The efficacy of photodynamic therapy in rat tongue dysplasia

Photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) has previously shown promising results in cancerous cell destruction. The present study was conducted to evaluate the efficacy of this treatment option on oral epithelial dysplasia in Wistar rats. Furthermore, microscopic effects of systemic versus topical administration of ALA before laser illumination was assessed. Thirty male Wistar rats (200- 250 grams) were used in the present study. Tongue dysplasia was induced by a daily delivery of a 20 ppm solution of 4-nitroquinoline -1- oxide (4NQO) for 3 months. Then, rats were divided into 3 groups of 10 including, group 1 that was received systemic ALA-based PDT (30 mg/kg ALA), group 2 that was received topical ALA-based PDT (20% ALA solution) and group 3 (control) which was left untreated. Tongue specimens were fixed for histopathological evaluation and dysplasia was graded at microscopic level. Data was compared between various treatment groups using Mann Whitney test (p<0.05). The rate of atypical dysplastic cells was decreased significantly in both topical (p= 0.006) and systemic (p= 0.001) treatment groups compared to control group. Furthermore, systemic use of ALA resulted in a remarkable destruction of dysplastic cells compared to its topical application (p=0.045). Nevertheless, some evidence of muscle destruction was documented in systemic ALA group. It seems that ALA mediated PDT is an effective treatment option for the destruction of dysplastic cells. However, the extent of this effect depends on the mode of ALA administration before light illumination

Detection of Candida albicans in oral squamous cell carcinoma by fluorescence staining technique

Background: One of the probable etiologic risk factors of oral squamous cell carcinoma (OSCC) is Candidal infection, especially by Candida albicans, whose role has not definitely been confirmed. Some have assigned a primary role to Candida, whereas others consider it as a transient inhabitant. The debate may be due to lack of an accurate and sensitive revealing technique. By identifying the presence of Candida, especially in deeper parts of OSCC, the etiologic role may be verified. The present study was conducted to detect the presence of Candida in OSCC by fluorescence staining technique. Materials and Methods: This study was descriptive experimental. Calcofluor-white, which is applied in fluorescence staining, is a specific staining substance for Candida and has a higher accuracy compared with other common methods. 100 specimens of well-differentiated OSCC with adequate amount of tissue were retrieved from the archive and two serial sections were obtained from each one. The first section was stained using the popular histochemical (periodic acid-Schiff [PAS]) method and then evaluated under a light microscope to detect the presence of Candida. The second section was stained using fluorescence staining technique. The sum of counted Candida in each technique was fed into SPSS software and analyzed by McNamara test. P < 0.001 was considered as significant. Results: The amount of Candida present in OSCCs was 74% measured by fluorescence technique. The sensitivity and specificity of the two staining techniques were significantly different. These parameters in the fluorescence technique were higher than those of the histochemical (PAS) method, confirmed by McNamara test showing significantly different results for them (P < 0.001).The results obtained from the fluorescence technique had higher accuracy compared with the histochemical (PAS) method. Conclusion: Some researchers couldn′t find a considerable number of fungi in OSCC, while our results revealed more presence of Candida, especially in deeper parts of tissue samples and probably a more important role for Candida as an etiologic risk factor for OSCC. However, since the fluorescence technique had a higher accuracy in the identification of Candida and it was nearly evident in two-third of the samples, the role of fungi as a primary cause is suggested to be studied in future investigations

Comparative immunohistochemical analysis of angiogenesis and mast cell density in oral normal mucosa and squamous cell carcinoma

Background: Squamous cell carcinoma (SCC) is the most common malignancy in oral cavity. Angiogenesis is essential for the development and progression of SCC. Recently, some studies have reported that mast cells may play a role in tumor progression via promoting angiognesis. Since the results of various studies on the role of mast cells in tumor progression is not uniform, the aim of this study was to define the possible role of mast cells in the process of angiogenesis by determining the microvessel density (MVD) and mast cell density (MCD) and the association between them in oral normal mucsoa and oral SCC. Materials and Methods: In this retrospective analytical study, paraffinized specimens from 22 cases of normal mucosa and 20 cases of well-differentiated oral SCC were selected. Microvessels were stained by using immunohistochemical technique with anti-CD34 antibody and mast cells with toluidine blue and then were counted at 400× magnification in hot-spot areas under a light microscope. The results were analyzed by using t- test and Pearson′s exams. P values less than 0.05 was considered to be significant. Results: A significant correlation was noted between MVD and MCD in normal oral mucosa (P<0.001), but in spite of a higher density of mast cells and microvessels observed in oral SCC compared to normal mucosa, there was no significant correlation between them (P=0.731). Conclusion: These findings showed that factors other than mast cells may play a role in the upregulation of tumor angiogenesis in oral SCC

