Abstract Objective To evaluate the influence of RORγT inhibition by digoxin on inflammatory changes related to interleukin-17 (IL-17) in the pulp of rats treated with zoledronate (ZOL). Methodology Forty male Wistar rats were divided into a negative control group (NCG) treated with saline solution, a positive control group (PCG) treated with ZOL (0.20 mg/kg), and three groups treated with ZOL and co-treated with digoxin 1, 2, or 4 mg/kg (DG1, 2, and 4). After four intravenous administrations of ZOL or saline solution in a 70-day protocol, the right molars were evaluated by histomorphometry (number of blood vessels, blood vessels/µm2, cells/µm2, total blood vessel area, and average blood vessel area) and immunohistochemistry (IL-17, TNF-α, IL-6, and TGF-β). The Kruskal-Wallis/Dunn test was used for statistical analysis. Results PCG showed an increase in total blood vessel area (p=0.008) and average blood vessel area (p=0.014), and digoxin treatment reversed these changes. DG4 showed a reduction in blood vessels/µm2 (p<0.001). In PCG odontoblasts, there was an increase in IL-17 (p=0.002) and TNF-α (p=0.002) immunostaining, and in DG4, these changes were reversed. Odontoblasts in the digoxin-treated groups also showed an increase in IL-6 immunostaining (p<0.001) and a reduction in TGF-β immunostaining (p=0.002), and all ZOL-treated groups showed an increase in IL-17 (p=0.011) and TNF-α (p=0.017) in non-odontoblasts cells. Conclusion ZOL induces TNF-α- and IL-17-dependent vasodilation and ectasia, and the classical Th17 response activation pathway does not seem to participate in this process.

Resumo O fibroblastoma desmoplásico (FD) é um tumor benigno raro de partes moles de origem fibroblástica e miofibroblástica e sua ocorrência na cavidade oral é rara. Este estudo detalha um novo caso de uma lesão elevada no rebordo alveolar de uma mulher de 59 anos, dolorosa à mastigação. O exame histopatológico mostrou proliferação de células de morfologia fusiformes a estreladas, não encapsulada, em um estroma rico em colagénio e hipocelular. As células tumorais foram forte e difusamente positivas para vimentina e algumas células foram focalmente positivas para α-actina do músculo liso, CD99 e β-catenina. Os exames foram conclusivos para o diagnóstico de FD. O paciente está no período de acompanhamento e nenhuma lesão recorrente foi detetada em um ano. O FD descrito neste relato, apesar de apresentar características clínico-patológicas-imuno-histoquímicas semelhantes aos casos descritos anteriormente, é apresentado em um local oral incomum e associado a sintomatologia dolorosa. A imuno-histoquímica é uma ferramenta importante nos casos de FD nos quais o exame histopatológico não é conclusivo.

Abstract The desmoplastic fibroblastoma (DF) is a rare benign soft-tissue tumor of fibroblastic and myofibroblastic origin, and its occurrence in the oral cavity is rare. This study details a new case of an elevated lesion in the alveolar ridge of a 59-year-old woman, painful during mastication. The histopathological exam showed non-encapsulated stellate-to-spindle cells proliferation in a hypocellular collagen-rich stroma. Tumor cells were strongly and diffusely positive for vimentin, and some cells were focally positive for α-smooth muscle actin, CD99, and β-catenin. The exams were conclusive for DF diagnosis. The patient is in the follow-up period, and no recurrent lesions were detected within one year. Despite having similar clinical, pathological, and immunohistochemical features to the cases previously described, the DF in this report is at an unusual oral site and associated with painful symptomatology. Immunohistochemistry is an important tool in DF cases where the histopathological examination is not conclusive.

