Efficiency of mixed and rigid occlusal stabilization splints: Randomized clinical trial

Abstract Occlusal stabilization splints are the most common treatment for controlling the deleterious effects of sleep bruxism. This study aimed to evaluate the effectiveness of a low-cost, mixed occlusal splint (MOS) compared to that of a rigid splint. A randomized clinical trial was performed on 43 adults of both sexes with possible sleep bruxism and satisfactory dental conditions. They were divided into rigid occlusal splint (ROS) (n = 23) and MOS (n = 20) groups. Masticatory muscle and temporomandibular joint (TMJ) pain intensity (visual analog scale), quality of life (WHOQOL-BREF), indentations in the oral mucosa, anxiety, and depression (HADS), number of days of splint use, and splint wear were evaluated. All variables were evaluated at baseline (T0), 6 months (T6), and 12 months (T12) after splint installation (T0), and splint wear was evaluated at T6 and T12. Student's t-test, Mann-Whitney U test, non-parametric Friedman's analysis of variance for paired samples and pairwise multiple comparisons, Pearson's chi-square test, two-proportion z-test, non-parametric McNemar's and Cochran's Q, and Wilcoxon tests were used (p < 0.05). In both groups, there was a decrease in TMJ pain and pain intensity over time and improvements in the quality of life scores. At T6, there was a higher rate of splint wear in the MOS group than in the ROS group (p = 0.023). The MOS showed a higher rate of wear than the rigid splint but had similar results for the other variables. Therefore, the use of a mixed splint appears to be effective in controlling the signs and symptoms of sleep bruxism.

The influence of fluoxetine on orthodontic tooth movement in rats

Abstract This study aimed to evaluate the effects of chronic use of fluoxetine on the amount of orthodontic tooth movement and tissue changes in rats. A total of 192 Wistar rats were divided into 4 groups: S, 0.9% saline solution; F, 20 mg/kg of fluoxetine; SM, 0.9% saline solution with orthodontic movement; and FM, 20 mg/kg of fluoxetine with orthodontic movement. After 30 days of daily saline or fluoxetine administration, an orthodontic device (25cN) was used to mesially displace the first molar in animals of the groups SM and FM. The animals were euthanized 2, 7, 14, and 28 days after placement of the orthodontic appliances and animals of groups S and F were euthanized at the same time. The assessment of tooth movement was made in gypsum castings, the collagen neoformation was assessed by polarization microscopy, the number of osteoclasts and root resorption were evaluated using tartrate-resistant acid phosphatase, and presence of hyalinized areas was assessed by hematoxylin-eosin staining. Fluoxetine did not affect the amount of tooth displacement, percentage of collagen, number of osteoclasts, and presence of hyalinized areas (P>0.05). There was a higher frequency of root resorption areas in the FM group than in the SM group only on the second day (P<0.05). The findings of this study show that chronic use of 20 mg/kg fluoxetine does not affect the amount of tooth movement, collagen neoformation, number of osteoclasts, or hyalinized areas and does not affect root resorption until the last day of orthodontic movement.

Effect of acute administration of nicotine and ethanol on tooth movement in rats

Abstract The aim of this study was to evaluate the effect of acute administration of nicotine and ethanol on tooth movement in rats. Two hundred rats were divided into eight groups: S: saline; N: nicotine; E: ethanol; NE: nicotine and ethanol; SM: saline with tooth movement; NM: nicotine with tooth movement; EM: ethanol with tooth movement; and NEM: nicotine and ethanol with tooth movement. All the solutions were applied for 32, 44, or 58 days, according to the subgroup. Orthodontic movement (25 cN) was initiated 30 days after solution administration in the groups with tooth movement. The rats were euthanized 2, 14, or 28 days after initiation of tooth movement. Tooth sections were stained using picrosirius and tartrate-resistant acid phosphatase (TRAP). The data were compared by ANOVA using Tukey's HSD and Games-Howell. On day 28 of tooth movement, the NEM group had a lower percentage of type I collagen compared to the SM group (p = 0.0448), and the S group had a higher number of osteoclasts/μm2 compared to the N group (p = 0.0405). Nicotine and ethanol did not affect the tooth movement rate, regardless of induction of orthodontic movement. Nicotine influenced the number of osteoclasts by decreasing their quantity when dental movement was not induced. When nicotine was associated with ethanol, it interfered in the maturation of collagen fibers during orthodontic movement.

