Decalcification-free technique on the analysis of dental pulp tissue: histological and immunohistochemical analysis.

BACKGROUND: Histological techniques are essential for the microscopic study and investigation of the human dental pulp. The aim of this study was to evaluate the impact of decalcification-free technique by examining dental pulp morphology by histological staining with haematoxylin and eosin and immunohistochemistry. MATERIALS AND METHODS: The sample consisted of 30 healthy third molars extracted for orthodontic indication, the pulp tissue was obtained by removing the mineralized tissues, separating the enamel and dentine and by marking with a flexible diamond disc on the coronal surface and longitudinal axis of the root. These guides made it possible to separate the fragments and obtain the pulp tissue for fixation and staining with H&E and subsequent immunohistochemistry with CD34 and S-100 antibodies. RESULTS: The technique showed preservation of pulp morphology with adequate preservation of microscopic structures. No alterations in tissue viability were observed. The staining allowed an accurate assessment of vascular and nervous components by means of CD34 and S-100 markers, respectively. CONCLUSIONS: This technique allows preservation of pulp tissue, maintaining viable tissue for histological analysis and immunohistochemistry tests, as well as reducing sample processing time.

Use of Electropolishing in Orthodontic Appliances: An Option to Reduce the Risk of Metal Hypersensitivity.

Electropolishing is a common treatment in the industry; however, how it behaves in the mouth and what benefits it can bring over metal dental attachments have not yet been established. Thus, the aim of this study was to determine the levels of corrosion, the released metal ions, and the changes in structural composition in metallic orthodontic appliances following electropolishing treatment. This study included 56 orthodontic brackets and 28 archwires. The samples were subjected to a pH cycle to simulate an oral environment. Using UV-Vis spectrophotometry, the release of metallic particles was evaluated, and using scanning electron microscopy, the structural and composition changes were evaluated. Groups were compared using Student's t-tests with a value of p ≤ 0.05. The cyclical pH solutions showed variations between groups and days (1, 3, 5, 7 and 15), reaching the highest acidification in the self-ligating brackets; the absorbance between solutions did not differ significantly. As seen from the SEM results, the experimental group showed minor irregularities compared with the control groups. The experimental brackets decreased in iron and increased in chromium after electropolishing, while for the NiTi archwires, they decreased in nickel. Therefore, electropolishing treatments in metallic orthodontic attachments improve their surface structure and corrosion resistance could reduce the risk of metal hypersensitivity, mainly from nickel.

Extranodal natural killer/T cell lymphoma nasal type simulating osteoradionecrosis with metachronic B lymphoma in the pelvis: Case report.

Extranodal Natural Killer/T Cell Lymphoma Nasal Type (EN-NK/T-CL-NT) is a non-Hodgkin extranodal lymphoma of unfavorable prognosis due to its aggressive nature. This neoplasm mainly affects the paranasal sinuses, nasopharynx, oropharynx, oral cavity, palate, and rarely intestinal, gastric and skin regions. 50-year-old female with a history of lymphoma in nasal and pelvic region. At four years of tumors-free, has facial asymmetry, accompanied by sub-palpebral, nasal and lip edema. Intraoral examination revealed a large ulceration suggestive of osteoradionecrosis. Gum biopsy shows Extranodal NK/T Cell Lymphoma Nasal Type (EN-NK/T-CL-NT). In this case we highlight the characteristics of EN-NK/T-CL-NT with a presentation of osteoradionecrosis-like. Unfortunately, the nature of this tumor led to the patient's death. Clinical follow-up of patients with cancer is imperative to mend and/or decrease treatment complications, as well as to identify second primary tumors or the spread of the underlying disease.

Healing of Recurrent Aphthous Stomatitis by Non-Thermal Plasma: Pilot Study.

Recurrent aphthous stomatitis (RAS) is a common disease in the oral cavity characterized by recurrent ulcers (RU). Usually, these cause acute pain without definitive treatment. The present study determines the efficacy of non-thermal plasma (NTP) for treating RU. NTP is applied to the patient's RU using a radiofrequency generator connected to a point reactor. The power density applied to the ulcer is 0.50 W/cm2, less than 4 W/cm2, which is the maximum value without biological risk. Each patient received two treatments of three minutes each and spaced 60 min apart at a distance of 5 mm from the RU. From a sample of 30 ulcers in patients treated for RU with an average age of 37 years, they stated that the pain decreased considerably and without the need for ingestion of analgesics and antibiotics. Regeneration took place in an average of three days. The NTP proved to be an excellent therapeutic alternative for the treatment of RU since it has a rapid effect of reducing pain and inflammation, as well as adequate tissue regeneration.

