Avaliação da alteração do plano oclusal em cirurgias ortognáticas combinadas com utilização de fixação interna rígida em pacientes com padrão facial de Classe II

OBJETIVO: avaliar a estabilidade de cirurgias bimaxilares com fixação interna rígida, na qual promoveu-se uma rotação anti-horária da mandíbula e conseqüente redução do ângulo do plano oclusal. METODOLOGIA: foram estudados 15 pacientes com padrão facial de Classe II e deficiência mandibular. Os movimentos cirúrgicos foram avaliados por meio de medidas lineares e angulares realizadas no programa CefX, obtidas de telerradiografias cefalométricas em norma lateral em três diferentes tempos: (T0) pré-operatório, (T1) pós-operatório imediato e (T2) pós-operatório de no mínimo 6 meses. RESULTADOS E CONCLUSÕES: os resultados demonstraram que a cirurgia bimaxilar promove mudanças faciais significativas e, principalmente, que a rotação anti-horária da mandíbula com redução do ângulo do plano oclusal mostrou-se estatisticamente estável, sendo uma opção confiável em cirurgias de pacientes com padrão facial de Classe II com deficiência mandibular.

Early Bone Healing and Biomechanical Fixation of Dual Acid-Etched and As-Machined Implants with Healing Chambers: An Experimental Study in Dogs

Purpose: To evaluate the biomechanical fixation, bone-to-implant contact (BIC), and bone morphology of screw-type root-form implants with healing chambers with as-machined or dual acid-etched (DAE) surfaces in a canine model. Materials and Methods: The animal model included the placement of machined (n = 24) and DAE (n = 24) implants along the proximal tibiae of six mongrel dogs, which remained in place for 2 or 4 weeks. Following euthanasia, half of the specimens were subjected to biomechanical testing (torque to interface failure) and the other half were processed for histomorphologic and histomorphometric (%BIC) assessments. Statistical analyses were performed by one-way analysis of variance at the 95% confidence level and the Tukey post hoc test for multiple comparisons. Results: At 4 weeks, the DAE surface presented significantly higher mean values for torque to interface failure overall. A significant increase in %BIC values occurred for both groups over time. For both groups, bone formation through the classic appositional healing pathway was observed in regions where intimate contact between the implant and the osteotomy walls occurred immediately after implantation. Where contact-free spaces existed after implantation (healing chambers), an intramembranous-like healing mode with newly formed woven bone prevailed. Conclusions: In the present short-term evaluation, no differences were observed in BIC between groups; however, an increase in biomechanical fixation was seen from 2 to 4 weeks with the DAE surface. INT J ORAL MAXILLOFAC IMPLANTS 2011;26:75-82

Effect of Severe Dietary Magnesium Deficiency on Systemic Bone Density and Removal Torque of Osseointegrated Implants

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of magnesium intake deficiency on bone metabolism and bone tissue around osseointegrated implants

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anatomic study of the mandibular foramen, lingula and antilingula in dry mandibles, and its statistical relationship between the true lingula and the antilingula

The authors verified the anatomical location of the mandibular foramen, lingula and antilingula in dry mandibles, aiming to obtain information that could be used when performing mandibular osteotomies. Forty-four mandibles (88 sides) were evaluated. The distances were measured using a sliding calliper, with the mandibles fixed in a reproducible position. Results showed that the mandibular foramen is on average 5.82 mm below the lingula. Regarding the statistical comparison between the mandibular foramen entrance and the anti lingula position, there is no correlation between the position of those two structures in the studied sample. The mandibular foramen is slightly posterior in relation to the centre of the ramus. The lingula is an important anatomic landmark for ramus surgery, and for determining the distance to the mandibular foramen entrance. The use of the antilingula as a landmark for the position of the vertical ramus osteotomy is not recommended.

Frontal sinus obliteration with heterogeneous corticocancellous bone versus spontaneous osteoneogenesis in monkeys (Cebus apella): Histologic analysis

Purpose: In this study, we evaluated the results of spontaneous osteoneogenesis of the frontal sinus with autogenous bone plug versus obliteration with heterogeneous (human) bone in monkeys (Cebus apella).Materials and Methods: Eight young adult male C apella monkeys underwent an ostectomy of the anterior wall of the frontal sinus, removal of the sinus mucosa, and inner decortication of the bony walls and then were divided into 2 groups of 4 each, as follows. Group I monkeys underwent obliteration of the nasofrontal ducts with a free segment of frontallis muscle and corticocancellous heterogeneous bone, followed by full obliteration of the sinus with corticocancellous heterogeneous bone (Dayton Regional Tissue Bank, Dayton, OH). Group II monkeys underwent obliteration of the nasofrontal ducts with a frontal muscle segment and tibial autogenous bone plug, without full obliteration of the frontal sinus. In all animals, the sinus anterior wall was repositioned and fixed with 1.0 plate and screws. The monkeys were killed after 180 days, and routine laboratory procedures were followed for hematoxylin-eosin staining and histologic evaluation of the specimens.Results: the 2 studied techniques were both effective in obliterating the frontal sinus with newly formed bone. The nasofrontal ducts were obliterated by new bone formation or fibrous tissue (1 animal only).Conclusions: Both methods used for frontal sinus obliteration were effective; the heterogeneous bone (human bone) was well tolerated and presented low antigenicity. The nasofrontal duct obliteration with autogenous muscle associated with autogenous tibial bone (group II) or with heterogeneous bone (group I) was effective, isolating the frontal sinus from the nasal cavity. The spontaneous obliteration resulted, in the period analyzed, in earlier bone maturation compared with the obliteration by heterogeneous bone. (C) 2003 American Association of Oral and Maxillofacial Surgeons.

