significant differences were found in osteoclast count (P=0.069). The PDL width in the mesioapical region of root was significantly different among the groups (P=0.015). Statistical analysis did not show significant differences in depth or length of lacunae in any examined part of the root (P>0.05). Bone densitometry results showed that in fluoxetine group, density of bone in all four areas (alveolar bone, hard palate, skull and mandibular bone) significantly decreased from day one to day 21 (P This study indicated that fluoxetine decreased bone density, which resulted in subsequently greater tooth movement in rats; however, further studies are needed on humans.

The aim of this study was to histologically compare the regenerative properties of two allografts manufactured by two Iranian companies.
In this study, four 8-mm defects were produced in the calvaria of 12 rabbits. In three defects, three types of allografts namely ITB, CenoBone and Grafton were placed and one defect served as control. Samples were prepared and histomorphometric evaluations were carried out after healing periods of four weeks (interval 1) and eight weeks (interval 2). Qualitative and quantities variables were compared and analyzed with SPSS software.
Mild inflammation was observed in 45% and 12.5% of the samples in the first and second intervals, respectively. Foreign body reaction was observed in only 5% of the samples. The quality of regenerated bone was immature, mixed and lamellar in 54.5%, 15.9% and 4.5% of the samples, respectively. The rate of allograft resorption was the highest and lowest in the CenoBone and Grafton samples, respectively. The mean amount of regenerated bone was higher in areas containing Grafton; however, the differences were not statistically significant.
Despite the differences in the numerical values of bone regeneration, there were no statistically significant differences in bone generation among the material groups, and allografts manufactured in Iran can be suitable alternatives to Grafton with the same good properties. Further studies are necessary to clarify the efficacy of these allografts.

Alterations in p53 and p27KIP1 have been documented as important events in the carcinogenesis of various cancers, but their prognostic role in oral squamous cell carcinoma (OSCC) remains controversial.. The present investigation aimed to evaluate the clinicopathologic and prognostic significance of p53 and p27KIP1 expression in a group of Iranian patients with OSCC..Patients and In this analytical cross-sectional study, medical records of patients with primary OSCC, diagnosed from 1994 to 2004 were reviewed and 28 subjects were selected based on the inclusion/exclusion criteria. Immunohistochemical staining using monoclonal antibodies against p53 and p27KIP1 was performed on representative archival paraffin blocks. Demographic data along with information on p53 and p27KIP1 expression, recurrence, and tumor grade was statistically analyzed using the Fischer exact test. Prognostic factors for overall survival were determined by Cox regression analysis (P < 0.05).. p53 and p27KIP1 expression were found in 28.57% (8 positive versus 20 negative) and 67.85% (19 positive versus 9 negative) of OSCC cases, respectively. There was no significant association between these two proteins (P = 0.371), and neither of them showed a significant relationship with the studied clinicopathologic variables (P > 0.05). In survival analysis, only histopathologic differentiation (17 low and moderate, 11 poor) demonstrated a significant correlation with overall survival (P = 0.048).. Despite the fact that abnormalities in p53 and p27KIP1 may be involved in the development of OSCC, their clinical significance in the studied population seems limited. Further investigation on the combined p53/p27KIP1 expression may be helpful in predicting the biologic behavior of this tumor.

Morality and ethics constitute fundamental principles of professional, educational and investigational aspects of medicine and all its branches, including dentistry. There are specific considerations in dental research which could significantly affect the design and progress of scientific projects performed in this field. The aim of the current study was to present an overview of ethical concepts governing dental research and to provide examples of common issues raised during dentistry-related investigations. Establishment of human tooth banks in major research and training centers is suggested to enhance the process of conducting more substantial research in dentistry.