Mechanical Properties and Antibacterial Effect on Mono-Strain of Streptococcus mutans of Orthodontic Cements Reinforced with Chlorhexidine-Modified Nanotubes.

Recently, several studies have introduced nanotechnology into the area of dental materials with the aim of improving their properties. The objective of this study is to determine the antibacterial and mechanical properties of type I glass ionomers reinforced with halloysite nanotubes modified with 2% chlorhexidine at concentrations of 5% and 10% relative to the total weight of the powder used to construct each sample. Regarding antibacterial effect, 200 samples were established and distributed into four experimental groups and six control groups (4 +ve and 2 -ve), with 20 samples each. The mechanical properties were evaluated in 270 samples, assessing microhardness (30 samples), compressive strength (120 samples), and setting time (120 samples). The groups were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy, and the antibacterial activity of the ionomers was evaluated on Streptococcus mutans for 24 h. The control and positive control groups showed no antibacterial effect, while the experimental group with 5% concentration showed a zone of growth inhibition between 11.35 mm and 11.45 mm, and the group with 10% concentration showed a zone of growth inhibition between 12.50 mm and 13.20 mm. Statistical differences were observed between the experimental groups with 5% and 10% nanotubes. Regarding the mechanical properties, microhardness, and setting time, no statistical difference was found when compared with control groups, while compressive strength showed higher significant values, with ionomers modified with 10% concentration of nanotubes resulting in better compressive strength values. The incorporation of nanotubes at concentrations of 5% and 10% effectively inhibited the presence of S. mutans, particularly when the dose-response relationship was taken into account, with the advantage of maintaining and improving their mechanical properties.

Antimicrobial Activity of Biogenic Silver Nanoparticles from Syzygium aromaticum against the Five Most Common Microorganisms in the Oral Cavity.

Syzygium aromaticum (clove) has been used as a dental analgesic, an anesthetic, and a bioreducing and capping agent in the formation of metallic nanoparticles. The main objective of this study was to evaluate the antimicrobial effect in oral microorganisms of biogenic silver nanoparticles (AgNPs) formed with aqueous extract of clove through an ecofriendly method "green synthesis". The obtained AgNPs were characterized by UV-Vis (ultraviolet-visible spectroscopy), SEM-EDS (scanning electron microscopy-energy dispersive X-ray spectroscopy), TEM (transmission electron microscopy), and ζ potential, while its antimicrobial effect was corroborated against oral Gram-positive and Gram-negative microorganisms, as well as yeast that is commonly present in the oral cavity. The AgNPs showed absorption at 400-500 nm in the UV-Vis spectrum, had an average size of 4-16 nm as observed by the high-resolution transmission electron microscopy (HR-TEM), and were of a crystalline nature and quasi-spherical form. The antimicrobial susceptibility test showed inhibition zones of 2-4 mm in diameter. Our results suggest that AgNPs synthesized with clove can be used as effective growth inhibitors in several oral microorganisms.

Mesiodens en dentición temporal y mixta: informe de casos / Mesiodens in primary and mixed dentition: case reports

Objetivo: Presentar una serie de casos clínicos de me- siodens en niños con dentición temporal y mixta, su trata- miento y seguimiento. Casos clínicos: Se muestra el manejo clínico de tres casos de mesiodens en dentición temporal y un caso en den- tición mixta, los cuales fueron diagnosticados en un examen radiográfico de rutina (AU)

Aim: To present a series of clinical cases of mesiodens in children with primary and mixed dentition, their treatment and follow-up. Clinical cases: This paper describes the clinical man- agement of three cases of mesiodens in primary dentition and one case in mixed dentition which were diagnosed in routine radiographic examinations (AU)

Spongiotic hyperplasia of the oral mucosa: case series and immunohistochemical analysis.