Intraosseous neurilemmoma of the mandible: Report of a rare ancient type

The neurilemmoma is a benign neoplasm of Schwann cell origin. One of the histopathologic subtypes of this tumor is ancient schwannoma which is characterized by degenerative alterations including cystic change, calcification, hemorrhage, and hyalinization. Intraosseous schwannomas especially ancient ones are rare tumors. Here we present a case of intraosseous ancient schwannoma in the lower jaw of an 11-year-old girl which caused a non-tender expansion. Radiographic examination showed a well-circumscribed, unilocular radiolucent lesion with thin sclerotic borders in the mandibular body and the ramus. Histopathologic examination of the incisional biopsy showed areas of typical Antoni A with verocay bodies and Antoni B that was strongly suggestive of a schwannoma. Complete excision of the lesion was done under general anesthesia. The histopathologic examination confirmed the primary diagnosis and also degenerative changes such as hyalinization and calcification. Based on these findings, the diagnosis of ancient schwannoma was made. No recurrence was observed in the follow-up examination after 3 months

A retrospective comparative study on clinico-pathologic features of oral lichen planus and oral lichenoid lesions

Introduction: Oral Lichen Planus (OLP) and Oral Lichenoid Lesions (OLLs) are clinically and histopathologically similar lesions but with different etiologies and treatment plan, thus differentiating these two has been the center of many researches. Studies in different populations have been performed on clinical and histopathologic features of OLP and OLLs. Thus aim of the present study was to evaluate and also compare the clinical and histopathologic features of these two diseases in a 10-year period in Esfahan. Materials and Methods: This descriptive-analytic study was based on retrospective survey of 232 records with clinical and histopathologic diagnosis of OLP and OLLs available from archive of oral pathology, Esfahan dental school 2000-2010. Data was statistically analyzed by use of independent t-test, Fisher exact, and Chi-square. Results: Involvement of lip was the only clinically significant difference between OLP and OLLs, most seen in OLLs. Band-like inflammatory infiltrate mainly composed of lymphocyte, saw toothed rete ridges, Max Joseph space, and atrophic epithelium was significantly seen in OLP. While hyperkeratosis, deep connective tissue infiltrate composed of eosinophil, neutrophil, and plasma cell were seen in OLLs. Conclusion: Involvement of lip was the only clinically significant difference between OLP and OLLs. Histopathologically strict band like infiltration, atrophic epithelium, saw toothed rete ridges, and Max Joseph space are reliable criteria for differentiation of OLP as deep connective tissue infiltration and hyperparakeratosis are for diagnosis of OLLs

Mast cells distribution and variations in epithelium thickness and basement membrane in oral lichen planus lesion and oral lichenoid reaction

Background: Oral lichen planus (OLP) is a chronic mucocutaneous lesion with unknown etiology. Oral lichenoid lesions (OLL) comprise a family of lesions with different etiologies. Both lesions have similar clinical and histopathologic characteristics although their management is different. Differential diagnosis between OLP and OLL has always been a major challenge. Materials and Methods: In this prospective analytical study, the role of mast cells in pathogenesis of these lesions was investigated by evaluation of 52 patients with clinical and histopathological diagnosis of OLP (26 cases) and OLL (26 cases) based on WHO criteria, and by applying a more accessible staining methods, Hematoxylin and Eosin, toluidine blue (histochemistry) and Periodic Acid Schiff staining. In order to distinguish these two lesions, number of mast cells and thickness of epithelium and basement membrane were measured using light microscopy. Data were analyzed by SPSS software using t-test method (P<0.001). Results: No significant difference was observed between the total numbers of mast cells of two groups (P=0.148), but a statistically significant difference was detected between degranulated mast cells in two groups (P<0.001). A significant difference was also observed between the thickness of epithelium in two groups (P<0.001), although no difference was seen between basement membrane thickness in these lesions. Conclusion: Number of degranulated mast cells in reticular layer of corium in lichenoid lesions was more than that of OLP. This implies that despite the increase in number of these cells, in both groups of diseases, the role of these cells has not been the same in pathogenesis of the diseases. Moreover, the epithelium thickness was lower in lesions of OLP compared to lesions of oral lichenoid, so this parameter may be a useful criterion together with other histopathological and clinical finding to discriminate these lesions. However, discrepancy of basement membrane thickness can not be a reliable criterion. Finally we suggest more accessible staining methods which are reliable for differentiation of these two lesions

