Micronuclei as an indicator of genotoxic change in epithelial cells of buccal mucosa after panoramic radiographs.

BACKGROUND: The radiation released at the time of dental panoramic radiographs causes genotoxic and cytotoxic effects on epithelial cells. OBJECTIVE: This research aimed to evaluate the changes in the frequencies of micronucleated cells in patients' buccal epithelial cells following dental panoramic radiography. METHODS: 74 patients were recruited for the study who were advised for panoramic radiographs. Using a wooden spatula, the buccal epithelial cells were scraped from both cheeks before to panoramic radiation exposure and ten days after the panoramic radiation exposure. Giemsa stain was used to stain the cells, and 500 cells were scored on a slide to determine the frequency of micronuclei. To determine the difference between the frequency of micronuclei before and after radiation exposure, a paired t-test was used in the statistical analysis. RESULTS: The proportion of micronuclei cells was 0.11% before radiation exposure and 0.57% following radiation exposure after 10 days. A statistically significant increase in the frequencies of micronuclei was noted after radiation exposure values. CONCLUSION: This study revealed the genotoxicity of epithelial cells with dental panoramic radiation exposure. It is advised to reduce the use of such radiographs and to use only when there is no other diagnostic tool that is helpful or when absolutely essential.

Treatment outcomes of oral leukoplakia on the irradiated or nonirradiated mucosa among survivors of head and neck cancer in the papulation where practice of betel nut chewing and cigarette smoking are widespread.

BACKGROUND: Radiotherapy (RT) has numerous effects on the oral mucosa, primarily genetic alterations and changes in the microenvironment. The characteristics of oral leukoplakia (OL) may differ between patients who have received previous head and neck cancer (HNC) treatment with radiation therapy and those who have not. Due to a lack of data on this scenario, we aimed to investigate the surgical outcomes of OL by comparing these two patient groups. METHODS: This retrospective cohort study enrolled a total of 224 OL lesions in 124 patients who underwent carbon dioxide laser (CO2 laser) surgery from July 2002 to Aug 2021. All patients had received previous treatments for HNC, with 59 patients undergoing only surgical approach, 65 patients undergoing RT, and 46 patients undergoing concurrent chemotherapy during RT. The analysis was performed on a per-lesion basis, not a per-capita basis. We investigated the associations of clinicopathological characteristics and treatment outcomes of OL lesions that developed from irradiated or nonirradiated oral mucosa. RESULTS: The median follow-up time was 5.87 years. Postoperative recurrence of OL occurred in 30 patients. Malignant transformation occurred in 17 patients with the incidence rate 4.19% annually and 13.7% cumulatively. The average time for OL transforming into squamous cell carcinoma was 3.27 ± 3.26 years (median 1.82, range 0.11 - 11.90). In univariate analysis, non-homogeneous morphology (P = 0.042), moderate to high-grade dysplasia (P = 0.041), and nonirradiated oral mucosa (P = 0.0047) were predictors for malignant transformation. However, in the Cox proportional hazard model, only nonirradiated oral mucosa remained an independent prognostic factor related to postoperative malignant transformation of OL (P = 0.031, HR 5.08, CI95 1.16 - 22.25). CONCLUSION: In the population whose OL is strongly aetiologically linked to environmental carcinogens such as betel nut and tobacco, OL lesions that develop on previously irradiated oral mucosa have a lower risk for postoperative malignant transformation compared to those that develop on nonirradiated mucosa. This finding highlights the potential impacts of radiation on OL. Further research is needed to confirm this observation and elucidate the underlying mechanism.

Development of an Ex Vivo Functional Assay for Prediction of Irradiation Related Toxicity in Healthy Oral Mucosa Tissue.

Radiotherapy in the head-and-neck area is one of the main curative treatment options. However, this comes at the cost of varying levels of normal tissue toxicity, affecting up to 80% of patients. Mucositis can cause pain, weight loss and treatment delays, leading to worse outcomes and a decreased quality of life. Therefore, there is an urgent need for an approach to predicting normal mucosal responses in patients prior to treatment. We here describe an assay to detect irradiation responses in healthy oral mucosa tissue. Mucosa specimens from the oral cavity were obtained after surgical resection, cut into thin slices, irradiated and cultured for three days. Seven samples were irradiated with X-ray, and three additional samples were irradiated with both X-ray and protons. Healthy oral mucosa tissue slices maintained normal morphology and viability for three days. We measured a dose-dependent response to X-ray irradiation and compared X-ray and proton irradiation in the same mucosa sample using standardized automated image analysis. Furthermore, increased levels of inflammation-inducing factors-major drivers of mucositis development-could be detected after irradiation. This model can be utilized for investigating mechanistic aspects of mucositis development and can be developed into an assay to predict radiation-induced toxicity in normal mucosa.

The features of the reparative regeneration of an oral mucosa wound created under the exposure of a laser at a wavelength of 445 nm (a pilot study).