The localized juvenile spongiotic gingival hyperplasia (LJSGH) mainly affects the maxillary vestibular attached gingiva of juvenile patients, without sex predilection. Similar lesions involving extragingival sites have not been reported to date. Here, we report 2 cases of extragingival soft tissue lesions with similar clinicopathological features to those reported in LJSGH and 12 cases of intraoral reactive soft tissue lesions microscopically showing LJSGH-like focal areas. The 2 cases were adult patients, affecting the maxillary alveolar ridge (55-year-old female) and hard palate (78-year-old male), which were diagnosed as "spongiotic hyperplasia of the oral mucosa." The 12 intraoral reactive soft tissue lesions (6 men and 6 women; mean age, 49.5 years) were diagnosed as inflammatory fibrous hyperplasia (n = 6), peripheral ossifying fibroma (n = 3), and pyogenic granuloma (n = 3), each of them presenting LJSGH-like focal areas. By immunohistochemistry, the spongiotic hyperplasia areas showed positivity for CK19, CK14, CK34ßE12, and CAM5.2 (weak/focal), while CK4 was negative. Considering the anatomical locations (extragingival) of these 2 cases, the term "spongiotic hyperplasia of the oral mucosa" is suggested. Moreover, LJSGH-like focal areas can be detected when microscopically assessing common intraoral reactive soft tissue lesions.

Effect of Human Development Index and other socioeconomic factors on mortality-to-incidence ratio of lips and oral cavity cancer in Mexican states: an ecological study.

OBJECTIVES: To assess the association between the Human Development Index (HDI) and covariates on the mortality-to-incidence ratio (MIR) of lips and oral cavity cancer (LOCC) in Mexico. DESIGN: Ecological study. SETTING: Data from 32 Mexican states for year 2019. PARTICIPANTS: Data set of male and female populations from Mexico. EXPOSURES: Socioeconomic conditions based on HDI and covariates related to healthcare system capacity (total health spending per capita, school dropout and ratio of medical personnel in direct contact with patients). PRIMARY AND SECONDARY OUTCOME MEASURES: MIR of LOCC by state and sex was calculated from the Global Burden of Disease Study website for year 2019. Data for calculating HDI 2019 by state and covariates were obtained from the National Institute of Statistics and Geography. A multiple regression model was constructed to measure the effects of HDI and covariates on LOCC-MIR. RESULTS: Among the states with the highest HDI (>0.780), Colima had the highest aged-standardised rates per 100.000 in men for incidence (5.026) and mortality (3.118). The greatest burden of the disease was found on men, with the highest Men:Women MIR in Colima (3.10) and Baja California Sur (2.73). The highest MIR (>0.65) was found among the states with the lowest HDI (Oaxaca and Chiapas). For each unit of increase of the HDI there was a decrease in the LOCC- MIR of -0.778, controlling for the covariates. The most suitable regression model explained the 57% (F (p): 0.000) of the variance. CONCLUSIONS: Men were most affected by LOCC in Mexican states. The highest MIRs of LOCC were found in the states with the highest HDI. But a worse prognosis of the disease, expressed as a higher MIR, is expected in contexts with lower HDI in the country, even with lower MIRs.

COVID-19 pandemic accelerated virtual transformation in dental education: a multicenter review of remote teaching and teledentistry / Transformação virtual acelerada pela pandemia de COVID-19 na educação odontológica: uma revisão multicêntrica do ensino à distância e da teleodontologia

ABSTRACT Although prior to the pandemic there was some resistance to the virtualization of dental education, the COVID-19 pandemic is providing us a unique opportunity to overcome several barriers that previously blocked the adoption of remote teaching and teledentistry. Thanks to the extended availability of telecommunications, digital technologies, and platforms, remote education and teledentistry appear to be the preferred choice to maintain dental education and patient care active under this pandemic, without contamination risks. In this paper, we review valid remote education strategies and possible alternatives useful in virtual transformation in dental education. Furthermore, the role of teledentistry and its advantages and challenges are also revised. Under the current pandemic context, as dental educators, we are called to be creative and flexible. Every dental school should adapt and use remote education as much as possible until clinical attention can be readopted. The evidence presented in this review supports our position that under this pandemic, remote education and telemedicine/teledentistry may be "the virtual convenient solution", to adapt and improve the hitherto classic way of teaching dentistry through tele-education.

RESUMO Embora antes da pandemia houvesse alguma resistência à virtualização da educação odontológica, a pandemia COVID-19 está nos fornecendo uma oportunidade única de superar várias barreiras que anteriormente bloqueavam a adoção do ensino à distância e teledontologia. Graças à ampla disponibilidade de telecomunicações, tecnologias digitais e plataformas, a educação à distância e a teledontologia parecem ser a escolha preferida para manter a educação odontológica e o atendimento ativo aos pacientes durante a pandemia, sem riscos de contaminação. Neste artigo, revisamos estratégias válidas de educação a distância e possíveis alternativas úteis na transformação virtual na educação odontológica. Além disso, o papel do teleodontologia e suas vantagens, assim como também os desafios. No atual contexto pandêmico, como educadores odontológicos, somos chamados a ser criativos e flexíveis. Cada escola de odontologia deve se adaptar e usar a educação à distância, tanto quanto possível, até que a atenção clínica possa ser readotada. As evidências apresentadas nesta revisão corroboram nossa posição de que, sob esta pandemia, a educação a distância e a telemedicina / teleodontologia podem ser "a solução virtual conveniente", para adaptar e aprimorar a forma até então clássica de ensino de odontologia, agora por meio da teleducação.