ABSTRACT Purpose: To evaluate the effect of a selective cyclooxygenase 2 (COX-2) inhibitor on trigeminal ganglion changes and orofacial discomfort/nociception in rats submitted to an experimental model of dental occlusal interference (DOI). Methods: Female Wistar rats (180-200 g) were divided into five groups: a sham group (without DOI) (n=15); and four experimental groups with DOI treated daily with 0.1 mL/kg saline (DOI+SAL), 8, 16, or 32 mg/kg celecoxib (DOI+cel -8, -16, -32) (n=30/group). The animals were euthanized after one, three, and seven days. The bilateral trigeminal ganglia were analyzed histomorphometrically (neuron cell body area) and immunohistochemically (COX-2, nuclear factor-kappa B [NFkB], and peroxisome proliferator-activated receptor-y [PPARy]). A bilateral nociception assay of the masseter muscle was performed. The number of bites/scratches, weight, and grimace scale scores were determined daily. One-way/two-way analysis of variance (ANOVA)/Bonferroni post hoc tests were used (P < .05, GraphPad Prism 5.0). Results: DOI+SAL showed a reduction in neuron cell body area bilaterally, whereas DOI+cel-32 exhibited a significative increase in neuron cell body area compared with DOI+SAL group (P < 0.05). The ipsilateral (P=0.007 and P=0.039) and contralateral (P < 0.001 and P=0.005) overexpression of COX-2 and NFkB and downregulation of PPARy (P=0.016 and P < 0.001) occurred in DOI+SAL, but DOI+cel-32 reverted this alteration. DOI+SAL showed increase in isplateral (P < 0.001) and contralateral (P < 0.001) nociception, an increased number of bites (P=0.010), scratches (P < 0.001), and grimace scores (P=0.032). In the group of DOI+cel-32, these parameters were reduced. Conclusions: Celecoxib attenuated DOI-induced transitory nociception/orofacial discomfort resulting from trigeminal COX-2 overexpression.

Resumo O objetivo deste trabalho foi avaliar a eficácia do acetato de carvacrila (ACV) e do ACV nanoencapsulado (nACV) sobre nematóides gastrintestinais de ovinos. O ACV foi nanoencapsulado com quitosana/goma arábica e foi analisada a eficácia de nanoencapsulamento (EE), o rendimento, potencial zeta, morfologia das nanopartículas e cinética de liberação em pH 3 e 8. Foram avaliadas as toxicidades aguda e subcrônica em roedores e a redução da contagem de ovos nas fezes (RCOF) de ovinos. Os ovinos foram divididos em quatro grupos (n = 10): G1, 250 mg/kg ACV; G2, 250 mg/kg de nACV; G3, matriz polimérica e G4: 2,5 mg/kg de monepantel. A EE e o rendimento de nACV foram de 65% e 57%, respectivamente. A morfologia das nanopartículas foi esférica, tamanho (810,6±286,7 nm), potencial zeta no pH 3,2 (+18,3 mV) e a liberação de 50% de CVA nos pHs 3 e 8 ocorreu às 200 e 10 h, respectivamente. nACV apresentou DL50 de 2.609 mg/kg. ACV, nACV e o monepantel reduziram a contagem de ovos por grama de fezes (opg) em 57,7%, 51,1% e 97,7%, respectivamente. A contagem de opg de ovelhas tratadas com ACV e nCVA não diferiu do controle negativo (P>0,05). O nanoencapsulamento reduziu a toxicidade do AVC; no entanto, nACV e ACV apresentaram resultados semelhantes na RCOF.

Abstract The objective of this study was to evaluate the efficacy of carvacryl acetate (CVA) and nanoencapsulated CVA (nCVA) on gastrointestinal nematodes of sheep. The CVA was nanoencapsulated with chitosan/gum arabic and the efficacy of nanoencapsulation (EE), yield, zeta potential, nanoparticle morphology and release kinetics at pH 3 and 8 were analyzed. Acute and subchronic toxicity were evaluated in rodents and reduction of egg counts in the faeces (FECRT) of sheep. The sheep were divided into four groups (n = 10): G1, 250 mg/kg CVA; G2, 250 mg/kg nCVA; G3, polymer matrix and G4: 2.5 mg/kg monepantel. EE and nCVA yield were 65% and 57%, respectively. The morphology of the nanoparticles was spherical, size (810.6±286.7 nm), zeta potential in pH 3.2 (+18.3 mV) and the 50% release of CVA at pHs 3 and 8 occurred at 200 and 10 h, respectively. nCVA showed LD50 of 2,609 mg/kg. CVA, nCVA and monepantel reduced the number of eggs per gram of faeces (epg) by 57.7%, 51.1% and 97.7%, respectively. The epg of sheep treated with CVA and nCVA did not differ from the negative control (P>0.05). Nanoencapsulation reduced the toxicity of CVA; however, nCVA and CVA presented similar results in the FECRT.