In clinical practice, an innovative laser technology that provides contactless preparation of soft tissues with a wavelength of 445 nm has been introduced. This study aimed to investigate the morphological changes in the oral mucosa when exposed to laser radiation at a wavelength of 445 nm in the ablation mode.An experimental study was conducted to analyze the dynamics of reparative regeneration in the wound caused by that particular type of radiation, utilizing the procedure of lower lip frenuloplasty as an illustration. 48 sexually mature male laboratory rats were chosen as the research object. The procedure of preparing the oral vestibule was executed by employing a contactless laser beam with a wavelength of 445 nm and a power of 0.7 W in continuous mode (CW) and an uninitiated fiber.Histological examination showed that 25 min after the surgery, there were large areas of coagulation necrosis in the oral mucosa in the area affected by the blue laser. In 48 h, the area of necrosis decreased both in size and depth. By the 7th day after the surgery, the necrotic masses had grown into the connective tissue, while marginal regeneration of the epithelium was noted. By the 14th day, the wound surface was completely epithelialized, represented by fibrous scar tissue. Clinically, around the mandibular incisors, there was a wide area of attached keratinized gingiva.The findings of histological examination indicate a necrosis of coagulation type in the region of tissue ablation and also show the absence of phase II of the inflammatory response (the stage of exudation), which expedites the process of epithelialization of the oral mucosa wound.

A systematic review and meta-analysis of the genotoxic and cytotoxic effects on oral epithelium induced by cone beam computed tomography.

OBJECTIVE: To evaluate the occurrence of genotoxic and cytotoxic effects in oral epithelium after exposure of patients to cone beam computed tomography (CBCT). METHODS: A systematic review (SR) was conducted following the PECO (Population, Exposure, Comparison, Outcome) criteria. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO). A search was performed on the PubMed, Scopus, ScienceDirect, and Google Scholar databases. Effect size and heterogeneity of data were evaluated statistically. The Joanna Briggs Institute questionnaire for observational studies was utilized to assess the risk of bias. The GRADE tool was applied for the assessment of the quality of evidence. Begg's funnel plot was used to evaluate publication bias. RESULTS: In total, 10 full-text articles were included in the SR, with 6 of them in the meta-analysis. The SR showed a significant increase in micronuclei after exposure, with a large effect size of 1.03. For genotoxicity, the tau2 for heterogeneity was 0.96, the chi-squared test for heterogeneity P < .00001, the I2 statistics for random effects was 91%, and the overall effect for Z value was 2.46 (P = .01). The risk of bias was low, the quality of evidence was strong, and publication bias was absent. CONCLUSION: CBCT can cause genotoxicity in the oral epithelium with a large effect size. The measure of cytotoxicity after CBCT exposure was not possible due to the lack of homogeneity of the included articles.

Mobile phone specific radiation disturbs cytokinesis and causes cell death but not acute chromosomal damage in buccal cells: Results of a controlled human intervention study.

Several human studies indicate that mobile phone specific electromagnetic fields may cause cancer in humans but the underlying molecular mechanisms are currently not known. Studies concerning chromosomal damage (which is causally related to cancer induction) are controversial and those addressing this issue in mobile phone users are based on the use of questionnaires to assess the exposure. We realized the first human intervention trial in which chromosomal damage and acute toxic effects were studied under controlled conditions. The participants were exposed via headsets at one randomly assigned side of the head to low and high doses of a UMTS signal (n = 20, to 0.1 W/kg and n = 21 to 1.6 W/kg Specific Absorption Rate) for 2 h on 5 consecutive days. Before and three weeks after the exposure, buccal cells were collected from both cheeks and micronuclei (MN, which are formed as a consequence of structural and numerical chromosomal aberrations) and other nuclear anomalies reflecting mitotic disturbance and acute cytotoxic effects were scored. We found no evidence for induction of MN and of nuclear buds which are caused by gene amplifications, but a significant increase of binucleated cells which are formed as a consequence of disturbed cell divisions, and of karyolitic cells, which are indicative for cell death. No such effects were seen in cells from the less exposed side. Our findings indicate that mobile phone specific high frequency electromagnetic fields do not cause acute chromosomal damage in oral mucosa cells under the present experimental conditions. However, we found clear evidence for disturbance of the cell cycle and cytotoxicity. These effects may play a causal role in the induction of adverse long term health effects in humans.