Evaluation of the release of nickel and titanium under orthodontic treatment.

The metal alloys used in dentistry are made mainly of nickel (Ni), titanium (Ti), and other elements such as molybdenum (Mo), zirconium (Zr), iron (Fe), tin (Sn), chrome (Cr), carbon (C), copper (Cu) and niobium (Nb) which can release metal ions in unstable environments. The aim of this work was determine the salivary pH before and during orthodontic treatment; evaluate the release of metal ions, mainly Ni and Ti, in urine and saliva using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES); and evaluate the corrosion using Scanning Electronic Microscopy (SEM). In this study, we selected 35 individuals under orthodontic treatment, from whom saliva and urine samples were collected in 3 stages: (a) basal, (b) at 3 and (c) 6 months after the placement of the fixed appliances. SEM analyzed the Ni-Ti (0.016″) and stainless steel (SS) (0.016 × 0.022″) archs after 1 month of being in contact with the oral cavity. Statistical analysis was performed with Stata using the ANOVA model of repeated measures with a p < 0.05. A statistically significant difference in the concentration of Ni in saliva were found between 3 and 6 months of intervention and Ti in urine was found 3 and 6 months.

Strategies and operational procedures in oral radiology to mitigate potential SARS-CoV-2 transmission / Estrategias y procedimientos operacionales en Radiología Oral para mitigar transmisión de SARS-CoV-2

SUMMARY Coronavirus disease (COVID-19) is highly transmissible through respiratory droplets, saliva, and aerosol particles. Infection can lead to severe acute respiratory syndrome and trigger multi-organ failure and death. Most clinical dental procedures involve contact with saliva or the generation of aerosols with saliva and blood. These airborne particles increase the risk of transmission by COVID-19 between dentists and patients. Thus, dentistry must adopt procedures to reduce transmission during dental procedures. Although these strategies may not be directly applicable to all institutions due to cultural, social, geographical, and economic differences, the underlying principles and implemented strategies remain relevant and can be adopted or modified by the institutions dealing with the current COVID-19 outbreak. The purpose of this article is to discuss one of the principal sources of COVID-19 transmission: saliva, the biofluid most frequently handled in a radiology environment. The authors also recommend strategies and operational procedures to decrease the spread of COVID-19 in a radiological routine.

RESUMEN La enfermedad por coronavirus (COVID-19) se transmite fácilmente a través de gotitas respiratorias, saliva y partículas de aerosol. La infección puede desencadenar un síndrome respiratorio agudo severo, insuficiencia multiorgánica y, en algunos casos, la muerte. Los procedimientos clínicos dentales determinan el contacto con saliva o la generación de aerosoles con saliva y sangre, lo que implica un alto riesgo de transmisión por COVID-19 entre odontólogos y pacientes. Por ello, la práctica odontologica debe adoptar medidas para detener la propagación durante los procedimientos dentales. En este artículo se revisan las estrategias para mitigar el riesgo de transmisión de COVID-19. Si bien estas estrategias pueden no ser directamente aplicables a todas las instituciones debido a diferencias culturales, sociales, geográficas y económicas inherentes, los principios subyacentes y las estrategias implementadas siguen siendo relevantes y pueden ser adoptados o modificados por las instituciones que se ocupan del brote actual de COVID-19. El propósito de este artículo es discutir una de las principales fuentes de transmisión de COVID-19: la saliva, el biofluido que se maneja con mayor frecuencia en un entorno radiológico. Los autores también recomiendan estrategias y procedimientos operativos para disminuir la propagación de COVID-19 en una rutina radiológica.

Erratum to "Relationship between the Human Development Index and its Components with Oral Cancer in Latin America" [J Epidemiol Global Health 9(4), 2019, 223-232].

DOI of original article: https://doi.org/10.2991/jegh.k.191105.001.

Relationship between the Human Development Index and its Components with Oral Cancer in Latin America.