Multiple Mucous Retention Cysts (Mucocele) of the Oral Mucosa: A Case Report

To our knowledge, the occurrence of multiple mucoceles is not very common. This case report presents a 62-year-old man with multiple nodules on the upper and lower labial mucosa as well as both buccal mucosae with unknown history. Histopathology evaluation showed minor salivary gland ducts dilated to the point of cyst formation. The cysts seemed to be formed either as a result of dilatation of salivary ducts due to altered secretion or because of an acquired or congenital weakness in the ductal structure. The physiopathology of these findings is discussed

Combination of poly L-lactic acid nanofiber scaffold with omentum graft for bone healing in experimental defect in tibia of rabbits Combinação de poli L-ácido láctico nanofibras com enxerto de omento para reparo ósseo em defeito experimental em tíbia de coelhos

PURPOSE: To investigate the osteoconductive properties and biological performance of Poly L-lactic acid (PLLA) with omentum in bone defects. METHODS: PLLA nanofiber scaffolds were prepared via electrospinning technique. Forty four New Zealand white female rabbits randomly divided into three groups of 18 rabbits each. Created defects in right tibias were filled in group I with omentum, in group II with PLLA nanofiber scaffold and in group III with combination of the omentum and PLLA. The same defects were created in left tibia of all groups but did not receive any treatment (control group). Histological and histomorphometric evaluations were performed at two, four and six weeks after the implantation. RESULTS: Histological changes on all groups along with the time course were scored and statistical analysis showed that the average scores in group III were significantly higher than the other groups. CONCLUSION: Histomorphometric analysis of bone healing was shown to be significantly improved by the combined PLLA with omentum compared with the other groups, suggesting this biomaterial promote the healing of cortical bone, presumably by acting as an osteoconductive scaffold.<br>OBJETIVO: Investigar as propriedades de osteocondução e desempenho biológico do ácido L láctico-Poly (PLLA) com omento em defeitos ósseos. MÉTODOS: Andaimes PLLA nanofibras foram preparados via eletrofiação técnica. Cinquenta e quatro coelhos fêmeas Nova Zelândia brancos foram distribuídos aleatoriamente em três grupos de 18 coelhos cada. Defeitos criados em tíbias direitas foram preenchidos no grupo I com omento, no grupo II com PLLA nanofibras e no grupo III com a combinação do omento e PLLA. Os mesmos defeitos foram criados na tíbia esquerda de todos os grupos, mas não receberam qualquer tratamento (grupo controle). As avaliações histológicas e histomorfométricas foram realizadas em duas, quatro e seis semanas após a implantação. RESULTADOS: As alterações histológicas em todos os grupos, juntamente com o curso de tempo foram marcados e análise estatística mostrou que as pontuações médias do grupo III foram significativamente mais elevadas do que os outros grupos. CONCLUSÃO: Análise histomorfométrica da cicatrização óssea mostrou-se significativamente melhor com o PLLA combinado com omento em comparação com os outros grupos, sugerindo que este biomaterial promove a cicatrização do osso cortical, provavelmente atuando como osteocondutor

Assessment of the effect of diode laser therapy on incisional wound healing and expression of iNOS and eNOS on rat oral tissue

Background: The aim of this study was to compare the effects of diode laser irradiation on wound healing in oral rat mucosa and also to measure the amount of inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) on oral wound healing. Healing was assessed by histology and the amounts of eNOS and iNOS were measured by real-time polymerase chain reaction (PCR). Materials and Methods: Twenty-four standardized incisions were carried out on the buccal mucosa of 12 male Wistar rats; each rat received two incisions on the opposite sides of the buccal mucosa by using a steel scalpel. On the right side (test side), a diode laser (660 nm) was employed on the incision for 10 seconds on days 1-4 and 6-9. The left side (control side) did not receive any laser. Histological and real-time PCR analysis were done on tissue samples after 2, 7, 14, and 21 days. Results: Histological analysis showed that the tissue healing after seven days on the laser irradiated side was better than the control side, but there was no significant difference between the two sides on days 2, 14, and 21 after surgery. Paired t-test analysis showed that there was no significant difference in the amount of eNOS between the groups. The difference in the amounts of iNOS between the groups was significant; it was more in the laser-irradiated side than the control side. Conclusion: Histological findings showed that diode laser needs several repeated irradiations for the acceleration of wound healing. The iNOS amount showed that increases are associated with better healing