Comparison of diode laser - Oral tissue interaction to different wavelengths. In vitro study of porcine periodontal pockets and oral mucosa

BACKGROUND: The aim of this in vitro study was to evaluate the effect of diode lasers at different wavelengths and power settings in handmade incisions in periodontal pockets and in oral mucosa of porcine tissue considering thermal damage, necrosis and the affected area of the soft tissue. MATERIAL AND METHODS: Combining the following laser wavelengths, 445 nm, 532 nm (KTP), 810 nm, 980 nm, 1064 nm and 1470 nm, and a power range from 0.5W to 2.0W in a continuous wave mode (CW), we made handmade incisions in porcine periodontal pockets and oral mucosa. After histological processing, we measured the area of lost tissue, the area of thermal damage and the area of necrosis. Then, we performed ANOVA to evaluate the difference between groups and two-way ANOVA to identify the influence of the laser-type variables and the power on the results. RESULTS: We applied an ANOVA test to evaluate the results, where statistical analysis showed clear differences between the 1470nm and 810nm laser groups that refer to thermal damage and necrosis in the periodontal pocket surface. Regarding the oral mucosa surface, the 1064 nm laser showed differences in the analysis of lost tissue. According to the applied power, all the variables we studied (lost tissue area, area of thermal damage and necrosis) showed higher values when using a power of 2.0W instead of 0.5W. CONCLUSIONS: According to our results, the 810nm diode laser for oral soft-tissue biopsy using power ranges between 0.5W and 2W would be the best choice to avoid thermal damage in peri-incisional margins

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Frecuencia de micronucleos en células de la mucosa bucal en individuos expuestos a la radiación electromagnética de teléfonos móviles: un estudio de replicación / Micronucleus frequency in cells of the oral mucosa in individuals exposed to electromagnetic radiation of mobile phones: a replication study

INTRODUCCIÓN: Hasta el momento, los resultados de distintas investigaciones sobre la exposición a Radiofrecuencias y sus consecuencias biológicas, son contradictorios. Nuestro estudio nace como un estudio de replicación, en conjunto con investigadores de la Escuela de Tecnología de la Salud de Lisboa, Lisboa, Portugal. Adoptamos el mismo diseño de estudio, para verificar si los resultados de su evaluación de la frecuencia de micronucleos (MN) en los usuarios de teléfonos móviles eran comparables a los resultados obtenidos en este estudio similar en Córdoba, Argentina. MATERIALES Y METODOS: Para estudiar el daño del ADN por la exposición a radiofrecuencia asociada con el teléfono celular se estudiaron los MN (marcadores celulares de daño genómico) en células bucales exfoliadas, extraídas de frotis de células de las mejillas internas derecha e izquierda de usuarios de teléfonos celulares en 83 voluntarios sanos de 18 a 36 años. Las frecuencias de MN fueron analizadas por la duración y el lado preferencial de uso del teléfono celular. RESULTADOS: no se observó relación entre la frecuencia de MN y la duración del uso como tampoco con el lado preferencial. CONCLUSION: nuestros resultados sugieren que la exposición a radiofrecuencia en los niveles observados no induce la formación de MN en células bucales. (AU)

INTRODUCTION: the results of various research on radiofrequency exposure and its biological consequences are contradictory. Taking into account this reasoning, our study was born as a replication study, together with researchers from the School of Health Technology of Lisbon, Lisbon, Portugal. We adopted the same study design, to verify if the results of your evaluation of the frequency of micronuclei (MN) in cell phone users were comparable to the results obtained in this similar study in Cordoba, Argentina. MATERIALS AND METHODS: To study ADN damage from radiofrequency exposure associated with cell phone, MN (cell markers of genomic damage) were studied in exfoliated buccal cells, extracted from right and left internal cheek cell smears of cell phone in 83 healthy volunteers from 18 to 36 years. RESULTS: The MN frequencies were analyzed by the duration and the preferential side of use of the cell phone. No relationship was observed between the MN frequency and the duration of use as well as the preferential side. CONCLUSION: our results suggest that exposure to radiofrequency in the observed levels does not induce the formation of MN in buccal cells. (AU)

Prospective study of the 532 nm laser (KTP) versus diode laser 980 nm in the resection of hyperplastic lesions of the oral cavity

Background: The aim of this study is to evaluate the resection of hyperplastic lesions on the buccal mucosa comparing the 532nm laser (KTP), versus diode 980nm laser, considering pain, scarring, inflammation and drug consumption that occurred postoperatively with each lasers. Material and Methods: A prospective study of consecutive series of 20 patients in two groups that presents hyperplastic lesions on the buccal mucosa. The choice of the KTP laser or diode 980nm laser for the surgery was made randomly. The power used was 1.5W in both groups in a continuous wave mode with a 320 μm optical fiber. Parameters of pain, scarring, inflammation and consumption of drugs were recorded by a Numerical Rating Scale and evaluated postoperatively. These recordings were made the day of the surgery, 24 hours after, 14 and 28 days after. Results: Pain and inflammation was light - moderate. The consumption of paracetamol was somewhat higher in the diode 980nm laser versus the KTP laser after 24 hours, although data was not statistically significant; significant differences were found after 28 days in regards to pain (p = 0.023) and inflammation (p = 0.023), but always in the absence parameter so we find no pain in both lasers. Scarring in the two types of laser showed no differences along the visits, with not detected scar retractable. Conclusions: Although there is a slight histological difference regarding the KTP laser in the oral soft tissues for clinical use, both wavelengths are very suitable for excision of oral fibroma (AU)