Interaction of Anabolic Androgenic Steroids and Induced Tooth Movement in Rats

Abstract This study evaluated the interaction between tooth movement and two anabolic androgenic steroids (AAS), Deposteron® and Nebido®. One hundred Wistar rats were divided into 3 groups: control (C) n=30, Nebido experimental (N) n=35 and Deposteron experimental (D) n=35. The control group was subdivided into 6 subgroups: 1, 2, 3, 5, 7 and 14. The experimental groups were subdivided into 7 subgroups: 0, 1, 2, 3, 5, 7 and 14, which corresponded to the day of animal's euthanasia after applying orthodontic force. Orthodontic devices were used to induce tooth movement using 50 cN of reciprocal force between the maxillary right first molar and the maxillary incisors. After euthanasia, the tissues were processed and stained with hematoxylin and eosin (HE) and tartrate-resistant acid phosphatase (TRAP). Osteoclasts, Howship's lacunae and blood vessels were quantified. Groups N and D showed acceleration in the reorganization of the periodontal ligament compared to group C. The peak of the histological events occurred in group C on day 5 and in groups N and D on day 3 after installation of the orthodontic device. There was a statistically significant difference in the number of osteoclasts (p<0.05) between groups N3 and C3, and between groups N3 and D3. Supra-physiological doses of the AAS Nebido® and Deposteron® altered the number of osteoclasts, Howship's lacunae and blood vessels, accelerating the reorganization of the periodontal ligament, resulting in accelerated biological effects from the induced tooth movement in rats.

Resumo Este estudo avaliou a interação do movimento dentário entre dois esteróides anabólicos androgênicos (EAA), Deposteron® and Nebido®. Cem ratos Wistar foram divididos em 3 grupos: controle (C) n=30, Nebido experimental (N) n=35 e Deposteron experimental (D) n=35. O grupo controle foi subdivido em 6 subgrupos: 1, 2, 3, 5, 7 e 14. Os grupos experimentais foram subdivididos em 7 subgrupos: 0, 1, 2, 3, 5, 7 e 14, correspondendo ao dia da eutanásia do animal após aplicada a força ortodôntica. Um dispositivo ortodôntico foi utilizado para induzir a movimentação dentária com força recíproca de 50 cN entre o primeiro molar superior direito e os incisivos superiores. Após a eutanásia, o tecido foi processado e corado com hematoxilina e eosina (HE) e fosfatase ácida tartarato-resistente (TRAP). Osteoclastos, lacunas de Howship e vasos sanguíneos foram quantificados. Os grupos N e D demonstraram aceleração na reorganização do ligamento periodontal comparado ao grupo C. O pico dos eventos histológicos ocorreu no grupo C no dia 5 e nos grupos N e D no dia 3, após a instalação do dispositivo ortodôntico. Houve diferença estatisticamente significante no número de osteoclastos (p<0,05) entre os grupos N3 e C3 e entre os grupos N3 e D3. Doses supra-fisiológicas de EAA Nebido® and Deposteron® alteraram o número de osteoclastos, lacunas de Howship e vasos sanguíneos, acelerando a reorganização do ligamento periodontal, resultando na aceleração dos efeitos biológicos na movimentação dentária em ratos.

