Evaluation of copper salivary level in oral squamous cell carcinoma, occupationally copper exposed, and its normal population and its association with cytomorphologic changes of oral mucosa.

Background: Oral squamous cell carcinoma (SCC) is one of the most common malignancies in oral cavity. Hence, presenting methods for early diagnosis and find the etiologic factors of oral SCC are important. Saliva analysis can be used to discover various conditions because of its noninvasive methods. Copper as a useful metal has been used by men since ancient times. The level of copper increases when the cancerous changes occur in addition to biopsy, an alternative method for examining oral lesions is exfoliative cytology. The primary objective of this study was to determine the salivary copper level and cytomorphologic changes of oral mucosa among three study groups. Materials and Methods: This cross-sectional study included 15 individuals with oral SCC, 15 workers exposed to copper, and 15 healthy individuals. Saliva samples were collected and analyzed by atomic absorption spectrophotometer. The exfoliative smears were prepared by brush biopsy and stained by Papanicolaou and argyrophilic nucleolar organizer region (AgNOR) staining methods. Data analysis using one-way ANOVA and Kruskal-Wallis test. P < 0.05 was considered significant. Results: There was a significant difference in mean salivary copper (P = 0.008), cytomorphology of oral mucosa, and AgNOR among the three groups (P < 0.001). Conclusion: The results suggested that occupational exposure to copper increases the salivary levels of this element and causes changes in mucosal cells. Since this increase was very high and evidence of nuclear activity was seen in this group and in oral SCC patients, exposure to copper should be considered an important risk factor for oral mucosal changes.

Vascular and Neural Invasion in Oral Squamous Cell Carcinoma: A Study in an Iranian Population.

Background: Among various parameters used to predict the outcome of malignancy, nerve invasion has been widely considered as a sign of aggressive behavior in oral cancers. According to the importance of neural invasion in predicting the outcome of oral squamous cell carcinoma (OSCC), this study aimed to evaluate the prevalence of neural and vascular invasion in OSCC. Materials and Methods: In this descriptive, analytical, and cross-sectional study, paraffin-embedded tissues of 62 OSCC in the health center of surgery and pathology were evaluated (2013-2015). Patients' archives were evaluated and recorded in terms of their age and gender. Hematoxylin and eosin (H&E) slides were then examined by two oral pathologists and scrutinized for the presence of nerve involvement, tumor differentiation, vascular and lymph node invasion, and depth of invasion. Data were analyzed using SPSS version 23, t-test, and one-way ANOVA (P < 0.05). Results: Of 62 tumors, 12 patients showed only nerve invasion, 17 cases had only vascular invasion, and seven patients had both neural and vascular invasion, simultaneously, known as a neurovascular invasion. Furthermore, there was no vascular and neural invasion in 26 cases. There was a statistically significant correlation between vascular and neural invasion and the tumor site (P = 0.045). The highest frequency of neural invasion, as well as vascular invasion, was related to tongue tumors. Conclusion: The relation between neural and vascular invasion in OSCC with tumor's location was statistically significant. Lip and tongue carcinoma had shown more neurovascular invasion without relation to gender, age, and cell differentiation.

The comparative evaluation of CK17 expression in histologic and cytological sections of oral squamous-cell carcinoma using immunohistochemistry.

BACKGROUD: Squamous-cell carcinoma of the mouth accounts for 90% of all oral cancers and despite advances in treatment methods, its 5-year survival rate is reported to be about 68%. This is due to the late diagnosis of the disease and its resistance to radiotherapy and chemotherapy treatments. One of the methods for diagnosing oral lesions is exfoliative cytology, which is a noninvasive method and can be easily carried out in a dental office. AIM: The purpose of this study is to find a method that in addition to being fast, accurate and less aggressive has high value and a good degree of accuracy for diagnosis of oral squamous-cell carcinoma. MATERIALS AND METHODS: In this descriptive-analytical study, 14 patients who were diagnosed with oral squamous-cell carcinoma and 14 specimens from exfoliative cytology of the same tissue before surgery were examined. Immunohistochemically stained specimens were examined by two pathologists simultaneously. Next, five nonoverlapping sections with magnification (×400) and the number of cells stained with the cytokeratin marker 17 are counted and the average percentage of each slide is determined. One-sample t-test is used to analyze the data and significance level in tests is considered 0.05. RESULTS: In examining the diagnostic value of cytology, we concluded that out of 280 affected cells, 211 cells were stained. Therefore, the sensitivity of cytology in the diagnosis of squamous-cell carcinoma of the mouth is 75.4%. In other words, cytology correctly identifies 75.4% of affected cells as affected. Also, the positive predictive value of cytology was 100%.