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Osteoradionecrosis of the jaws: case series treated with adjuvant low-level laser therapy and antimicrobial photodynamic therapy

Abstract Background: Osteoradionecrosis of the jaw (ORNJ) is the most severe and complex sequel of head and neck radiotherapy (RT) because of the bone involved, it may cause pain, paresthesia, foul odor, fistulae with suppuration, need for extra oral communication and pathological fracture. We treated twenty lesions of ORNJ using low-level laser therapy (LLLT) and antimicrobial photodynamic therapy (aPDT). The objective of this study was to stimulate the affected area to homeostasis and to promote the healing of the oral mucosa. Methods: We performed aPDT on the exposed bone, while LLLT was performed around the bone exposure (red spectrum) and on the affected jaw (infrared spectrum). Monitoring and clinical intervention occurred weekly or biweekly for 2 years. Results: 100% of the sample presented clinical improvement, and 80% presented complete covering of the bone exposure by intact oral mucosa. Conclusion: LLLT and aPDT showed positive results as an adjuvant therapy to treat ORNJ.

Genotoxicidade e citotoxicidade dos raios x em crianças submetidas à radiografia panorâmica / Genotoxicity and cytotoxicity of x-rays in children exposed to panoramic radiography

RESUMO Objetivo: Analisar a genotoxicidade e a citotoxicidade produzidas por raios X no epitélio da mucosa oral de crianças durante a obtenção da radiografia panorâmica. Métodos: A amostra foi constituída por 30 crianças saudáveis, sendo 19 do sexo feminino e 11 do masculino, com faixa etária de 4 a 10 anos (média de 7 anos de idade). As células epiteliais da mucosa oral foram coletadas por meio de citologia esfoliativa em base líquida imediatamente antes e após sete dias da obtenção da radiografia panorâmica. Os esfregaços foram processados e corados utilizando a técnica de Feulgen Rossenbeck modificada. Foram analisadas e quantificadas projeções nucleares dos tipos bud e broken egg, alterações genotóxicas na forma de micronúcleo e alterações citotóxicas dos tipos picnose, cariólise e cariorrexe. Resultados: A frequência de picnose, bud e broken egg foi significativamente maior após a exposição aos raios X (p<0,05), porém não houve diferença estatisticamente significante em relação ao sexo, bem como nas demais alterações estudadas. Conclusões: A exposição aos raios X emitidos durante a obtenção da radiografia panorâmica pode induzir à morte celular no epitélio da mucosa oral de crianças. Não foi encontrado indício significativo de efeito genotóxico.

ABSTRACT Objective: To assess the genotoxicity and cytotoxicity produced by X-rays in the epithelium of the oral mucosa of infants exposed to panoramic radiography. Methods: The sample consisted of 30 healthy children, 19 females and 11 males, ranging in age from 4 to 10 years (average of 7 years of age). Oral mucosa cells were collected by liquid-based cytology immediately before and after seven days following the exposure to panoramic radiography. Smears were processed and stained using the modified Feulgen Rossenbeck technique. Bud and broken egg nuclear projections, changes in the form of micronuclei, and genotoxic and cytotoxic changes of pyknosis, karyorrhexis and karyolysis were analyzed and quantified. Results: The frequency of pyknosis, buds and broken eggs was significantly higher after exposure to X-rays (p<0.05), but there was no statistically significant difference regarding gender, as well as in the other changes studied. Conclusions: Exposure to X-rays emitted during submission to panoramic radiography may induce cell death in the epithelium of children's oral mucosa. No evidence was found for a significant genotoxic effect.

Expresión de TGFß1 por fibroblastos de mucosa oral expuestos a radiación ultravioleta B / TGF1 expression by oral mucosa fibroblasts exposed to ultraviolet ß1 radiation

El objetivo de este estudio fue evaluar el efecto de la radiación ultravioleta (UV) B sobre la expresión del factor de crecimiento transformante (TGF) ß1 por fibroblastos de mucosa oral, con el objetivo de dilucidar si este tipo celular puede contribuir a la expresión de TGFß1 en bermellón labial sobreexpuesto a la radiación UV. Se obtuvieron cultivos primarios de fibroblastos desde explantes de mucosa bucal, los que fueron irradiados con una dosis única de luz UVB (60 mJ/cm2). Se midió proliferación celular con el método MTT, y la expresión de TGFß1, a nivel de ARN mensajero (normalizado a GAPDH) por RT-PCR y a nivel de proteína mediante inmunofluorescencia. Se observó una disminución de la proliferación celular de los fibroblastos de mucosa oral a las 24 hrs post-irradiación en relación a los fibroblastos no irradiados (P<0,05, Mann Whitney). No se encontraron diferencias entre los fibroblastos control y los irradiados en la expresión de TGFß-1 ni a nivel de mensajero (0,5 y 6 h post-irradiación), ni de proteína (24 h post-irradiación). Los resultados sugieren que los fibroblastos de mucosa oral presentan una disminución de su proliferación en respuesta a una dosis única de radiación UVB, sin que se afecte la expresión de TGFß-1, la que fue similar a los fibroblastos no irradiados. Esto sugiere que los fibroblastos contribuirían a la producción de TGFß-1 en respuesta a la exposición crónica a UVB del bermellón labial.

