Investigation of mast cells in human gingiva following low-intensity laser irradiation.

OBJECTIVE: The aims of the present study were to investigate the effect of low-intensity laser irradiation on the total number of mast cells as well as the percentage of degranulation in human gingiva. Blood vessel dilation was also evaluated. BACKGROUND DATA: It has been proposed that low-intensity laser irradiation can ameliorate pain, swelling, and inflammation. In periodontal tissue, mast cells may influence either the destructive events or the defense mechanism against periodontal disease via secretion of cytokines and through cellular migration to improve the healing process. Mast cells play an important role in the inflammatory process. METHODS: Twenty patients with gingival enlargement indicated for gingivectomy were selected. Gingival fragments were obtained from each patient and divided into three different groups before surgery. One fragment was removed without any irradiation. The two others were submitted to punctual irradiation with an energy density of 8 J/cm(2) at an output power of 50 mW at 36 Hz for 36 sec before gingivectomy. Nondegranulated and degranulated mast cells were counted in five areas of the gingival fragment connective tissue. Major and minor diameters of the blood vessels were also measured. RESULTS: Both red and infrared radiation promoted a significant increase in mast cell degranulation compared to controls; however, no statistically significant differences (p > 0.05) were observed between the irradiated groups. No significant differences among the groups were observed regarding blood vessel size. CONCLUSION: The results suggests that red and infrared wavelengths promote mast cell degranulation in human gingival tissue, although no dilation of blood vessels was observed. The effects of premature degranulation of mast cells in human tissue and the laser radiation protocol applied in this study encourage further investigations to extend these results into clinical practice.

Development of an open case-based decision-support system for diagnosis in oral pathology.

BACKGROUND: Making diagnoses in oral pathology are often difficult and confusing in dental practice, especially for the less-experienced dental student. One of the most promising areas in bioinformatics is computer-aided diagnosis, where a computer system is capable of imitating human reasoning ability and provides diagnoses with an accuracy approaching that of expert professionals. This type of system could be an alternative tool for assisting dental students to overcome the difficulties of the oral pathology learning process. This could allow students to define variables and information, important to improving the decision-making performance. However, no current open data management system has been integrated with an artificial intelligence system in a user-friendly environment. Such a system could also be used as an education tool to help students perform diagnoses. The aim of the present study was to develop and test an open case-based decision-support system. METHODS: An open decision-support system based on Bayes' theorem connected to a relational database was developed using the C++ programming language. The software was tested in the computerisation of a surgical pathology service and in simulating the diagnosis of 43 known cases of oral bone disease. The simulation was performed after the system was initially filled with data from 401 cases of oral bone disease. RESULTS: The system allowed the authors to construct and to manage a pathology database, and to simulate diagnoses using the variables from the database. CONCLUSION: Combining a relational database and an open decision-support system in the same user-friendly environment proved effective in simulating diagnoses based on information from an updated database.

[Comparative study of intestinal anastomosis with manual suture and biofragmentable ring in dogs under corticosteroid administration]. / Estudo comparativo entre anastomoses intestinais com sutura manual e com anel biofragmentável em cães sob a administração de corticosteróides.

BACKGROUND: This study analyzed intestinal anastomoses by manual suture and by compression with biofragmentable ring under delay of cicatrization administering parenteral corticoids. MATERIAL AND METHODS: Twenty dogs were divided into two groups: control and test, the latter submitted to intramuscular administration of hydrocortisone hemisuccinate, 25 to 33 mg/kg/day, on the 30th preoperative and 7th postoperative days. During surgery, each animal underwent two colon sections with anastomosis by manual suture in a single extramucous plane and compression with biofragmentable ring. The animals were sacrificed 7 days after the procedure to evaluate the anastomoses. RESULTS: In the postoperative period, one death occurred in the test group and two in the control group, caused by nonblocked fistula in the anastomoses by ring compression. Statistically, there was a similar incidence of adherences, fistulas, afferent dilatation and obstruction using comparison methods. On microscopy, deficiency in mucous regeneration of the anastomoses by compression was observed. Computerized histological analysis evidenced in the anastomoses by compression, a greater inflammatory reaction, greater edema of the submucous membrane and enlarged scars. CONCLUSIONS: It was concluded that, with the biofragmentable ring, in colonic anastomosis under delay of cicatrization induced by corticoids, similar results to manual suture regarding to postoperative complications incidence were obtained; ring, however, determined worse mucous regeneration and greater cicatricial inflammatory reaction.