SUMMARY Oral melanoacanthoma is a mucocutaneous, pigmented, rare, benign, and probably reactive lesion. This paper reports for the first time in the literature a case of multifocal oral melanoacanthoma in a patient diagnosed with Addison’s disease and concomitant Graves’ disease with hyperthyroidism. The patient presented with oral pigmented lesions, which were hypothesized to be mucosal pigmentation associated with Addison’s disease. Due to their unusual clinical pattern, these oral lesions were biopsied and diagnosed as oral melanoacanthoma on histopathology and immunohistochemistry for HMB-45. At the moment of this report, the patient was being treated for her systemic conditions, but the lesions had not regressed. Reactive hyperpigmentation of the skin and mucous membranes may be found in Addison’s disease and hyperthyroidism. This case reinforces the hypothesis of a reactive nature for oral melanoacanthoma and highlights the need for investigation of endocrine disorders in patients with multifocal oral melanoacanthoma.

ABSTRACT Diabetes mellitus (DM) is a disease associated with delayed wound healing of oral ulcers by increased expression of proinflammatory cytokines and cellular apoptosis. Objective to evaluate the influence of Tumor Necrosis Factor alpha (TNF-α) and apoptosis in rats with DM treated with chamomile extract or triamcinolone. Material and Methods Wistar male rats (210.0±4.2 g) were divided into five groups: negative control group (NCG) without diabetes; positive control group (PCG) with DM (alloxan, 45 mg/kg); and groups treated with chamomile extract (normoglycemic= NCG group and diabetic= DCG group) and with triamcinolone (TG). Traumatic ulcers were performed on all animals that received topical triamcinolone, chamomile extract or saline 12/12 hours for ten days. Results On days five and ten the animals were euthanized and the ulcers were analyzed by light microscopy, TUNEL assay, and immunohistochemically (TNF-α). The NCG (p=0.0062), PCG (p=0.0285), NCG (p=0.0041), and DCG (p<0.0001) groups were completely healed on the 10th day, however, there was no healing on the TG (p=0.5127) group. The TNF-α expression showed a significant reduction from the 5th to the 10th day in NCG (p=0.0266) and DCG (p=0.0062). In connective tissue, the TUNEL assay showed a significant reduction in the number of positive cells in NCG (p=0.0273) and CNG (p=0.0469) and in the epithelium only in CDG (p=0.0320). Conclusions Chamomile extract can optimize the healing of traumatic oral ulcers in diabetic rats through the reduction of apoptosis in the epithelium and TNF-α expression.

RESUMO Objetivo: Comparar as condições sistêmicas e orais, além de avaliar as próteses removíveis, associadas aos portadores de Doença Alzheimer e Doença Parkinson, atendidos em dois centros geriátricos situados no município de Fortaleza - Ceará. Métodos: Foram analisados 70 pacientes (entre 57 à 91 anos) com Doença Alzheimer e Doença Parkinson, por meio de avaliação de prontuários neurológicos e exame clinico oral. Tendo sido observadas variáveis de sexo, idade, raça, comorbidades, condições orais e protéticas. Um total de 20 pacientes idosos sem doenças neurológicas consistiu no Grupo Controle. Foi utilizado teste exato de Fischer como análise estatística. Resultados: Em ambos os grupos estudados, a Hipertensão arterial foi a comorbidade mais frequente. Quanto ao exame oral, no grupo com Doença Alzheimer, foi observado que 54.2% apresentou doença periodontal, 34.2% doença cárie. Achados semelhantes foram encontrados em pacientes com Doença Parkinson (31,4%; 22,8% - respectivamente). Entretanto, não foi observada diferença entre os grupos estudados, quanto as manifestações sistêmicas e orais nos dois centros geriátricos (p>0.05). Foi identificado que mais da metade dos pacientes avaliados nesse estudo (57,7%), utilizavam alguma prótese removível, sendo que 86,5% dessas apresentavam-se mal adaptadas, com algum tipo de defeito, principalmente nos idosos Institucionalizados (p= 0.034). Verificou-se, também, diferença estatística na presença de estomatite protética, entre os grupos demência e grupo controle (p= 0.0213). Conclusão: Idosos portadores de Doença Alzheimer e Doença Parkinson tem deficiente saúde bucal, assim como aqueles sem as doenças neurodegenerativas. No entanto, apresentam mais imperfeições e patologias associadas ao uso de próteses removíveis.