The objective of this study was to characterize the effect of Ultraviolet (UV) B irradiation on the expression of transforming growth factor (TGF) ß1 by oral mucosa fibroblasts, in order to assess if these cells contribute to the production of TGFß-1 in UV-irradiated lip vermillion. Primary cultures of fibroblasts were obtained from oral mucosa explants, and were irradiated with a single dose of UVB light (60 mJ/cm2). The effects of UVB radiation on cell proliferation was evaluated by the MTT method. The effects of UVB on the expression of TGF-ß1 was analyzed by RT-PCR (normalized to GAPDH) and by immunofluorescence. The results showed a decrease in the proliferation of UVB-irradiated fibroblasts as compared to controls at 24h post-irradiation (p<0.05). No variations in the expression of TGFß1, both at the mRNA and protein level, were observed between control and UVB-irradiated fibroblasts during the first 24 h after irradiation. Oral mucosa fibroblasts have reduced proliferation in response to a single dose of UVB, but their expression of TGFß1 was not affected. This suggests that oral mucosa fibroblasts may contribute to the production of TGFß1 in the lip vermillion independent of UVB exposure.

Láser Doppler y su uso en odontología / Laser Doppler and its use in dentistry

El efecto Doppler es la base científica de la flujometría láser Doppler. El efecto fue descrito por primera vez en el año de 1842 por el físico austriaco Christian Doppler en su tratado Über das farbige licht der doppelsterne und einige andere gestirne des himmels (Sobre el color de la luz en estrellas binarias y otros astros). Este principio ha permitido desarrollar técnicas y aparatos que han sido empleados en el ramo médico para medir la perfusión en diversos órganos y tejidos del cuerpo, y que han sido útiles como método diagnóstico. En la odontología, poco a poco comienza a reportarse información acerca del uso del Doppler en las diversas estructuras bucodentales, y ha demostrado ser no invasivo y de gran utilidad diagnóstica. Son pocos los estudios reportados en la rama de la odontología en cuanto a esta nueva tecnología; es importante comenzar líneas de investigación apoyadas en ella para beneficio de los pacientes.

The Doppler eff ect, the scientifi c basis of laser Doppler fl owmetry, wasfi rst described in 1842 by Austrian physicist Christian Doppler in histreatise Über das farbige Licht der doppelsterne und einige andere gestirnedes Himmels (On the Colored Light of the Binary Stars and SomeOther Stars of the Heavens). This principle has led to the developmentof techniques and devices that have been used in the fi eld of medicineto measure perfusion in various organs and tissues, and have provideda useful method of diagnosis. In dentistry, information on the use ofthis method in the various structures of the mouth has slowly begunto be published. As a result, the need for its continued use in the fi eldof oral health has become evident, given that it has proven to be noninvasiveand extremely useful in diagnosis. It is a diagnostic technique that is commonly used in healthcare and has been widely developedin the fi eld of medicine, yet there have been few reported studies of it suse in dentistry, which is an important step towards opening new linesof research based on this new technology for the benefi t of patients.

Avaliação da fluxometria laser doppler na região geniana em pacientes sob terapia antineoplásica / Laser doppler flowmetry evaluation in the genius region in patients undergoing antineoplastic therapy