Estudo comparativo entre anastomoses intestinais com sutura manual e com anel biofragmentável em cäes sob a administraçäo de corticosteróides / Comparative study between intestinal anastomosis with manual suture and biofragmentable ring in dogs under corticosteroid administration

OBJETIVO: Este estudo analisou anastomoses intestinais por sutura manual e por compressão com anel biofragmentável, sob retardo cicatricial pela administração parenteral de corticosteróides. MATERIAL E MÉTODOS: Vinte cães, entre 15 e 20 kg, foram divididos em grupos controle e teste, este submetido à administração intramuscular de hemissuccinato de hidrocortisona, de 25 a 33 mg/kg/dia, do 30§ dia pré-operatório ao 7§ dia pós-operatório. Em ato cirúrgico, cada animal foi submetido a duas secções cólicas, com anastomoses por sutura manual em plano único extramucoso e por compressão com anel biofragmentável. Os espécimes foram sacrificados sete dias após o procedimento para avaliação das anastomoses. RESULTADOS: No pós-operatório ocorreram um óbito no grupo teste e dois óbitos no grupo controle por fístula não bloqueada nas anastomoses por compressão com anel. Houve, estatisticamente, incidência semelhante de aderências, fístulas, dilatação aferente e obstrução, nos métodos em comparação. À microscopia, houve deficiência de regeneração mucosa nas anastomoses por compressão. Análise histológica por computador evidenciou nas anastomoses por compressão, maior reação inflamatória, maior edema de submucosa e formação de cicatrizes alargadas. CONCLUSÕES: Com o anel biofragmentável, em anastomoses colocólicas sob retardo de cicatrização induzido por corticosteróides, foram obtidos resultados semelhantes aos da sutura manual quanto à incidência de complicações pós-operatórias; o anel, entretanto, determinou pior regeneração mucosa e maior reação inflamatória cicatricial.

Thickness of the remaining enamel after the preparation of cingulum rest seats on maxillary canines.

PURPOSE: This study evaluated the level of tissue removal that takes place on enamel and dentin during cingulum rest seat preparation. MATERIAL AND METHODS: A quantitative evaluation of the thickness of the remaining enamel of cingulum seat preparations to receive removable partial denture rests was carried out in 20 maxillary canines with a light optical microscope. RESULTS: Thirty percent of the preparations were overextended into dentinal tissue, and 85% had depths that were insufficient to receive rests.

Aplicaçäo do processamento de imagens por computador na quantificaçäo das variáveis histopatológicas da reparaçäo tecidual de anastomoses colocólicas em cäes / Computer-assisted image processing for quantifying histopathologic variables in the healing of colonic anastomosis in dogs

Objetivo. Os autores apresentam a metodologia de quantificaçäo, através do processamento de imagens, de estruturas teciduais microscópicas envolvidas no processo de reparaçäo de anastomoses colocólicas, feitas por meio de sutura manual e por anel biofragmentável. As variáveis quantificadas neste trabalho foram líquido de edema, tecido fibromuscular, vasos e núcleos celulares. Material e Métodos. Para esta análise, foi utilizado programa de processamento de imagens desenvolvido no Laboratório de Informática Dedicado à Odontologia (LIDO) da Universidade de Säo Paulo, com a finalidade de quantificar as alteraçöes patognomônicas do processo inflamatório em anastomoses colocólicas em 14 cäes. Os resultados foram comparados, como contraprova, aos obtidos através de leitura convencionais feitas por dois patologistas. A gradaçäo de alteraçöes ausentes, leves, moderadas e intensas foi utilizada nesta leitura para que se semiquantificassem as mesmas variáveis lidas pelo computador. Resultados. Houve diferença significativa entre as duas técnicas, com a de anel biofragmentável apresentando menor quantidade de edema, fibras organizadas e prevalência de núcleos celulares alongados em relaçäo aos esféricos, sinal evidente de organizaçäo tecidual. Conclusäo. Os resultados permitiram concluir que a histometria por processamente de imagem computacional mostrou-se eficiente na quantificaçäo das principais estruturas teciduais envolvidas no processo inflamatório e reparativo.