Evaluating systemic administration effect of propranolol on osseointegration around titanium implants: A histomorphometric study in dogs.

Background: Dental implants are known as a widely accepted and predictable method to replace missing teeth. Many factors, including using a class of drugs, such as ß-blockers, can improve the osseointegration of dental implants. This study aimed to investigate the relationship between administrating propranolol and osseointegration in dental implants. Materials and Methods: This experimental animal study was performed on four native male street dogs of 11-13 kg of weight and 16-20 months of age. The specimens underwent teeth extraction. After that, the dogs were randomly divided into two groups. The first group contains two control dogs which would receive oral saline. The second contains two dogs which would receive oral tablets of propranolol daily. After a period of healing, three titanium implants were inserted in each of speciments' left mandibular quadrant, and treatment was resumed with propranolol and saline administration in case and control group, respectively. After 4 weeks, one of control group dogs and one of case group were anesthetized, and dental implants were removed alongside the peripheral bone marrow using a trephine drill. Meanwhile, the other two dogs (1 control and 1 propranolol administered dogs) were anesthetized after 9 weeks of implant placement, and the same procedure was carried out. Results: Due to the histomorphometric assessment, the mean score of bone implant contact (BIC) in week 4 was significantly higher in case group compared to control one (68.33% vs. 20.22%). In week 9, the mean BIC score was higher in case group compared to control group (68.60% vs. 50.17%); meanwhile, in contrast to week 4, it was not statistically significant. In both case and control groups, the formation of woven and lamellar bone was more significant in week 4 rather than week 9. Conclusion: Administration of systemic ß-blockers can improve dental implants osseointegration process.

Effect of leukocyte and platelet-rich fibrin on free gingival graft healing: A clinical and histological study in rabbits.

Background. Recently, the use of leukocyte- and platelet-rich fibrin (L-PRF) has been recommended due to the presence of various growth factors to increase the success of free gingival grafts (FGG). This study evaluated the effect of using L-PRF in the healing of FGG in rabbits. Methods. Twenty rabbits were randomly divided into two groups. In each group, FGG was performed in two separate sites with or without L-PRF. One of these groups was sacrificed on the 7th day and the other on the 28th day and analyzed in terms of clinical indices, including wound healing, gingi-val thickness (GT), and keratinized tissue width (KTW). Then histologic sections were obtained and stained for type and degree of inflammation and rate of vascular formation analysis. SPSS 22 was used for statistical analysis. Results. The extent of changes in GT, KTW, wound healing index, and vascular formation between the test and control groups was not statistically significant. The difference in the type of inflammation was significant only between the -7day and -28day control groups (P=0.003). The degree of inflammation between the -7day test group and the -28day control group, as well as the -7day and -28day control groups, were statistically significant (P=0.011 and P=0.002, respectively). Conclusion. Using L-PRF with FGG could improve FGG healing compared to using FGG alone, but the results were not statistically significant.

Effect of systemic administration of omeprazole on osseointegration around titanium dental implants: A histomorphometric study in dogs.

BACKGROUND: Dental implants are widely accepted substitutes for replacing missing teeth. Many factors, including the use of specific drugs such as proton-pump inhibitors (PPIs) (omeprazole), can affect the success of dental implantations. The aim of this study was to investigate the relationship between the use of omeprazole and osseointegration of dental implants. MATERIALS AND METHODS: This experimental animal study was performed on eight native male dogs weighted 11-13 kg and aged 16-20 months. The dogs were divided into two groups (receivers and nonreceivers of omeprazole). After extraction of mandibular teeth, treatment was started randomly with the administration of omeprazole and saline. After a 2-month recovery period, six titanium implants were placed in the jaws of all dogs and the administration of omeprazole was continued for 2 weeks. After 4 and 12 weeks, the dogs were anesthetized and dental implants with their bone marrow were removed. The samples were examined histomorphometrically to determine osseointegration. Data were analyzed with two-way ANOVA test for 95% confidence interval. The P value was set at 0.05. RESULTS: In the microscopic examination of the samples in week 4, the levels of bone-implant contact (BIC) in the study group were significantly lower than the control group (46.37 vs. 64.37%). In 12 weeks, BIC was significantly lower than that of the control group (67.33 vs. 82.00%). The type of bone formed in week 4 in both the groups was more woven, and in the 12th week, it was mostly lamellar. CONCLUSION: Systemic administration of PPIs may interfere with osseointegration of dental implants.