A quimioterapia e a radioterapia são modalidades terapêuticas não cirúrgicas aplicadas a pacientes com neoplasias malignas. A mucosite oral (MO) é uma inflamação da mucosa oral decorrente destas terapias antineoplásicas, manifestando-se por atrofia, inchaço, eritema e úlcera, comprometendo a qualidade de vida. A patogênese da mucosite oral envolve uma cascata de eventos de natureza inflamatória que culminam em alterações no epitélio e no tecido conjuntivo. Dentre estas modificações destacam-se as alterações na microvascularização, as quais precedem as alterações epiteliais na mucosa oral induzida por radiação e pelos agentes quimioterápicos. A Fluxometria Laser Doppler é um método não invasivo que permite avaliar parâmetros clínicos da microcirculação através do monitoramento do fluxo continuamente, em tempo real. O objetivo deste estudo foi avaliar a fluxo sanguíneo na região geniana em pacientes sob radioterapia de cabeça e pescoço ou quimioterapia através da técnica de Fluxometria Laser Doppler e comparar a graduação de mucosite oral e dor com dados obtidos na avaliação do fluxo sanguíneo. Este estudo observacional e prospectivo teve uma amostra de 14 pacientes oncológicos que foram avaliados antes do início da terapia antineoplásica e durante a fase intensiva da radioterapia de cabeça e pescoço ou quimioterapia, em 7 momentos. Para esta avaliação foi utilizado o Fluxômetro Laser Doppler para o registro do fluxo sanguíneo; as escalas da OMS (Organização Mundial da Saúde) e OMAS (Oral Mucositis Assessment Scale) para a avaliação do grau de mucosite; e Escala Visual Analógica (EVA) para a avaliação da dor em mucosa oral. Ao se comparar o fluxo sanguíneo nos tempos T1, T2, T3, T4, T5 e T6 com o T0, para os pacientes submetidos a radioterapia de cabeça e pescoço, não houve diferença estatística (p>0,05). Para os pacientes sob quimioterapia, houve diferença estatística nos tempo T1 (p=0,033) e T6 (p=0,043). Houve correlação positiva fraca entre as escalas para avaliação de mucosite oral (OMS (p=0,031) e OMAS (p=0,009)) e o fluxo sanguíneo. Não houve grau de relação entre dor induzida por mucosite oral e fluxo sanguíneo (p>0,05). A Fluxometria Laser Doppler permitiu a observação da dinâmica microvascular da região geniana da face em pacientes sob terapia antineoplásica e com risco de desenvolvimento de mucosite oral. Nos pacientes sob quimioterapia, houve aumento de perfusão cutânea na face nos tempos iniciais da MO, com progressiva redução do fluxo no decorrer do ciclo de quimioterapia.(AU)

Chemotherapy and radiotherapy are non surgical therapeutic modalities to malignancies. Oral mucositis is a inflammation of the oral mucosa due to these cancer therapy, typically manifesting as atrophy, swelling, erythema and ulceration compromising the quality of life. The pathogenesis of oral mucositis (OM) involves a cascade of inflammation events that result in changes in the epithelial layer and connective tissue, including microvascular modifications. These modifications precede epithelial changes induced by radiation therapy and chemotherapeutic agents, thereby modifications in blood flow may be a predictive factor of the severity of oral mucositis. Laser Doppler flowmetry (LDF) is a non invasive method enabling the monitoring of microvascular blood flow continuously in real time. The aim of this study was to evaluate the blood flow in the genius region in patients undergoing head and neck radiation and/or chemotherapy by Laser Doppler Flowmetry and compare the degree of oral mucositis and pain with data obtained in the evaluation of blood flow. This prospective observational study had a sample of 14 oncologic patients who were evaluated before and during the intensive phase of head and neck radiotherapy or chemotherapy in 7 times. For this evaluation, we used the Laser Doppler Flowmeter to measure blood flow; WHO scale (World Health Organization) and OMAS (Oral Mucositis Assessment Scale) for assessing the severity of mucositis; and Visual Analogue Scale (VAS) for pain assessment in oral mucosa. When we compare blood flow in T1, T2, T3,T4, T5 and T6 with T0, for patients undergoing radiotherapy for head and neck, there was no statistical difference (p> 0.05). For patients undergoing chemotherapy, there was a statistical difference in time T1 (p = 0.033) and T6 (p = 0.043). There was a weak positive correlation between the scale for assessing oral mucositis (WHO (p = 0.031) and OMAS (p = 0.009)) and blood flow. There was no relation degree pain induced oral mucositis and blood flow (p>0.05). Laser Doppler flowmetry allowed the observation of microvascular dynamics in the genian region of the face in patients undergoing antineoplastic therapy and risk of developing mucositis. In patients undergoing chemotherapy, there was an increase of skin perfusion in the face in the early days of the OM, with progressive reduction in flow during the course of chemotherapy.(AU)

Cell phone radiation effects on cytogenetic abnormalities of oral mucosal cells

The aim of this study was to evaluate the effects of exposure to cell phone electromagnetic radiation on the frequency of micronuclei, broken eggs cells, binucleated cells, and karyorrhexis in epithelial cells of the oral mucosa. The sample was composed of 60 cell phone users, who were non-smokers and non-drinkers, and had no clinically visible oral lesions. Cells were obtained from anatomical sites with the highest incidence of oral cancer: lower lip, border of the tongue, and floor of the mouth. The Feulgen reaction was used for quantification of nuclear anomalies in 1,000 cells/slide. A slightly increase in the number of micronucleated cells in the lower lip and in binucleated cells on the floor of the mouth was observed in individuals who used their phones > 60 minutes/week. The analysis also revealed an increased number of broken eggs in the tongue of individuals owning a cell phone for over eight years. Results suggest that exposure to electromagnetic waves emitted by cell phones can increase nuclear abnormalities in individuals who use a cell phone for more than 60 minutes per week and for over eight years. Based on the present findings, we suggest that exposure to electromagnetic radiation emitted by cell phones may interfere with the development of metanuclear anomalies. Therefore, it is demonstrated that, despite a significant increase in these anomalies, the radiation emitted by cell phones among frequent users is within acceptable physiological limits.