[Computer-assisted image processing for quantifying histopathologic variables in the healing of colonic anastomosis in dogs]. / Aplicação do processamento de imagens por computador na quantificação des variáveis histopathológicas de reparação tecidual de anastomoses colocólicas em cães.

BACKGROUND: The authors present the experimental results of the computerized quantifying of tissular structures involved in the reparative process of colonic anastomosis performed by manual suture and biofragmentable ring. The quantified variables in this study were: oedema fluid, myofiber tissue, blood vessel and cellular nuclei. MATERIAL AND METHODS: An image processing software developed at Laboratório de Informática Dedicado à Odontologia (LIDO) was utilized to quantifying the pathognomonic alterations in the inflammatory process in colonic anastomosis performed in 14 dogs. The results were compared to those obtained through traditional way diagnosis by two pathologists in view of counterproof measures. The criteria for these diagnoses were defined in levels represented by absent, light, moderate and intensive which were compared to analysis performed by the computer. RESULTS: There was significant statistical difference between two techniques: the biofragmentable ring technique exhibited low oedema fluid, organized myofiber tissue and higher number of alongated cellular nuclei in relation to manual suture technique. CONCLUSION: The analysis of histometric variables through computational image processing was considered efficient and powerful to quantify the main tissular inflammatory and reparative changing.

Effects of unilateral upper incisor extraction on facial growth of young rats.

The effects of unilateral extraction of the upper incisor (one tooth) on facial growth of young rats were studied. The remaining upper incisor showed deviation towards the opposite side, and there was regular dental wear of all the incisors. The effects were evident only in the mid-facial area. Cephalometric measurements showed significant shortening with deviation of the incisor bone on the extraction side. There was no significant disturbance of the growth of the rest of the maxilla and mandible. These results indicate that upper incisor extractions have a localized influence, leading to impairment of incisor bone growth.

Estudo experimental comparativo entre anastomose colocólica com sutura manual e com anel biofragmentável / Comparative experimental study between colocolic anastomosis with manual suture and biofragmentable ring

OBJETIVO. Os autores realizaram um estudo experimental comparando anastomoses colocólicas realizadas através de sutura manual seromuscular, pontos separados de fio sintético absorvível monofilamentar de poligliconato,com anel anastomótico biofragmentável; este dispositivo, constituído por ácido poliglicólico (87,5//) e sulfato de bário (12,5//), determina cicatrizaçäo dos cotos cólicos por aposiçäo sero-serosa, sendo eliminado através da evacuaçäo, em virtude de sua fragmentaçäo por hidrólise, duas a três semanas após sua implantaçäo. MATERIAL E MÉTODOS. Foram operados 14 cäes, estudando-se 28 anastomoses, 14 com a sutura manual clássica e 14 com o anel biofragmentável, ambas no mesmo segmento cólico e em seqüência alternada, distantes entre si 10cm. Foram comparados o tempo de execuçäo, dificuldades técnicas, evoluçäo clínica e a qualidade da cicatrizaçäo. O exame histopatológico foi realizado por meio de metodologia convencional clássica e também utilizando-se programaçäo específica de processamento de imagens por computador, com a finalidade de quantificar as alteraçöes observadas. RESULTADOS. Todos os cäes apresentaram boa evoluçäo clínica. Após período médio de 33 dias os cäes foram reoperados, constatando-se maior incidência de aderências perianastomóticas na sutura manual. Os índices anastomóticos foram semelhantes em ambos os métodos, observando-se, no entanto, infiltrado inflamatório com reaçäo granulomatosa de corpo estranho, fibrose e espessamento da parede intestinal mais acentuados em todas as anastomoses com sutura. A quantificaçäo do líquido de edema na anastomose, mediante recurso da informática, mostrou diferença signficantemente maior na sutura manual do que no anel biofragmentável. CONCLUSAO. Os autores concluem, baseados nos resultados obtidos, que a utilizaçäo do anel anastomótico biofragmentável representa uma alternativa segura, mais uniforme, fácil e mais rápida para a execuçäo de anastomoses colocólicas, determinando cicatrizaçäo com menor reaçäo inflamatória. Näo foram observadas diferenças quanto à incidência de complicaçöes no pós-operatório