ABSTRACT Objective: To compare the general clinical conditions and oral alterations, and also evaluate the prosthesis, in subjects diagnosed with Alzheimer's disease (AD) or Parkinson's disease (PD), attended at two geriatric centers in the city of Fortaleza - Ceará. Methods: 70 patients were analyzed (between 57 to 91 years) with AD and PD, through evaluation of neurological medical records and oral clinical examination. Variables as sex, age, race, comorbidities, oral manifestations and prosthetic conditions were observed. A total of 20 elderly patients without neurological disease consisted the control group (CG). Fisher's exact test and Kruskal-Wallis were used as statistical analysis. Results: In both groups, blood hypertension was the most frequent comorbidity. As for the oral examination in the group with AD, it was observed that 54.2% had periodontal disease, 34.2% caries. Similar results were found in PD patients (31.4%; 22.8% - respectively). However, no difference was observed between the groups, as the systemic and oral manifestations in both geriatric centers (p> 0.05). Was identified more than half of the subjects (57.7%) using dentures, and 86.5% of these had become maladaptive, with some kind of defect. There was statistical difference in the presence of associated oral pathology, denture stomatitis, between dementia and control group (p = 0.0213). Conclusion: Elderly patients with AD and PD have poor oral health, as well as those without neurodegenerative diseases. However, have more defects and disorders associated with the use of removable dentures.

The aim of this study is to share the experience of implementing a network for the diagnosis of oral cancer by integrating primary, secondary, and tertiary oral health care centers and identifying the possible weaknesses of the process. The study also investigated the risks of exposure to the main risk factors for oral and lip cancer and their most common potentially malignant lesions (PML). A quantitative cross-sectional study was conducted in two different regions, with patients seen at a primary health care facility from August 2010 to July 2011. Patients with oral lesions were referred to dental specialty centers for biopsy. Patients with PML were treated in dental specialty centers, and patients with squamous cell carcinoma (SCC) were referred to tertiary health care facilities. The dentists' knowledge of PML and SCC was assessed by an objective questionnaire. A total of 3,965 individuals were examined, 296 lesions were found, and 73 biopsies were performed, of which 13.7% were diagnosed as PML and 9.6% as SCC. Tobacco use and sunlight exposure were associated with SCC (85.7%) and PML (80%), respectively. In total, 55 dentists were assessed. The lesions most commonly recognized as PML were leukoplakia (74%), erythroplakia (57%), and actinic cheilosis (56%). Most dentists (74%) felt incapable of performing biopsies, most likely because of an anxiety towards oral cancer, and 57% had never performed one. The integration of primary and secondary health care enables the diagnosis of PML and SCC and establishes a diagnosis network. However, the inability of most primary care dentists to identify PML and perform biopsies is a weakness of the diagnostic process.