Avaliação da eficácia clínica do uso de laser de baixa potência, vitamina E (alfa-tocoferol) e protocolo farmacológico no manejo da mucosite oral radioinduzida / Evaluation of clinical effectiveness of low-level laser, vitamin E (tocopherol-alpha) and pharmcological protocol on oral mucosistis radiation induced handling

A mucosite oral é o efeito colateral agudo mais importante decorrente do tratamento radioterápico em região de cabeça e pescoço. O objetivo do presente estudo foi avaliar a eficácia clínica do laser de baixa potência, da Vitamina E (alfa-tocoferol) e do protocolo farmacológico (nistatina, tetraciclina, hidrocortisona e vitamina E) como formas de tratamento para a mucosite oral em graus 2 e 3. Este estudo consiste em um ensaio clínico randomizado realizado com 41 pacientes tratados no período de Setembro de 2010 a Janeiro de 2012 e divididos em três grupos de tratamento, sendo: A- laserterapia de baixa potência; B- bochechos com Vitamina E; e C- bochechos com o protocolo farmacológico. A mucosite oral foi avaliada de acordo com os critérios da Organização Mundial de Saúde (OMS) e a avaliação de sintomas subjetivos como xerostomia, alteração no fluxo salivar, paladar, olfato, movimentação muscular e dor foi realizada através da escala visual analógica. Após os tratamentos, não houve redução significativa em relação ao grau da mucosite (P=0,34), porém, os pacientes que realizaram o tratamento com o laser de baixa potência apresentaram menor severidade no grau da mucosite quando comparado aos outros grupos, enquanto os pacientes que utilizaram bochechos com Vitamina E não demonstraram redução no grau da mucosite (P=0,05). Quanto aos sintomas relatados pelo paciente, os tratamentos realizados com laser de baixa potência e protocolo farmacológico, auxiliaram de forma significativa na redução da intensidade da dor, porém a laserterapia, se mostrou mais eficaz durante todo o período do tratamento, apresentando maior redução da dor nos pacientes irradiados em região de cabeça e pescoço. Portanto neste estudo, não houve tratamento mais eficaz para o manejo da mucosite oral, embora o laser de baixa potência tenha diminuído a severidade do grau da mucosite em relação aos outros tratamentos

Oral adverse effects of head and neck radiotherapy: literature review and suggestion of a clinical oral care guideline for irradiated patients

Radiotherapy, alone or associated with surgery or chemotherapy, produces a significant increase in cure rates for many malignancies of the head and neck region. However, high doses of radiation in large areas, including the oral mucosa, may result in several undesired reactions that manifest during or after the completion of therapy. The multidisciplinary management is the best alternative to minimize or even prevent such reactions, and the dentist has a fundamental role in this context. This paper reviews the literature related to the main oral sequelae from head and neck radiotherapy and establishes clinical oral management protocol for these irradiated patients.

Laser phototherapy as a treatment for radiotherapy-induced oral mucositis

Oral mucositis is a harmful side effect of radiotherapy (RT) on the head and neck region. There are encouraging reports on the beneficial aspects of the use of laser light on the treatment of oral mucositis. This paper reports the efficacy of laser phototherapy (LPT) on the treatment of oral mucositis in a patient undergoing RT after surgical removal of a squamous cell carcinoma with osseous invasion of the maxilla. Palatal and commissural lesions were treated with λ660 nm, 40 mW, ∅=4 mm², in contact mode, 5 x 2.4 J/cm² per point, 14.4 J/cm² per session. For treating the lesion on the patient's nasal mucosa, LPT (∅=4 mm², λ780 nm, 70 mW, 3 x 2.1 J/cm² per point, 6.3 J/cm² per session, contact mode) was used on the external area of the nose. A single dose (2.4 J/cm²) with the λ660 nm laser, as described before, was applied on the entrance of each nostril. LPT was used 3 times/week during 4 weeks. Treatment results indicate that the use of LPT on oral mucositis was effective and allowed the patient to carry on the RT without interruption. However, long-term and controlled clinical trials are necessary to establish both preventive and curative protocols using LPT.