Dental team and infection control for the COVID-19: (A short review of the current guidelines).

BACKGROUND: In December 2019, a series of unusual pneumonia has been reported in Wuhan, China. This pneumonia was related to beta-coronavirus cluster which was named COVID-19. The aim of this study is to review the published paper on COVID-19 protections guide lines and attempt to summarize different suggested guide lines in order to help dental/oral healthcare to have better protection against COVID -19. MATERIALS AND METHODS: An electronic literature search was conducted via google scholar, PubMed, and dental associations' of different countries' website using the key word "COVID-19, Dental team, Guide lines and Recommendation".A total of seven guidelines were found suitable to be included in this review. CONCLUSION: Individuals with 'possible' or 'confirmed' COVID-19 should not be seen for routine dental care. Multi-step approach should begin before the patient arrives on the office and includes guidance regarding their arrival and it should be completed duration of the affected patient's presence in the practice. Accurate travel history, fever or history of fever, acute respiratory infection and severe respiratory infection without fever requiring hospitalization should be checked by staff via patients telephoning to make an appointment and finally the primary infection control goal is to prevent transmission of disease. These treatment guidelines are based on very limited evidence from the literature and should be revised as soon as more evidence about the infection control advices for dental team regarding COVID-19.

Immunohistochemically Detection of Angiogenesis in Oral Pre-Cancerous Lesions Compared with Oral Invasive Carcinomas

Background: Angiogenic activity is an important event in oral carcinogenesis. During transition of normal oral mucosa to different grades of dysplasia and to invasive carcinoma, significant increase of vascularity occurs. Angiogenesis can be determined by immunohistochemical assessment of several endothelial cell markers like Endogelin (CD 105), expressed in activated endothelial cells and associated with neovasculature, and the vascular endothelial growth factor (VEGF). This study was conducted to evaluate angiogenic activity in oral precancerous lesions compared with oral invasive carcinomas by immunohistochemical staining of VEGF and CD 105 proteins. Methods: In the present cross-sectional study, 20 normal, 20 pre-cancerous mucosa and 20 oral invasive carcinoma samples were immunohistochemically stained. Positive cells were counted in each section and micro vessel density (MVD) was determined. The data were statistically analyzed by Mann-Whitney and Kruskal-Wallis tests, with a P-value ≤0.05 considered significant. Results: The mean expression value for VEGF was 24.6 in oral invasive carcinoma, 16.4 in precancerous mucosa and 15.5 in normal mucosa, with no significant differences between the latter two. Endoglin was negative in all normal mucosa samples, but had scores of 7.58 for precancerous mucosa and 19.4 in oral invasive carcinoma specimens. MVD was significantly higher in SCC than in dysplastic mucosa. Conclusion: Oral invasive carcinoma has more angiogenic activity in comparison with pre-cancerous lesions and normal mucosa. Given the high expression of CD105 positive vessels in malignant lesions, we can argue that determination of mean vessel density (MVD) by application of the CD105 marker could be a useful parameter to differentiate cancerous from pre-cancerous lesions.

Determination of salivary urea and uric acid of patients with halitosis.

BACKGROUND: Halitosis is the presence of unpleasant or foul smelling breath. The origin of halitosis may be related to both systemic and oral conditions, but a large percentage of cases, about 90%, is generally related to an oral cause. The aim of this study was to compare the concentration of urea and uric acid in patients with halitosis and people without halitosis. MATERIALS AND METHODS: In this case-control study, concentration of urea and uric acid was compared between two groups: (1) persons suffering halitosis (2) control group without halitosis. Each group includes fifty patients. Unstimulated saliva was collected in both groups. Then, concentration of urea, uric acid, and creatinine was determined. The results were statistically analyzed with SPSS software version 14 (SPSS Inc., Chicago, Illinois, USA) by t-test (α = 0.05). RESULTS: Results showed that salivary urea and uric acid concentration in halitosis group were significantly greater than control group (P < 0.05). Salivary creatinine concentration in halitosis group was significantly lower compared to control group (P < 0.05). Salivary urea and uric acid concentration to creatinine ratios were higher in halitosis group than control group, and significant differences between them were existed (P < 0.05). CONCLUSION: According to the results, urea and uric acid concentration show increase in patient suffering halitosis, and this increase may result in oral malodor.