INTRODUÇÃO: A rara ocorrência de neurofibromas orais (NO) gera problemas com relação à caracterização epidemiológica e imuno-histoquímica dessas lesões. OBJETIVOS: Avaliar a expressão celular de diferentes marcadores em NO e revisar dados epidemiológicos reportados na literatura. MATERIAL E MÉTODOS: Estudos clinicopatológico, imuno-histoquímico (marcadores S-100, epithelial membrane antigen [EMA] e CD-34) e histoquímico (método Ziehl-Neelsen modificado) foram realizados em oito casos de NO diagnosticados no Departamento de Patologia e Medicina Legal (DPML) da Universidade Federal do Ceará (UFC), Ceará, Brasil, entre 1994 e 2010. RESULTADOS: Os NO representaram 0,2% das lesões bucais diagnosticadas pelo serviço em 16 anos; mucosa jugal foi a localização mais frequente (71,4%); sete (87,5%) e oito (100%) casos apresentaram positividade para S-100 e CD-34, respectivamente, e nenhum para EMA. Adicionalmente, mastócitos foram identificados em sete casos (87,5%). A revisão de literatura indicou que NO solitários são mais comuns e ocorrem preferencialmente em mulheres, afetando pacientes entre 30 e 40 anos. O rebordo alveolar é a localização intraoral mais comum. CONCLUSÃO: Os marcadores S-100 e CD34 provaram ser de grande valor como ferramentas diagnósticas, diferente da coloração EMA. A identificação de mastócitos na maioria dos casos sugere seu envolvimento na patogênese desse tumor. Os dados clinicopatológicos da revisão de literatura ajudaram no estabelecimento de um perfil epidemiológico mais consistente.

INTRODUCTION: The rarity of oral neurofibromas (ONs) generates problems regarding their epidemiological and immunohistochemical characterization. OBJECTIVES: The aim of this study was to evaluate the expression of different markers in ONs and review epidemiologic data reported in the literature. MATERIAL AND METHODS: Clinicopathologic, immunohistochemical (markers S-100, epithelial membrane antigen [EMA], CD34) and histochemical (modified-Ziehl-Neelsen-method) studies were performed in eight cases of ON diagnosed in the Department of Pathology and Legal Medicine (DPML), Universidade Federal do Ceará (UFC), Ceará, Brazil, between 1994 and 2010. RESULTS: Oral neurofibromas represented 0.2% of the oral lesions diagnosed by our service in 16 years, and the buccal mucosa was the most frequent oral site (71.4%). Seven (87.5%) and 8 (100.0%) cases were positive for S-100 and CD34, respectively, and none for EMA. Mast cells were identified in seven cases (87.5%). The literature search indicated that solitary ONs are more common and occur preferentially in females, affecting patients between 30 and 40 years old. The alveolar ridge is the most commonly involved site. CONCLUSION: S-100- and CD34 markers proved to be of great value as a diagnostic tool, unlike EMA staining. Identification of mast cells in most cases suggests their involvement in this tumor pathogenesis. The clinicopathologic data retrieved from the literature enabled the establishment of a more consistent epidemiological profile.

Sarcomas são tumores raros originados predominantemente do mesoderma embrionário e que apresentam elevado grau de morbidade e mortalidade. OBJETIVO: Realizar estudo retrospectivo dos casos de sarcomas em cabeça e pescoço no período de 1999 a 2008 em três centros especializados. MATERIAL E MÉTODO: A coleta de dados teve base nos prontuários dos pacientes estudados. Para análise estatística, foram utilizados os testes de associações qui-quadrado e o teste z para proporções. RESULTADO: Foram encontrados registros de 36 pacientes, sendo os indivíduos mais acometidos homens adultos, da raça parda, na faixa etária de 20 a 59 anos, com idade média de 39,7. A relação homem/mulher foi de 1,76:1. O tipo histológico mais prevalente foi rabdomiossarcoma e as localizações mais comuns foram face e região cervical. A maior parte da amostra foi de pacientes vivos sem evidência de doença na última consulta, com 41,6% dos casos. As formas mais comuns de tratamento foram a combinação de cirurgia+radioterapia+quimioterapia e cirurgia + radioterapia, com 27,8% dos casos cada. CONCLUSÃO: Os sarcomas apresentam grande variedade histológica e podem acometer diversas localizações. Por se tratar de lesões raras e pouco conhecidas, novos estudos epidemiológicos devem ser realizados para que se aumente o conhecimento sobre a doença.