A mucosite oral é um efeito colateral prejudicial da radioterapia na região de cabeça e pescoço. Existem estudos que evidenciam o efeito benéfico do uso da luz laser no tratamento da mucosite oral. O objetivo deste caso clínico foi o de avaliar a eficácia da fototerapia laser no tratamento da mucosite oral em um paciente sendo submetido a radioterapia, após a remoção cirúrgica de um carcinoma escamocelular, com invasão óssea da maxila. As lesões do palato e das comissuras labiais foram tratadas com λ660 nm, 40 mW, ∅=4 mm², em contato, 5 x 2.4 J/cm² por ponto, 14.4 J/cm² por sessão. Na lesão existente na mucosa nasal a fototerapia laser (∅=4 mm², λ780 nm, 70 mW, 3 x 2.1 J/cm² por ponto, 6.3 J/cm² por sessão, em contato) foi utilizada na área externa do nariz. Uma dose única (2.4 J/cm²) com o laser λ660 nm e os parâmetros descritos anteriormente foi aplicado na entrada de cada narina. A fototerapia laser foi utilizada 3 vezes por semana, durante 4 semanas. Os resultados do tratamento são indicativos de que o uso da fototerapia laser em mucosite oral foi efetiva e permitiu ao paciente continuar o tratamento radioterápico sem interrupções. Entretanto, estudos clínicos controlados são necessários para se estabelecer os protocolos, para tratamento e prevenção da mucosite oral, utilizando fototerapia laser.

Single exposure of human oral mucosa fibroblasts to ultraviolet B radiation reduces proliferation and induces COX-2 expression and activation

The lip vermillion constitutes a transition tissue, between oral mucosa and skin, where oral mucosal cells from epithelial and connective tissue compartments are exposed to ultraviolet (UV) sunlight. Fibroblasts are abundant resident cells of the connective tissue which are key regulators of extracellular matrix composition, as well as, epithelial and endothelial cell function. UVB light, an inherent component of sunlight, causes several alterations in skin fibroblasts, including premature senescence and increased cyclooxygenase (COX)-2 expression. To assess if UVB irradiation had similar effects on fibroblasts derived from human oral mucosa (HOM), primary cultures of HOM fibroblasts were irradiated with a single dose of 30 or 60 mJ/cm²of UVB light or sham-irradiated. Fibroblast proliferation was assessed from 3 to 48 hrs after UVB-irradiation utilizing [³H]-thymidine incorporation and MTT assays. In addition, COX-2 mRNA expression was detected by RT-PCR, and PGE2 production was assessed using enzyme immunoassay from 0.5 to 24 hrs after UVB-irradiation. The results showed a significant decrease in proliferation of UVB-irradiated HOM fibroblasts as compared to controls as measured by both [³H]-thymidine incorporation and MTT assays (p<0.001). HOM fibroblasts had increased COX-2 mRNA expression at 0.5 and 12 hrs after irradiation, and PGE2 production was elevated at 12 and 24 hrs post-irradiation as compared to controls (p<0.05). The results showed an inhibitory effect of a single dose of UVB irradiation on HOM fibroblast proliferation with an increase in COX-2 expression and activation. Therefore, photodamaged fibroblasts may play and important role in the pathogenesis of UV-induced lesions of the lip.

Criterios de evaluación odontológica pre-radioterapia y necesidad de tratamiento de las enfermedades orales post-radioterapia en cabeza y cuello / Pre-radiotherapy dental evaluation criteria and treatment needs of oral side effects after head and neck radiotherapy

El objetivo de esta revisión es presentar criterios de evaluación odontológica pre-radioterapia y cuáles son las principales necesidades de tratamiento de estos pacientes después del tratamiento de radiación. Fueron revisados artículos en inglés, español y portugués entre 1995 y 2009 indexados en Pubmed y Scielo. Las palabras claves fueron: cáncer oral y radioterapia, complicaciones de la radioterapia en cabeza y cuello, evaluación oral pre-radioterapia. Los efectos colaterales de la radioterapia en la región de cabeza y cuello pueden ser temporales o tardíos. Aquellos que son tardíos, como la caries de radiación y la osteorradionecrosis pueden estar directamente relacionados con el hecho de no haber realizado una evaluación odontológica previa y pueden afectar severamente la calidad de vida del paciente.La participación del cirujano-dentista en el equipo multidisciplinario y la evaluación odontológica de los pacientes que serán sometidos a radioterapia en la región de cabeza y cuello son de vital importancia en mejorar la calidad de vida post-operatoria de estos pacientes.

The objective of this review is to present pre-radiotherapy evaluation criteria and the main needs for treatment of these patients after the radiation therapy. Were revised articles in English, Spanish and Portuguese language between 1995 and 2009 indexed in Pubmed and Scielo. The keywords were oral cancer and radiotherapy, complications in head and neck radiotherapy, oral pre-radiotherapy evaluation.The adverse complications of radiotherapy in head and neck area could be temporary or late. The late effects, such as radiation caries and osteorradionecrosis could be directly associated with the fact that previous dental evaluation was not performed and can severely affect the post-operatory quality of life. The participation of the dentist in the multidisciplinary team and dental evaluation of the patients that will receive radiotherapy in the head and neck area are of vital importance to improve the post-operatory quality of life of these patients.