Vida e teatro em Guimarães Rosa: Grande sertão: veredas e pirlimpsiquice

Este artigo inicia-se com uma exposição sucinta da metáfora do teatro, tal como aparece em Platão. em seguida, após levantamento dos momentos capitais da literatura, investiga-se a metáfora em Guimarães Rosa, no Grande sertão: veredas e no conto Pirlimpsiquice. No Grande sertão, a atuação no palco é tomada como equivalente ao desempenho na vida. Teatro e vida são, portanto, domínios que se identificam. Para isto, concorrem a religião cristã e o pensamento de Plotino. em Pirlimpsiquice, o Autor investiga por menorizadamente os limites e aproximações entre teatro e vida, sendo que o grau mínimo da metáfora é conferido pelas práticas histórica e cultural. Por fim, retomando a polêmica de Hegel com o platonismo, conclui-se que a representação e a vida estão amalgamadas, numa constante dialetização entre história e cultura.

Effect of Citrus aurantium l. essential oil on muscle regeneration in mdx mice

Duchenne muscular dystrophy (DMD) is a severe X-linked recessive disorder characterized by the progressive loss of muscular strength. Mdx mutant mice show a marked deficiency in dystrophin, which was related to muscle membrane stability. The aim of this study was to verify the possible protective anti-inflammatory effect of citrus oil on mdx muscle fibers. Thus, adult male and female mdx mice (014/06-CEEA) were divided into control and citrus-treated. After 60 days of treatment, one ml of blood was collected for creatine kinase (CK) test. Diaphragm, sternomastoideus, anterior tibial and gastrocnemius muscles were removed and processed according to histological routine methods. The observed alterations indicate a direct effect of citrus. Recent studies have improved the diagnosis of muscular diseases but with no definitions of efficient treatments. Intervention with several therapies is important to many patients presenting muscular dystrophy, which enables them to live longer and be more active, while there is no development of gene therapies.

Skeletal muscles with antagonistic muscular actions: morphological, contractile and metabolic characteristics

The muscles can perform the same function in a specific segment (muscles of fast and slow contraction), and at the same time be antagonistic in relation to muscular action (flexors or extensors). The present research aimed to study the morphology, frequency and metabolism of fiber types and the contractile characteristics of extensor and flexors muscles of rabbit. We studied muscles anterior tibialis (AT), flexor digitorum supeficialis (FDS), extensor digitorum longus (EDL) and posterior tibialis (PT). The muscles were submitted to the techniques HE, NADH-TR and myofibrillar ATPase. In EDL and PT extensor muscles, the frequencies of red (SO + FOG) and white fibers (FG) were 68.77% and 31.23% versus 58.87% and 41.13%, respectively. In the AT and FDS flexor muscles, these frequencies were 75.14% and 24.86% versus 73.89% and 26.11%, respectively. In extensor muscles, the percentage of slow contraction fibers was 8.05% in EDL and 9.74% in PT, and in fast contraction, 91.95% in EDL and 90.26% in PT. In flexors, the slow contraction frequencies were 12.35% in AT and 8.17% in FDS, and in fast contraction, 87.65% and 91.83%, respectively. Skeletal muscles with antagonistic muscular actions (flexors and extensors) the morphological, contractile and metabolic characteristics are identical.

Myotoxic effects of mastoparan from Polybia paulista (Hymenoptera, Epiponini) wasp venom in mice skeletal muscle

In a previous study, we showed that the Polybia paulista wasp venom causes strong myonecrosis. This study was undertaken to characterize the myotoxic potency of mastoparan (Polybia-MPII) isolated from venom (0.25 mu g/mu l) and injected in the tibial anterior (TA) muscle (i.m.) of Balb/c mice. The time course of the changes was followed at muscle degenerative (3 and 24 h) and regenerative (3, 7, and 21 days) periods (n = 6) after injection and compared to matched controls by calculation of the percentage of cross-sectional area affected and determination of creatine kinase (CK) activity (n = 10). The results showed that although NIP was strongly myotoxic, its capacity for regeneration was maintained high. Since the extent of tissue damage was not correlated with the CK serum levels, which remained very low, we raised the hypothesis that the enzyme underwent denaturation by the peptide. Evidence suggested that MP induced the death of TA fibers by necrosis and apoptosis and had the sarcolemma as its primordial target. Given its amphiphilic polycationic nature and based on the vast spectrum of functions attributed to the peptide, we suggest that MP interaction with cell membrane impaired the phosphorylation of dystrophin essential for sarcolemma mechanical stability, and disturbed Ca2+ mobilization with obvious implications on sarcoplasmic reticulum and mitochondrial functioning. (c) 2007 Elsevier Ltd. All rights reserved.