Effects of Zoledronic Acid on Orthodontic Tooth Movement in Rats

Abstract The purpose of this study was to assess the effects of the administration of zoledronic acid (ZA) during orthodontic movement in rats. A hundred and twenty male Wistar rats were applied force of 30 cN with spring closed nickel-titanium to move the upper right first molar to mesial. In the Control Movement group (CM), only tooth movement was performed; the Control Acid Zoledronic group (CAZ) received a single dose (0.1 mg/kg) of ZA; the Experimental Acid Zoledronic group (EAZ) received a single dose (0.1 mg/kg) one week prior to the start of tooth movement; and the Control Without movement group (CWM) that received no drug and without application of tooth movement. The animals were euthanized after 3, 7 and 14 days. Tooth movement was measured using a caliper, the number of osteoclasts using TRAP staining, the expression of mature and immature collagen using picrosirius staining, and the presence of hyaline areas and root resorption using HE. The data were compared using two-way ANOVA, Tukey HSD, Games-Howell and chi-squared test, at the 5% significance level. It was observed a smaller number of osteoclasts and greater percentage of hyaline area in the EAZ group. There was no difference among the groups regarding bone remodeling, root resorption and tooth movement for all observed times.

Resumo A proposta deste estudo foi avaliar os efeitos da administração do ácido zoledrônico (ZA) durante a movimentação ortodôntica em ratos. Cento e vinte ratos Wistar, machos, foram submetidos a aplicação de uma força de 30 cN através de uma mola fechada de níquel-titânio para mover o primeiro molar superior direito para mesial. No grupo Controle Movimentação (CM), apenas a movimentação dentária foi realizada; o grupo Controle Ácido Zoledrônico (CAZ) recebeu uma única dose (0,1 mg/kg) de ZA; o grupo Experimental Ácido Zoledrônico (EAZ) recebeu uma única dose (0,1 mg/Kg) uma semana antes do início da movimentação dentária; e o grupo Controle Sem Movimentação (CWM) não receberam nenhum tipo de droga e não foi realizado movimentação dentária. Os animais foram eutanásiados após 3, 7 e 14 dias. A movimentação dentária foi mensurada através de um paquímetro, o número de osteoclastos utilizando coloração TRAP, a expressão do colágeno maturo e imaturo através da coloração Picrosírius, e a presença de áreas hialinas e reabsorção radicular utilizando HE. Os dados foram comparados utilizando ANOVA a dois critérios, Tukey HSD, Games-Howell e teste de qui-quadrado, ao nível de significância de 5%. Verificou-se menor número de osteoclastos e maior porcentagem de área hialina no grupo EAZ. Não houve diferença entre grupos quanto à neoformação óssea, reabsorção radicular e movimentação dentária em todos os tempos observados.

Arnica montana does not affect mast cell populations in experimentally induced oral ulcers in rats / Arnica montana não afeta populações de mastócitos em úlceras orais induzidas experimentalmente em ratos

BACKGROUND: Studies have shown that Arnica montana shows anti-inflammatory and antioxidant activities. It has been used in traditional medicine for the treatment of several disorders. The aim of this study was to investigate the effect of Arnica montana on mast cells during the wound healing of oral ulcers. METHOD: An ulcerated lesion was chemically induced on the tongue of 75 male albino rats and, then, treated topically for seven days using saline solution (control), Arnica montana gel or tincture. The animals were killed after 2nd, 7th, 14th, 21th and 42th day of treatment. The tongues were removed and subjected to routine laboratory (0.2% toluidine blue staining). The numbers of mast cell were determined in two regions: superficial and submucosa. RESULTS: The numbers of mast cells were significantly increased for all groups in the region of the deeper tissue when compared to the superficial region. No statistical difference was observed in mast cell numbers for each group. CONCLUSION: This study revealed that Arnica montana tincture and gel were unable to change mast cell population during wound healing of oral ulcer of rats. According to these results, the anti-inflammatory effects of Arnica montana were not related to inhibition of mast cell degranulation.