Pantoprazole, is a proton pump inhibitor (PPI) prescribed for the treatment of upper gastrointestinal disorders, which in high doses has been suggested to decrease calcium absorption leading to hypocalcaemia and therefore osteoporosis. The aim of this study was to assess whether pantoprazol, could alter the rate of orthodontic tooth movement (OTM) in rats. A time course study was established using 72 rats which were divided into six groups of 12 samples each (four: vehicle; eight: pantoprazole + vehicle). Pantoprazole at a dose of 200 mg/kg suspended in carboxymethyl cellulose (0.25 percent) was administered by a gastric tube. The upper incisors and first molars were ligated by a 5 mm nickel-titanium closed-coil spring to deliver an initial force of 60 g. Animals were euthanized two weeks after orthodontic treatment followed by assessment of tooth movement and histomorphometric evaluation of the detached maxillae. Lateral skull radiographs were obtained once a week, starting from the first day to the 6th week of the study. OTM and bone density data were analyzed using independent sample t-test and repeated measures ANOVA. No significant changes in OTM measurements and optical density were observed in vehicle-receiving animals during the study (P=0.994). OTM was significantly increased after six weeks pantoprazole therapy which continued until the 7th week of the experiment (P=0.007). Optical density significantly increased in the pantoprazole-treated rats after six weeks. Long term PPI therapy at high doses could lead to osteoporosis and enhanced OTM.

Gingivitis is an inflammatory disease that affects tooth-supporting tissues and is caused by a microbe-immune response. The aim of this study was to evaluate the effects of omega-3 fatty acids on immune system regulation and the prevention and treatment of gingivitis using an animal model. Gingival inflammation was induced by lipopolysaccharide (LPS) injection. Forty adult male rats were divided into four equal groups: 1. Negative control group (sterile saline was injected into gingival tissue followed by oral gavage with saline); 2. Positive control group (LPS injection was followed by oral gavage with saline); 3. Treatment group (LPS injection was followed by oral gavage with omega-3); 4. Prophylactic group (oral gavage with omega-3 was followed by LPS injection). After 24 days, the rats were sacrificed and histological tissue samples were randomly evaluated for the inflammatory tissue changes. Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels were measured by ELISA. The levels of IL-1β and TNF-α in the prophylactic group and the level of TNF-α in the treatment group were significantly lower than those in the positive control group (P<0.05). The severity of inflammation was normal, slight, moderate, and severe in the negative control group, prophylactic group, treatment group, and positive control group, respectively. ANOVA was used for the statistical analyses, with P<0.05 regarded as significant. Prior consumption of omega-3 fatty acids is effective in reducing inflammation in induced rat gingivitis, resulting in a decreased level of biomarkers and fewer destructive effects.

Mast cells are important stromal elements, with different roles in tumorigenesis, including their effect on tumor growth, progression, differentiation and invasion. Histologic grading shows tumor differentiation and is used to predict the invasive behavior of various tumors, including oral squamous cell carcinoma (OSCC). The aim of the present study was to evaluate and mast cell density (MCD) and its relationship with different grades of OSCC based on three different valid grading systems. In this experimental study, 42 histologic block samples of OSCC were retrieved from the archives of Cancer Institute, Tehran University of Medical Sciences, based on inclusion and exclusion criteria. After hematoxylin and eosin staining of the sections, they were graded according to the methods described by Broder, Anneroth and Bryne. All the samples were subjected to toluidine-blue staining and MCD was determined in 10 fields at ×40. The results were analyzed using one-way ANOVA (α=0.05). Means ± standard deviations of MCD in low-, intermediate- and high-grade tumors were 42.07±23.45, 33±20.32 and 24.92±15.81 according to Broder; 36.08±27.88, 34.38±19.85 and 27±6.32 based on Bryne and 33.25±26.35, 33.50±18.99 and 34.46±21.92 using the Anneroth system, respectively. There were no significant differences in MCD between different OSCC grades in any of the three grading systems (p value = 0.11, p value = 0.68, p value = 0.99). Based on the results of the present study, there is no relationship between MCD in OSCC and the tumor grade in the three grading systems evaluated in this study.