Socket preservation using freeze-dried bone allograft with and without plasma rich in growth factors in dogs.

BACKGROUND: Plasma rich in growth factors (PRGF) and freeze-dried bone allograft (FDBA) are shown to promote bone healing. This study was aimed to histologically and histomorphometrically investigate the effect of combined use of PRGF and FDBA on bone formation, and compare it to FDBA alone and control group. MATERIALS AND METHODS: The distal roots of the lower premolars were extracted bilaterally in four female dogs. Sockets were randomly divided into FDBA + PRGF, FDBA, and control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 4 weeks. Sockets were assessed histologically and histomorphometrically. Data were analyzed by Kruskal-Wallis test followed by Mann-Whitney U-tests utilizing the SPSS software version 20. P < 0.05 was considered statistically significant. RESULTS: While the difference in density of fibrous tissue in three groups was not statistically significant (P = 0.343), the bone density in grafted groups was significantly higher than the control group (P = 0.021). The least decrease in all socket dimensions was observed in the FDBA group. However, these differences were only significant in coronal portion at week 4. Regarding socket dimensions and bone density, the difference between FDBA and FDBA+PRGF groups was not significant in middle and apical portions. CONCLUSION: The superiority of PRGF+FDBA overFDBA in socket preservation cannot be concluded from this experiment.

Systemic effects of fluoxetine on the amount of tooth movement, root resorption, and alveolar bone remodeling during orthodontic force application in rat.

BACKGROUND: Antidepressant drugs such as fluoxetine are of the most commonly used drugs among the public. These drugs may impact the regulation of bone cell functioning, and thus affect orthodontic tooth movement. The aim of this study was to determine the effect of fluoxetine on tooth movements during orthodontic treatment in rats. MATERIALS AND METHODS: In this study, 30 male rats were randomly assigned into two groups and injected with fluoxetine 10 mg/kg (experimental group) and normal saline (control group) for a period of 1-month intraperitoneally 5 times/week. Then, the rats were anesthetized and a nickel-titanium closed-coil spring was placed between the left maxillary first molar and left maxillary central incisors of all samples, and then fluoxetine (experimental group) and normal saline (control group) were injected for another 3 weeks by the same method. After measuring tooth movements, rats were sacrificed, and histomorphometric analyses were conducted and the obtained data were statistically analyzed using independent t-test and the significance was set at 0.05. RESULTS: Following the fluoxetine injection, the mean amount of tooth movements in the experimental group was reduced compared to the control group, which was not statistically significant (P = 0.14). There was no significant difference between the two groups regarding bone apposition rate (P = 0.83), external root resorption rate (P = 0.1), and mean number of root resorption lacunae (P = 0.16). CONCLUSION: Within the limitations of this study, systemic use of fluoxetine may cause insignificant reduction of tooth movement rate in rats; however, this subject needs more evaluations.

Expression of Bcl-2 and epithelial growth factor receptor proteins in keratocystic odontogenic tumor in comparison with dentigerous cyst and ameloblastoma.

BACKGROUND: Keratocystic odontogenic tumor (KCOT) is a developmental odontogenic cyst on which various investigations have been focused due to its biological activities, high tendency to recur and different growth mechanisms in comparison with other cystic lesions. Previous studies have shown different biological and proliferative activities for the lining epithelium of KCOT. The aim of this study was immunohistochemical evaluation of Bcl-2 and epidermal growth factor receptor (EGFR) expression in KCOT compared with dentigerous cyst and ameloblastoma. MATERIALS AND METHODS: Formalin-fixed and paraffin-embedded tissue sections of 16 cases of KCOT, 16 cases of dentigerous cyst and 16 cases of ameloblastoma were immunohistochemically analyzed to determine Bcl-2 and EGFR proteins' expression. Biotin-Stereotavidin method was used. It was observed by two oral pathologists separately, and the data were analyzed by Mann-Whitney and Kruskul-Wallis. P < 0.05 was considered as significant. RESULTS: Regardless of staining intensity, all cases of ameloblastoma and KCOT except dentigerous cases were positively stained for Bcl-2. Expression of Bcl-2 was higher in the peripheral layer of ameloblastoma and basal layer of KCOT. Furthermore, all cases of ameloblastoma and dentigerous cysts except KCOT samples were positively stained for EGFR. Expression of EGFR was higher in the peripheral layer of ameloblastoma and basal layer of dentigerous cysts. CONCLUSION: According to the expression of - Bcl-2 in ameloblastoma and KCOT, and no expression of EGFR in KCOT, it can be concluded that the biological activity and growth mechanisms of KCOT are different compared with other cystic lesions. However, the aggressive potential of KCOT is not as severe as that of a neoplasm such as ameloblastoma.