To evaluate the relationship between the Human Development Index (HDI) and its components with oral cancer (OC) in Latin America. Ecological study in 20 Latin American countries in 2010 and 2017, which evaluated the relationship between the Age-Standardized Rates (ASRs) of incidence and mortality from oral cancer and the following indicators: HDI, with its components (income, education, and health indexes); and the Gini and Theil-L indexes. Among the countries with the highest HDI, men from Brazil and Cuba had the highest incidence and mortality ASRs per 100,000 inhabitants (ASR incidence >7.5 and mortality >4.5). Among those with the lowest HDI, Haiti was the most affected country (ASR incidence >4.1 and mortality >3.0). The highest male:female ratio was in Paraguay in both years (incidence >3.5 and mortality >4.0). Mortality from oral cancer is negatively related to the global HDI in both years, with regression coefficients (95% confidence interval) being -5.78 (-11.77, 0.20) in 2010 and -5.97 (-11.38, -0.56) in 2017; and separate (independent) from the income [-4.57 (-9.92, 0.77) in 2010 and -4.84 (-9.52, -0.17) in 2017] and health indexes [-5.81 (-11.10, -0.52) and -6.52 (-11.32, -1.72) in 2017] (p < 0.05) in the countries with lower HDI. Oral cancer incidence and mortality rates vary both among and within Latin American countries according to sex, with a greater burden on men. The HDI is negatively related to mortality from oral cancer in the countries of medium and low HDI.

Tendencias de la mortalidad por cáncer oral y el efecto de las políticas públicas de prevención en América Latina / Trends in oral cancer mortality and the effect of preventive policies across Latin America

OBJETIVO: Describir las tendencias de la mortalidad por cáncer oral entre 2000 y 2017 por sexos en 20 países de América Latina, e identificar los efectos de las políticas implementadas para controlar de los factores de riesgo. MATERIALES Y MÉTODOS: Se realizó un estudio ecólogico que evaluó la relación entre las tasas estandarizadas por edad de mortalidad por cáncer oral según el sexo, la prevalencia de tabaquismo y consumo de alcohol y la implementación de las políticas públicas de control. RESULTADOS: Los hombres de Cuba y Brasil muestran las más altas tasas de mortalidad en la región. Los descensos más importantes se presentan en los hombres de Brasil y en las mujeres de Panamá. Son pocas las tendencias al aumento, aunque éstas se evidencian especialmente entre las mujeres. La implementación de las medidas de control de factores de riesgo, en cuanto a tabaco, alcohol, infecciones virales, programas de detección temprana y tratamiento, muestra avances desiguales entre los países. Se observó una mayor relación entre la mortalidad por cáncer oral con el consumo de tabaco en los contextos de menor implementación de las políticas, y el consumo de alcohol en los escenarios de mayor avance. CONCLUSIÓN: La mortalidad por cáncer oral afecta especialmente a los hombres de la región, lo que se puede asociar a la distribución de los factores etiológicos y avances desiguales de los países en la implementación de las medidas preventivas. Se requiere profundizar en investigación subnacional de seguimiento, y fortalecer la prevención y tratamiento con estrategias validas para cada contexto.

OBJECTIVE: To describe the trends in oral cancer mortality between 2000 and 2017 by sex in 20 countries in Latin America, and identify the effects of the policies that were implemented to control associated risk factors. MATERIALS AND METHODS: An ecological study was conducted to evaluate the relationship between age-standardized rates of oral cancer mortality by sex, the prevalence of smoking and alcohol consumption, and the implementation of public control policies. RESULTS: Men in Cuba and Brazil show the highest mortality rates in the region. The most important decreases occurred among Brazilian men and Panamanian women. There are only a few cases of increasing trends, although these are especially evident among women. The implementation of risk factor control measures, in terms of tobacco, alcohol, viral infections, early detection programs and treatment, have progressed unevenly in different countries. A strong relationship was observed between oral cancer mortality and tobacco consumption in countries with limited policy implementation; and with alcohol consumption in countries with advanced implementation. CONCLUSION: Oral cancer mortality especially affects men in the region, which can be associated with the distribution of etiological factors and unequal advances in countries in the implementation of preventive measures. It is necessary to further develop subnational follow-up research and strengthen prevention and treatment measures with valid strategies, adapted for each context.

Myoepithelial carcinoma of the retromolar area with extensive mandibular involvement.