OBJETIVO: Sabe-se que a Arnica montana mostra atividade anti-inflamatória e anti-oxidante e tem sido usada em medicina tradicional para o tratamento de vários distúrbios. O objetivo deste estudo foi investigar o efeito da Arnica montana em mastócitos durante a cicatrização de feridas de úlceras orais. MÉTODO: Uma úlcera foi quimicamente induzida na língua de 75 ratos albinos machos e, em seguida, tratada topicamente durante sete dias, utilizando solução salina (controle), gel ou tintura de Arnica montana. Os animais foram sacrificados após 2, 7, 14, 21 e 42º dia de tratamento. As línguas foram removidas e submetidas a rotina de laboratório (coloração com 0,2% de azul de toluidina). A densidade de mastócitos foi determinada em duas regiões: superficial e submucosa. RESULTADOS: O número de mastócitos aumentou nitidamente para todos os grupos na região mais profunda do tecido peri-ulceroso, quando comparada à região superficial. Nenhuma diferença estatística foi observada no número de mastócitos entre os grupos. CONCLUSÃO: Este estudo revelou que a tintura ou o gel de Arnica montana foram incapazes de interferir na população de mastócitos durante a cicatrização da úlcera oral de ratos. De acordo com estes resultados, os efeitos anti-inflamatórios de Arnica montana não foram relacionados à inibição da degranulação dos mastócitos.

The effects of binge-pattern alcohol consumption on orthodontic tooth movement

OBJECTIVE: This study aimed to assess tissue changes during orthodontic movement after binge-pattern ethanol 20% exposure. METHODS: Male Wistar rats (n = 54) were divided into two groups. The control group (CG) received 0.9% saline solution, while the experimental group (EG) received 20% ethanol in 0.9% saline solution (3 g/kg/day). On the 30th day, a force of 25 cN was applied with a nickel-titanium closed coil spring to move the maxillary right first molar mesially. The groups were further divided into three subgroups (2, 14 and 28 days). Tartrate-resistant acid phosphatase and picrosirius were used to assess bone resorption and neoformation, respectively. Data were compared by two-way ANOVA, Tukey's HSD, Games-Howell and chi-square test. Significance level was set at 5%. RESULTS: There was a decrease in the number of osteoclasts in EG at day 28. The percentage of collagen showed no interaction between group and time. CONCLUSION: Binge-pattern 20% ethanol promoted less bone resorption at the end of tooth movement, thereby suggesting delay in tooth movement. .

OBJETIVO: objetivou-se avaliar as alterações teciduais decorrentes da administração de etanol a 20% no padrão binge, durante o movimento ortodôntico. MÉTODOS: foram utilizados ratos Wistar machos (n = 54), divididos em dois grupos, sendo Grupo Controle (GC), com administração de soro fisiológico a 0,9%; e Grupo e Experimental (GE), com administração de etanol a 20% em soro fisiológico a 0,9%, no volume de 3g/kg/dia. Após o 30º dia de administração, foi aplicada força de 25cN com mola fechada de níquel-titânio para mover o primeiro molar superior direito para mesial. Os grupos foram subdivididos nos subgrupos 2, 14 e 28 dias, correspondendo ao número de dias de movimentação dentária. Utilizou-se as colorações de fosfatase ácida-tartarato resistente e picrosírius para avaliar reabsorção óssea e neoformação óssea, respectivamente. Os dados foram comparados por ANOVA a dois critérios, Tukey HSD e Games-Howell, ao nível de significância de 5%. RESULTADOS: verificou-se diminuição no número de osteoclastos no GE II no 28º dia. A percentagem de colágeno não demonstrou alteração na interação grupo x tempo. CONCLUSÕES: o etanol no padrão binge a 20% promoveu menor reabsorção óssea no final da movimentação dentária, sugerindo atraso na movimentação dentária. .