Inflammation and apoptosis induced by mastoparan Polybia-MPII on skeletal muscle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mastoparan effects in skeletal muscle damage: An ultrastructural view until now concealed

Animal venoms have been valuable sources for development of new drugs and important tools to understand cellular functioning in health and disease. The venom of Polybia paulista, a neotropical social wasp belonging to the subfamily Polistinae, has been sampled by headspace solid phase microextraction and analyzed by gas chromatography-mass spectrometry. Recent study has shown that mastoparan, a major basic peptide isolated from the venom, reproduces the myotoxic effect of the whole venom. In this study, Polybia-MPII mastoparan was synthesized and studies using transmission electron microscopy were carried out in mice tibial anterior muscle to identify the subcellular targets of its myotoxic action. The effects were followed at 3 and 24 h, 3, 7, and 21 days after mastoparan (0.25 mu g/mu L) intramuscular injection. The peptide caused disruption of the sarcolemma and collapse of myofibril arrangement in myofibers. As a consequence, fibers presented heteromorphic amorphous masses of agglutinated myofilaments very often intermingled with denuded sarcoplasmic areas sometimes only surrounded by a persistent basal lamina. To a lesser extent, a number of fibers apparently did not present sarcolemma rupture but instead appeared with multiple small vacuoles. The results showed that sarcolemma, sarcoplasmic reticulum (SR), and mitochondria were the main targets for mastoparan. In addition, a number of fibers showed apoptotic-like nuclei suggesting that the peptide causes death both by necrosis and apoptosis. This study presents a hitherto unexplored view of the effects of mastoparan in skeletal muscle and contributes to discuss how the known pharmacology of the peptide is reflected in the sarcolemma, SR, mitochondria, and nucleus of muscle fibers, apparently its subcellular targets.

Effects of swimming training on bone mass and the GH/IGF-1 axis in diabetic rats

The aim of this study was to examine the influence of moderate swimming training on the GH/IGF-1 growth axis and tibial mass in diabetic rats. Male Wistar rats were allocated to one of four groups: sedentary control (SC), trained control (TC), sedentary diabetic (SD) and trained diabetic (TD). Diabetes was induced with alloxan (35 mg/kg b.w.). The training program consisted of a 1 h swimming session/day with a load corresponding to 5% of the b.w., five days/week for six weeks. At the end of the training period, the rats were sacrificed and blood was collected for quantification of the serum glucose, insulin, GH, and IGF-1 concentrations. Samples of skeletal muscle were used to quantify the IGF-1 pepticle content. The tibias were collected to determine their total area, length and bone mineral content. The results were analyzed by ANOVA with P < 0.05 indicating significance. Diabetes decreased the serum levels of GH and IGF-1, as well as the tibial length, total area and bone mineral content in the SD group (P < 0.05). Physical training increased the serum IGF-1 level in the TC and TD groups when compared to the sedentary groups (SC and SD), and the tibial length, total area and bone mineral content were higher in the TD group than in the SD group (P < 0.05). Exercise did not alter the level of IGF-1 in gastrocnemius muscle in nondiabetic rats, but the muscle IGF-1 content was higher in the TD group than in the SD group. These results indicate that swimming training stimulates bone mass and the GH/IGF-1 axis in diabetic rats. (c) 2006 Elsevier Ltd. All rights reserved.

Análise qualitativa dos efeitos da sonoforese com Arnica montana sobre o processo inflamatório agudo do músculo esquelético de ratos

Este estudo visou verificar o efeito da sonoforese com Arnica montana sobre a fase inflamatória aguda de uma lesão muscular. Para isso, 40 ratos Wistar machos, lesados cirurgicamente, foram divididos em 4 grupos: controle (C), 10 ratos lesados e não tratados; grupo ultra-som (US), 10 lesados, tratados com US; grupo ultra-som com arnica (US+A), 10 ratos lesados, tratados com sonoforese de gel de arnica; grupo arnica (A), 10 ratos lesados, tratados com massagem de gel de arnica. O tratamento dos três grupos foi iniciado 24h após a lesão, sendo aplicado uma vez ao dia durante 3 minutos, por três dias. Quatro dias após a lesão, os animais foram sacrificados e o terço médio do músculo tibial anterior lesado foi removido e tratado histologicamente. Os resultados da análise qualitativa mostram que, no grupo C, formou-se um intenso infiltrado de células inflamatórias no espaço intersticial e um processo de regeneração apenas iniciado. Nos grupos US e US+A foi detectado um avançado processo inflamatório, com tecido conjuntivo mais organizado e consistente. No grupo A foi detectada diminuição no número de células inflamatórias e uma desorganização em sua disposição, o que poderia levar a um atraso no processo de regeneração. Conclui-se que os grupos que receberam a aplicação do ultra-som e ultra-som com arnica apresentaram semelhante aceleração do processo inflamatório agudo, sugerindo ineficácia da sonoforese quando comparada à aplicação de apenas ultra-som.

Influence of ultrasound and physical activity on bone healing

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)