Myoepithelial tumors were first described in 1943, and account for less than 1% of all salivary gland neoplasms. Their malignant variant, myoepithelial carcinoma, was first reported by Stromeyer et al. in 1975 and represents a very rare entity, characterized by distinct morphologic heterogeneity and an infiltrative growth pattern into adjacent tissues. However, there have been few reports on myoepithelial carcinoma affecting intra-oral minor salivary glands, and its immunohistochemical features have been poorly illustrated. We herein describe a rare case of myoepithelial carcinoma affecting the retromolar region of a 52-year-old woman that caused extensive mandibular bone destruction. We also reviewed the English literature concerning the involvement of intra-oral minor salivary glands by myoepithelial carcinoma.

Primary oral melanoma: a histopathological and immunohistochemical study of 22 cases of Latin America.

OBJECTIVE: The aim of this study was to analyze the histopathological and immunohistochemical characteristics of 22 cases of primary oral melanomas (OM). STUDY DESIGN: Twenty two cases of primary oral melanoma were analyzed by description of their histopathological features and immunohistochemical study using the antibodies S-100, HMB-45, Melan-A and Ki-67. RESULTS: The mean age was 58 years and 14 cases were female. The main affected sites were the hard palate, followed by the upper gingiva. Microscopically, 15 cases presented level III of invasion, 2 cases were amelanotic and 13 showed a mixed epithelioid and plasmacytoid or spindle cells composition. Some cases showed necrosis, perivascular and perineural invasion. S-100 and HMB-45 were positive in all cases, but 3 cases were negative for Melan-A. The proliferative index with Ki-67 was high, with labeling index ranging from 15.51% to 63% of positive cells. CONCLUSION: S-100 and HMB-45 are more frequently expressed than Melan-A in primary oral melanomas and these markers are helpful to confirm the diagnosis.

Central odontogenic fibroma: new findings and report of a multicentric collaborative study.

OBJECTIVE: The aim of this study was to describe the clinicopathologic and immunohistochemical characteristics of 14 cases of central odontogenic fibroma (COF), and the ultrastructural features of 2 of them. STUDY DESIGN: Collaborative retrospective study based on the records of 4 oral pathology diagnostic services in Latin America based on the current World Health Organization classification. RESULTS: There were 7 male and 7 female patients (mean age 31.8 years). Eight tumors occurred in the maxilla and 6 in the mandible. Thirteen cases were epithelium-rich and 1 epithelium-poor COF. Three were classified as hybrid COF with giant cell lesion. Mean size of the hybrid lesions were larger than pure COF (3.8 vs. 2.4 cm). Odontogenic epithelial islands were immunoreactive for cytokeratin (CK) AE1/AE3, CK5, CK14, CK19, and 34BE12 and negative for CK1 and CK18. Langerhans cells positive for S-100 and CD1a were found within the epithelial islands in 6/6 tested cases. CD68 was expressed in the giant cells of the hybrid lesions and in a few mononuclear cells of 2 cases of COF. Ki-67 index was <1% in all cases. In 6 tumors (42.8%), there were small globular eosinophilic droplets within the epithelial islands, which were positive for collagen type IV, and 9/13 cases (69.2%) were focally positive for smooth muscle actin. In addition to fibroblasts, myofibroblastic differentiation was found in the 2 cases studied ultrastructurally. CONCLUSIONS: Immunohistochemistry was useful to confirm the presence of epithelium and to exclude other central fibrous tumors. COF also contains a variable number of mast cells, Langerhans cells, and myofibroblasts, and further studies are needed to better understand the participation of these cells in COF histogenesis.

Peripheral desmoplastic ameloblastoma: histopathological and immunohistochemical profile of a case.

In this study we present a rare case of peripheral desmoplastic ameloblastoma and discuss its clinical features, histopathology, and immunohistochemical profile. This article reports a new case of this unusual neoplasm in a 66 year-old woman in which the main complaint was an asymptomatic swelling located in the right body of mandible. Histopathological findings were similar to the two previously reported cases of this tumor. Positive immunohistochemical stain for laminin V and type IV collagen suggests an inductive effect of the epithelium over the stroma while the low index of p53 protein and Ki-67 expression in epithelium and stromal cells, as well as CD138 uniform positive-stain in epithelial cells, support the benign biological behavior of this lesion. Including this new case, currently there are only three reports of this rare neoplasm. Reports of new cases of peripheral desmoplastic ameloblastoma are necessary for a better understanding of the origin and behavior of this particular subtype of ameloblastoma.