Clinicopathological study of 229 cases of salivary gland tumors in Isfahan population.

BACKGROUND: Salivary gland tumors are relatively uncommon and they consist of 3-10% of head and neck neoplasms. Most of studies have shown geographic variation in the incidence and histopathologic types of salivary gland neoplasms. The aim of this study was to evaluate the salivary gland tumors in Isfahan for 10 years duration. MATERIALS AND METHODS: In this epidemiological study, 229 medical records of patients with salivary gland neoplasms in Isfahan for 10 years duration (January 2001-December 2011) were reviewed. The clinical data and histopathological features were statistically analyzed using the Chi-square, analysis of variance and Fisher tests; P < 0.05 was considered to be significant. RESULTS: The data showed that salivary gland tumors were most frequent in women. The mean age of patients with benign tumors was 41.26 years and 51.83 years in malignant tumors. Out of 229 salivary gland neoplasms, 127 (55.5%) were benign and 102 (44.5%) were malignant. Most were in parotid (105), followed by the minor salivary glands (95), the submandibular gland (28) and the sublingual gland (1). CONCLUSION: Pleomorphic adenoma is the most common salivary gland tumor and mucoepidermoid carcinoma followed by adenoid cystic carcinoma are the most common malignancy of salivary gland tumors in Isfahan population. Although most of the results of this study were similar to those reported in other populations, some differences were observed.

Comparative evaluation of photodynamic therapy induced by two different photosensitizers in rat experimental candidiasis.

BACKGROUND: Antimicrobial efficacy of photodynamic therapy (PDT) depends on both the photosensitizer (PS) and laser parameters. In the present study, antimicrobial effectiveness of PDT with different concentrations of two PSs was compared. MATERIALS AND METHODS: In this study, we employed fifty-nine 6-week-old male Wistar rats. All except the negative and overall control groups were immunosuppressed and then orally inoculated with a suspension of Candida albicans (9 × 10(8) CFU/ml). At 4 days after oral inoculation, swabbing of tongue dorsum was performed to recover yeast from the tongue before treatment; on the next day, PDT was carried out on tongue dorsums by use of different concentrations of methylene blue (MB) or poly-L-lysine-chlorine (e6) conjugate (pL-ce6) as PS; followed by a 10 min diode laser illumination at 660 nm (n = 6 each). Then, sampling was again performed. The difference between yeast recovery before and after treatment was compared between the groups by one-way analysis of variance test (α = 0.05). After sacrificing the animals, their tongues were surgically removed and processed for histological evaluation of the presence of yeast and tissue reaction. RESULTS: PDT mediated by both PSs, regardless of the type and their concentration, resulted in a significant microbiological and histological reduction in C. albicans counts in comparison with positive control group (P < 0.001). There was no difference in epithelial lesions and inflammatory responses between groups. CONCLUSION: PDT mediated MB or pL-ce6 is a promising approach for treatment of oral candidiasis.

Socket preservation using demineralized freezed dried bone allograft with and without plasma rich in growth factor: A canine study.