Sarcomas are rare tumors, mainly stemming from the embryonic mesoderm, with a high grade of morbidity and mortality. OBJECTIVE: To carry out a retrospective study of head and neck sarcoma cases between 1999 and 2008 in three specialized centers in the city of Fortaleza. MATERIALS AND METHODS: Data collection was based on the charts of the patients in the study. For statistical analysis purposes we used the chi-square associations and the z test for proportions. RESULTS: We found records of 36 patients, and the most affected ones were adult brown males, in the age range between 20 and 59 years - mean age of 39.7. The man/woman ratio was 1.76:1. The most prevalent histological type was the rhabdomyosarcoma and their most common locations were the face and the neck. Most of the sample was made up of live patients without evidence of the disease in the last visit - 41.6% of the cases. The most common treatment modes were the combination of surgery + radiotherapy + chemotherapy and surgery + radiotherapy, with 27.8% of the cases each. CONCLUSION: Sarcomas have a great histological variability and may have numerous locations. Since these are rare and not well-known lesions, new epidemiological studies must be carried out in order to enhance our understanding of the disease.

OBJETIVO: Estabelecer um modelo experimental de úlcera traumática em mucosa jugal de ratos para utilização em futuros testes de terapias alternativas. MÉTODOS: Foram utilizados 60 ratos, adultos, machos, pesando entre 250 a 300g. A ulceração na mucosa jugal esquerda foi provocada por meio da abrasão desta com uma lâmina de bisturi número 15. Os animais foram observados por um período de 10 dias, sendo estes pesados e suas escoriações mensuradas. As características histológicas foram analisadas e descritas adotando escores para comparação dos estágios da fase da úlcera. Na análise estatística um valor de p<0,01 foi considerado uma resposta estatisticamente significante em todos os casos. RESULTADOS: Durante os cinco primeiros dias os animais perderam peso ("t" Student - p<0,01). A área da úlcera regrediu linearmente com o tempo, estando quase que completamente cicatrizada ao final de dez dias (ANOVA, pós-teste de Tendência - p<0,0001). Os grupos do 1º, 2º e 3º dias tiveram comportamento semelhante havendo uma diminuição dos escores a partir do 4º dia. CONCLUSÃO: O modelo de úlcera na mucosa jugal de ratos proposto pode ser considerado eficaz, apresentando reprodutibilidade confiável e baixo custo.

PURPOSE: To establish an experimental model of traumatic ulcer in rat cheek mucosa for utilization in future alternative therapy studies. METHODS: A total of 60 adult male rats (250 - 300g) were used. Ulceration of the left cheek mucosa was provoked by abrasion using a nº 15 scalpel blade. The animals were observed for 10 days, during which they were weighed and their ulcers were measured. The histological characteristics were analyzed and scored according to the ulcer phase. In the statistical analysis, a value of p<0.01 was considered a statistically significant response in all cases. RESULTS: During the five first days, the animals lost weight (Student t test, p<0.01). The ulcerated area receded linearly over time and was almost completely cicatrized after 10 days (ANOVA, Tendency posttest, p<0.0001). Groups on days 1, 2 and 3 days displayed similar results, but a decrease in scores were observed after the 4th day. CONCLUSION: The proposed cheek mucosa ulcer model in rats can be considered an efficient, low-cost, reliable, and reproducible method.

OBJETIVO: Avaliar o efeito do bisfosfonato alendronato (ALD) e do metotrexato (MTX) em modelo do carcinossarcoma 256 de Walker na mandíbula de ratos. MÉTODOS: Uma suspensão de células tumorais do carcinossarcoma 256 de Walker (0,1mL), na concentração de 10(6) células/mL, foi implantada nos alvéolos de ratos previamente abertos por exodontia. Os animais foram divididos em grupos e tratados com salina, MTX, ALD e associação do MTX com ALD. Após o sacrifício, os tumores foram medidos e as mandíbulas removidas para exames radiográfico e histológico. RESULTADOS: No exame radiográfico do grupo controle foi verificada área lítica, sem evidência de reparo na região dos alvéolos, e no microscópico, infiltração óssea periférica e central, de pequenas células tumorais com diversas áreas de necrose. Nos grupos tratados com ALD, associado ou não ao MTX, a análise radiográfica mostrou redução da osteólise tumor-induzida com graus variados de radiotransparência na estrutura óssea; enquanto que, na análise histopatológica, trechos de tecido ósseo preservado, com formação de osteóide em meio a células tumorais foram observados. CONCLUSÃO: O bisfosfonato alendronato exerceu um efeito osteoprotetor e induziu neoformação óssea em mandíbulas de ratos implantadas com células de carcinossarcoma de Walker 256. A combinação do metotrexato com o bisfosfonato alendronato foi mais eficaz que o tratamento com os agentes isoladamente no controle do crescimento das células neoplásicas e na estimulação da formação óssea. Sendo assim, essa associação constitui-se uma alternativa de tratamento das neoplasias malignas dos maxilares com invasão e comprometimento ósseo.