[Comparative experimental study of colocolic anastomosis with manual suture and biofragmentable ring]. / Estudo experimental comparativo entre anastomose colocólica com sutura manual e com anel biofragmentável.

BACKGROUND: The authors undertook an experimental trial, in order to compare one layer interrupted sutured large bowel anastomosis with that of biofragmentable anastomotic ring (BAR). This device creates an inverted serosa-to-serosa anastomosis. It is designed to fragment after hydrolysis and it is passed within the faeces after healing of the anastomosis. Fourteen dogs were operated on, having been performed 28 anastomoses, 14 with conventional way and 14 with the BAR, both in the same bowel, on alternate sequence and 10cm from each other. MATERIAL AND METHODS: Performing time, technical difficulties, postoperative complications and the healing anastomotic quality were studied. Histological examination was done not only by traditional technique but also by using computerized program, in order to measure the amount of inflammatory infiltration at the anastomosis site. RESULTS: All dogs tolerated the operation well and postoperative period was uneventful. At laparotomy, after an average time of 33 days, perianastomotic adherence was mostly noted in the sutured anastomosis. Anastomotic index had no significant difference in both methods, but inflammatory change was mostly detected in sutured anastomosis, on which the amount of edema infiltration was significantly higher. CONCLUSIONS: Based on these results, the authors conclude that the BAR anastomosis appears to be a safe alternative, uniform, more rapid and easy technique, with better healing. No difference in the clinical results was noted.

[Student evaluation of some aspects of the general pathology course at the University of São Paulo Dental School]. / Avaliaçao por alunos de alguns aspectos do curso de patologia geral da Faculdade de Odontologia da Universidade de São Paulo.

An inquiry based on questionnaires about some aspects of the general pathology course offered to the students of the FOUSP during the last three years was realized. It has been demonstrated that the most important chapters were inflammation and repair, due to its usefulness on the other courses of the curriculum. The macroscopy and microscopy lessons doesn't seem to contribute with relevance on the apprenticeship of the subject matter, in accordance to the students' opinion. So, it seems that, a good classical lecture for these scholars, is still the better way to teach.

Estudo clinico e histologico comparativo, em gengiva humana, da tecnica de sutura continua com duas agulhas em alca, com a tecnica de sutura interrompida interproximal. / Clinical and histological comparative study in human gingiva of the continuos suturing technic with two needles in loop with the interrupted interproximal suturing technic

Um estudo comparativo em gengiva humana foi realizado utilizando duas tecnicas de sutura: uma classica interrompida interproximal e outra continua com duas agulhas em alca. As diferencas clinicas observadas baseiam-se na melhor adaptacao obtida com o retalho e nas melhores condicoes de trabalho determinadas pela maior rapidez e maior facilidade na remocao do cimento cirurgico conseguidas com a tecnica de sutura continua. A analise da saude gengival no periodo de tres meses, alem de outros aspectos clinicos estudados nao puderam demonstrar diferencas apreciaveis existentes entre estas duas tecnicas. Os resultados histologicos demonstraram um mesmo padrao de reparacao, se bem que maturacao tecidual mais precoce e menor grau de inflamacao foram observados no lado em que utilizamos a tecnica continua com duas agulhas