Statins are used as cholesterol-lowering drugs by many patients and have been recently shown to affect bone metabolism. The aim of this study was to determine the effect of atorvastatinon on orthodontic tooth movement (OTM) in rats. Thirty-six adult male Sprague-Dawley rats were randomly divided into three groups of 12 samples each. Group A, served as control with no medication while groups B and C received a daily gavage of carboxymethyl cellulose (CMC) as vehicle and atorvastatin (5 mg/kg) as test substance, respectively. In all three groups, 6mm nickel-titanium closed-coil springs were ligated between the maxillary incisors and first left molars to deliver an initial force of 60g. Tooth movement was measured following sacrifice, 21 days after appliance insertion. Root resorption, PDL width and osteoclast number were histologically evaluated and compared between the groups. The mean amount of tooth movement was 0.62 mm in group A, 0.59 mm in group B and 0.38 mm in group C. OTM reduction following administration of atorvastatin was statistically significant (p<0.05), but there was no significant difference in the studied histologic variables among the three groups (p>0.05). According to the results obtained in the current study, atorvastatin appears to reduce tooth movement in rats; however its effect on osteoclasts, especially osteoclastic function, requires further investigation.

Sj?gren’s syndrome is an autoimmune syndrome involving the exocrine glands specially the salivary and lacrimal glands leading to xerostomia and xerophtalmia. This paper presents a case with primary Sj?gren’s syndrome that severe dental caries were the first clinical manifestation. A 42-year-old man was referred to the School of Dentistry, Tehran University of Medical Sciences due to unexplained severe dental decays. After systematic evaluation and consultation with the rheumatologist and the ophthalmologist, the diagnosis of primary sj?gren’s syndrome was suggested and confirmed by serologic and histopathologic study. Primary sj?gren’s syndrome should be considered in the differential diagnosis of patients with early severe dental caries

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.

Eosinophils are suggested to have had participated in neoplastic invasion and metastasis. The aim of the present study was to evaluate eosinophilic infiltration in oral squamous cell carcinoma (OSCC) and assess its correlation with cervical lymph node metastasis and histological grading. This cross-sectional study used 20 OSCCs samples with lymph node metastasis and 20 samples without (NLM) were selected from the files of Tehran Cancer Institute. Hematoxylin-eosin stained sections were used to evaluate the presence of eosinophils in neoplastic tissues and OSCCs grading. Eosinophils were counted in 10 dense- and 10 classic-high-power-fields and graded from 0 to 4. Statistical analysis as well as Mann-Whitney-U and Kruskal-Wallis tests. The largest percentage of cases in OSCCs with and without LNM based on Eosinophil grading was 50% in grade 1 and 70% in grade 2, based on the dense-field count; and 50% in grades 1 and 0 and 70% in grade 1, when using the classic-field counting method, respectively. Eosinophilic infiltration was not significantly different between the two groups (P>0.05). A significant difference in mean Eosinophilic count was observed among the histological grades when using the dense-field method (P=0.004), but not the classic technique (P=0.029). Within limitations of present study it appears that the presence of Eosinophils in OSCC specimens could not be used as a clinical predictor for lymph node metastasis, however further investigation with a larger sample size is required to clarify the role of these inflammatory cells in OSCC cases.

Angiogenesis is known as the outgrowth of new blood vessels from preexisting vasculature and plays an important role in different aspects of tumor growth and metastasis. Microvessel density (MVD) represents angiogenesis in neoplastic tissues and is generally employed as a useful tool for its measurement. The aim of the present study was to evaluate MVD in salivary gland mucoepidermoid carcinomas (MECs) and to assess its relation to histologic grade. In this cross-sectional study, 30 parotid and minor salivary MECs were graded under a light microscope according to the AFIP criteria. All specimens were immunohistochemically stained with monoclonal antibody against CD34. MVD was determined by counting all positively-stained cells or cell clusters in 10 high-power-fields, selected from the most vascularized areas. The results were analyzed using one-way ANOVA and Scheffe post-hoc tests. MVD was expressed as the mean number of microvessels per high-power-field. A statistically significant correlation was observed between MVD and MEC grade (P=0.001). Microvessel density was significantly lower in grades I (11.12) and II (13.66) compared to grade III (23.50) tumors. The difference between grades I and II neoplasms was not significant (P=0.725). According to the results obtained in the present study angiogenesis may have an important role in the pathogenesis of parotid and minor salivary gland MEC and may be useful in the prediction of its biologic behavior.