Cellular proliferation markers in peripheral and central fibromas: a comparative study

ABSTRACT Objective: To perform a comparative study of the cellular proliferation in the peripheral and central fibromas. Material and Methods: Immunohistochemistry for PCNA and the AgNOR technique were performed in 9 cases of peripheral odontogenic fibroma (POF), in 4 cases of odontogenic fibroma (OdF), in 8 cases of peripheral ossifying fibroma (PEOF) and 7 cases of ossifying fibroma (OsF). The Kruskal-Wallis and Mann-Whitney tests were used for the statistical analyses. Results: Mesenchymal component of the central lesions presented a higher mean number of AgNOR per nucleus and PCNA index than did the peripheral lesions (P≤0.05). The mean number of AgNOR per nucleus in the epithelial component proved to be higher in the OdF than in the POF (P≤0.05). The mesenchymal and epithelial components presented similar mean numbers of AgNOR per nucleus and PCNA index in the OdF, as well as a similar mean number of AgNOR per nucleus in the POF. Conclusions: The mesenchymal component may well play a role in the differences between the biological behaviour of the central lesions as compared to the peripheral lesions. Moreover, considering that the epithelial and mesenchymal components in odontogenic fibromas presented a similar proliferation index, more research is warranted to understand the true role of the epithelial components, which are believed to be inactive in nature, as well as in the development and biological behaviour of these lesions. .

Imuno-expressão da metalotioneída em cistos e tumores odontogênicos / Metallothionein immunoexpression in odontogenic cysts and in odontogenic tumours

Cistos e tumores odontogênicos são lesões originadas dos tecidos que formam os dentes e apresentam diferentes comportamentos biológicos. A metalotioneíra (MT) é relacionada à homeostase de metais, regulação da diferenciação e proliferação celular e inibição da apoptose. Com relação aos cistos e tumores odontogênicos, a MT poderia ter um papel na regulação da diferenciação e proliferação celuar e na inibição da apoptose, refletindo no comportamento biológico. Os objetivos são avaliar e comparar a expressão da MT entre: 1) cistos odontogêncios e tumor odontogênico ceratocístico (TOC); 2) TOC associados à Síndrome do Carcinoma Basocelular Nevóide (SCBN) e não associados; 3) tumores odontogênicos benignos. Objetivou-se também correlacionar a imuno-expressão da MT com a proliferação celular e com a inflamação. A amostra incluiu cisto radicular (CR), cisto dentígero (CD), TOC (primário associado ou não à (SCBN), cisto odontogênico ortoceratinizado (COO), ameloblastoma sólido (ABS), tumor odontogênico escamoso (TOE), tumor odontogênico adenomatóide (TOA), tumor odontogênico cístico calcificante (TOCC) e tumor odontogênico epitelial calcificante (TOEC). Foi realizada imunoistoquímica para MT, Ki-67 e PCNA...

Retrospective analysis of oral peripheral nerve sheath tumors in Brazilians

Traumatic neuroma, neurofibroma, neurilemmoma, palisaded encapsulated neuroma and malignant peripheral nerve sheath tumor (MPNST) are peripheral nerve sheath tumors and present neural origin. The goal of this study was to describe the epidemiological data of oral peripheral nerve sheath tumors in a sample of the Brazilian population. Biopsies requested from the Oral Pathology Service, School of Dentistry, Federal University of Minas Gerais (MG, Brazil), between 1966 and 2006 were evaluated. Lesions diagnosed as peripheral nerve sheath tumors were submitted to morphologic and to immunohistochemical analyses. All cases were immunopositive to the S-100 protein. Thirty-five oral peripheral nerve sheath tumors were found, representing 0.16% of all lesions archived in the Oral Pathology Service. Traumatic neuroma (15 cases) most frequently affected the mental foramen. Solitary neurofibroma (10 cases) was more frequently observed in the palate. Neurofibroma associated with neurofibromatosis type I (2 cases) was observed in the gingival and alveolar mucosa. Neurilemmoma (4 cases) was more commonly observed in the buccal mucosa. Malignant peripheral nerve sheath tumors (3 cases) occurred in the mandible, palate, and tongue. Palisaded encapsulated neuroma (1 case) occurred in the buccal mucosa. The data confirmed that oral peripheral nerve sheath tumors are uncommon in the oral region, with some lesions presenting a predilection for a specific gender or site. This study may be useful in clinical dentistry and oral pathology practice and may be used as baseline data regarding oral peripheral nerve sheath tumors in other populations.