BACKGROUND: The accelerating effect of plasma rich in growth factors (PRGFs) in the healing of extraction sockets has been demonstrated by some studies. The aim of the present study was to histologically and histomorphometrically evaluate whether bone formation would increase by the combined use of PRGF and demineralized freeze-dried bone allograft (DFDBA). MATERIALS AND METHODS: In four female dogs, the distal root of the second, third and fourth lower premolars were extracted bilaterally and the mesial roots were preserved. The extraction sockets were randomly divided into DFDBA + PRGF, DFDBA + saline or control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 6 weeks. The extraction sockets were evaluated from both histological and histomorphometrical aspects. The data were analyzed by Mann-Whitney followed by Kruskal-Wallis tests using the Statistical Package for the Social Sciences version 20 (SPSS Inc., Chicago, IL, USA). Significant levels were set at 0.05. RESULTS: The least decrease in socket height was observed in the DFDBA + PRGF group (0.73 ± 0.42 mm). The least decrease in the coronal portion was observed in the DFDBA + PRGF group (1.38 ± 1.35 mm²). The least decrease in the middle surface was observed in the DFDBA group (0.61 ± 0.80 mm²). The least decrease in the apical portion was observed in the DFDBA group (0.34 ± 0.39 mm²). CONCLUSION: The present study showed better socket preservation subsequent to the application of DFDBA and PRGF combination in comparison with the two other groups. However, the difference was not statistically significant.

Investigation of clinicopathological parameters alongside with p53 expression in primary and recurrent keratocysticodontogenic tumours.

BACKGROUND: Keratocysticodontogenic tumor (KCOT) is one of the most common odontogenic cysts and has a high recurrence rate after various treatment methods. Some studies have been conducted to identify the predictive factors of recurrence. In this study, the clinicopathological and immunohistochemical features of primary and recurrent KCOTs are analyzed, including immunohistochemically expression of p53 protein in cyst-lining epithelial cells in order to find more markers to predict the specific behaviour and greater tendency for recurrence. METHODS: In this descriptive analytic study, a total of 78 archived specimens of KCOTs, including 52 primary KCOT with no registered recurrences to date and 26 recurrent KCOT were selected. The clinical data and histopathological features of the epithelial lining and connective tissue wall were analyzed. Immuonohistochemical staining intensity distribution (SID) score for p53-positive cells were calculated for both groups. Results were analyzed by T-test, Chi-square, and Fisher's exact test. RESULTS: There were no statistically significant differences between primary and recurrent cases in terms of age (P = 0.181), gender (P = 0.744), and anatomical location (P = 0.294). In the histopathological assessment, epithelial budding (P = 0.001), daughter cysts (P = 0.013), and odontogenic rests (P = 0.036) were significantly more common in recurrent KCOTs. Immunohistochemical staining for p53 show statistically significant difference between the two groups (P = 0.041). CONCLUSION: In this study, some predictive factors of recurrence of KCOTs such as epithelial budding, daughter cyst and odontogenic rests were found. Furthermore, the evaluation of p53 expression in KCOT at the time of diagnosis was helpful for the prediction of recurrence.

Investigation of clinicopathological parameters alongside with p53 expression in primary and recurrent keratocysticodontogenic tumours

Keratocysticodontogenic tumor (KCOT) is one of the most common odontogenic cysts and has a high recurrence rate after various treatment methods. Some studies have been conducted to identify the predictive factors of recurrence. In this study, the clinicopathological and immunohistochemical features of primary and recurrent KCOTs are analyzed, including immunohistochemically expression of p53 protein in cyst-lining epithelial cells in order to find more markers to predict the specific behaviour and greater tendency for recurrence.

A comparative study of histological grade and expression of Ki67 protein in oral squamous cell carcinoma in young and old patients.

BACKGROUND: Oral squamous cell carcinoma (SCC) is the most common cancer of oral region. The characteristic feature of SCC is invasion of dysplastic epithelium into the connective tissue. Oral SCC is more common in old patients. It is believed that etiology and pathogenesis of SCC in young patients differ from old patients and it is related to different molecular mechanism. In this study, histopathologic differentiation and proliferation activity (by Ki67) in oral SCC lesions of young patient (<40 years) and old patients (>50 years) have been compared. MATERIALS AND METHODS: In a cohort study, Formalin Fixed and paraffin-embedded tissue sections of 20 oral SCC of young patients and 20 oral SCC of old patients were stained by H and E and immunohistochemically by biotin-streptavidin method. They were observed by two pathologists. Histological grade and Ki67 labeling index (LI) were determined. Data were analyzed by t-test and Mann-Whitney. RESULTS: In cases of oral SCC in young patients, 80% were grade I and 20% were grade II and Ki67 LI was 21/5% in this age group. In cases of oral SCC in old patients, 75% were grade I and 25% were grade II and Ki67 LI was 21/6% in this age group. CONCLUSION: Histological and immunohistochemical evidence of this study show that oral SCC of young patients and oral SCC lesions of old patients didn't show any differences in histopathological differention and proliferative activity.