PURPOSE: To investigate the effects of bisphosphosnate alendronate (ALD) and metotrexate (MTX) on an experimental model of Walker 256 carcinosarcoma developed in the oral cavity of rats. METHODS Walker 256 carcinosarcoma cell suspension (0,1 mL) containing 10(6) cell/mL was implanted in the alveoli of the first and second molars. The animals were divided and treated with saline, MTX, ALD, and MTX plus ALD. Later, the animals were sacrificed, the tumors were measured and the mandibles were removed for radiographic and histological analysis. RESULTS: In the control group, the radiographic images demonstrated radioluscency with poorly defined borders, and the microscopic examination revealed tumor infiltration into the peripheral and central regions of the bone. Areas of necrosis were commonly seen. In the treated groups with ALD, associated or not with MTX, the radiographic analysis revealed circumscribed tumor-induced osteolysis and various degrees of radiotransparence; while, histologically, preserved bone trabeculae with osteoid formation was observed among malignant cells. CONCLUSION: The bisphosphonate alendronate exherted an osteoprotective effect and induced bone neoformation on the Walker 256 carcinosarcoma inoculated in rat mandibles. The combination of metotrexate with bisphosphonate alendronate is more successful than treatment with the agents alone in controlling the growth of neoplastic cells and in stimulating reactive new bone. Therefore, this may be an alternative treatment to malignant lesions of maxillaries with osteolysis.

OBJETIVO: Estabelecer um modelo experimental de desenvolvimento tumoral na cavidade oral de ratos, permitindo, assim, o estudo da osteólise induzida pelo tumor nos ossos do complexo maxilomandibular como também nas estruturas dentais, através da caracterização histomorfológica da reabsorção óssea e dentária. MÉTODOS: Uma suspensão de células tumorais (0,1mL) do Carcinossarcoma de Walker 256, na concentração de 10(6) células/mL foi implantado na cavidade alveolar de ratos previamente aberta por exodontia. Os animais foram observados durante 12 (doze) dias consecutivos para determinação da curva de peso corpóreo, sendo posteriormente sacrificados e as mandíbulas removidas para exames radiográfico e histológico. RESULTADOS: No exame radiográfico foi verificada área lítica, sem evidência de reparo, na região dos alvéolos. No exame microscópico foi identificada infiltração óssea, periférica e central, de pequenas células hipercromáticas e pleomórficas, com leve infiltrado inflamatório mononuclear associado e áreas de necrose. O índice de pega foi de 100%. CONCLUSÃO: O modelo animal de invasão óssea, do tumor de Walker na cavidade oral, possibilita a avaliação in vivo de drogas antitumorais e esquemas terapêuticos no tratamento do câncer bucal.

PURPOSE: To estabilish an experimental model of tumor development in the oral cavity of rats, that would enable to study the tumor-induced autolysis in the maxillomandibular bone complex as well as of the dental structures, through histomorphological characterization of bone and dental resorption. METHODS: Walker 256 carcinossarcoma cell suspension (0,1 mL containing 10(6) cell/mL) was implanted in the alveoli of first and second molars. The animals were observed during twelve consecutive days and the body weigth were determined. Later, the animals were sacrificed and their mandibles removed to radiographic and hystologic analysis. RESULTS: The radiographic image demonstrated radioluscencies with poorly defined borders. Microscopic examination revealed the tumor infiltration into the peripheral and central regions of bone.The tumor was composed predominantly of small cells with hyperchromatic nuclei which were occasionally pleomorphic. Areas of necrosis were commonly seen and chronic inflammatory cell infiltration was variable. The index of tumor incidence was 100%. CONCLUSION: The animal model of bone invasion of Walker 256 tumor permits the evaluation in vivo of new chemotherapic drugs in the treatment of oral cancer.