Primary diffuse large B-cell lymphoma of the oral cavity

Lymphomas arising within the oral cavity account for only 3.5 percent of all oral malignancies. Diffuse large B-cell lymphoma is a non-Hodgkin lymphoma subtype characterized by diffuse proliferation of large neoplastic B lymphoid cells. This paper reports a case of diffuse large B-cell lymphoma affecting the oral cavity of a Brazilian woman, along with its clinical, microscopical, immunohistochemical, and molecular features.

Linfomas correspondem a 3,5 por cento de todos os casos de lesões malignas de boca. O linfoma difuso de grandes células B é um subtipo de linfoma não-Hodgkin caracterizado pela proliferação difusa de células linfóides B. Este artigo relata um caso de linfoma difuso de grandes células B localizado na cavidade bucal de uma mulher brasileira, incluindo os achados clínicos, microscópicos, imuno-histoquímicos e moleculares.

Prevalence of oral hemangioma, vascular malformation and varix in a Brazilian population

Hemangioma, vascular malformation and varix are benign vascular lesions, common in the head and neck regions. Studies about the prevalence of these lesions in the oral cavity are scarce. The aim of this study was to estimate the prevalence of and to obtain clinical data on oral hemangioma, vascular malformation and varix in a Brazilian population. Clinical data on those lesions were retrieved from the clinical forms from the files of the Oral Diagnosis Service, School of Dentistry, Federal University of Minas Gerais, Brazil, from 1992 to 2002. Descriptive analysis was performed. A total of 2,419 clinical forms in the 10-year period were evaluated, of which 154 (6.4 percent) cases were categorized as oral hemangioma, oral vascular malformation or oral varix. Oral varix was the most frequent lesion (65.6 percent). Females had more oral hemangioma and oral varix than males. Oral vascular malformation and oral varix were more prevalent in the 7th and 6th decades, respectively. Oral hemangioma and oral varix were more prevalent in the ventral surface of the tongue and oral vascular malformation, in the lips. Oral hemangioma was treated with sclerotherapy (54.5 percent), and vascular malformation was managed with sclerotherapy and surgery (19.4 percent each). The data of this study suggests that benign vascular lesions are unusual alterations on the oral mucosa and jaws.

Hemangioma, malformação vascular e variz são lesões vasculares benignas comuns na região de cabeça e pescoço. Estudos sobre a prevalência dessas lesões em boca são escassos. O objetivo deste estudo foi estimar a prevalência e realizar um levantamento de dados clínicos de hemangioma, malformação vascular e variz de boca. Dados clínicos dessas lesões foram consultados em fichas clínicas do arquivo do Serviço de Diagnóstico Oral da Universidade Federal de Minas Gerais, Brasil, no período de 1992 a 2002. Uma análise descritiva foi realizada. Foram obtidas neste período de 10 anos 2.419 fichas clínicas. Cento e cinqüenta e quatro (6,4 por cento) casos foram categorizados como hemangioma, malformação vascular e variz de boca. Variz de boca foi a lesão mais freqüente (65,6 por cento). Mulheres foram mais acometidas pelos hemangiomas e varizes de boca. Malformação vascular e variz de boca foram mais prevalentes na 7ª e 6ª décadas de vida, respectivamente. A localização prevalente do hemangioma e da variz de boca foi a superfície ventral da língua, e da malformação vascular, os lábios. Hemangioma de boca foi tratado com escleroterapia em 54,5 por cento dos casos e a malformação vascular com escleroterapia e cirurgia em 19,4 por cento cada. Este estudo sugere que lesões vasculares benignas são alterações incomuns na mucosa bucal e nos maxilares.