Estudo cefalométrico das alterações no perfil facial em pacientes Classe III dolicocefálicos submetidos à cirurgia ortognática bimaxilar

O presente estudo avaliou as modificações no perfil facial de 15 pacientes portadores de má oclusão Classe III esquelética que foram submetidos a tratamento ortodôntico pré-cirúrgico e cirurgia ortognática bimaxilar estabilizada com fixação rígida. Oito pacientes foram submetidos à mentoplastia. Foram utilizadas telerradiografias pré-cirúrgicas (T1) e pós-cirúrgicas (T2) com um intervalo mínimo de 6 meses. Foram analisados deslocamentos horizontais e verticais em pontos do tecido ósseo e tecido mole. Foi realizada uma comparação entre os casos tratados com e sem mentoplastia (teste t) mostrando não haver diferenças entre os grupos. A regressão linear múltipla evidenciou uma correlação significante no sentido horizontal para os pontos Pg e Pgm e vertical para os pontos Me e Mem. Foi encontrada baixa correlação para movimentos no sentido horizontal nos pontos Sena e A, e para os pontos Pn, Sn e Ph. No sentido vertical, os deslocamentos mais evidentes foram entre os pontos Pg, Gn e Me e Sena e A, porém com correlações de baixa intensidade.

Intrusion of teeth with class III furcation: a clinical, histologic and histometric study in dogs

Aim: To assess orthodontic intrusion effects on periodontal tissues in dogs' pre-molars with class III furcations treated with open flap debridement (OFD) or with guided tissue regeneration (GTR) associated to bone autograft (BA).Material and Methods: Class III furcations were created in the pre-molars of seven mongrel dogs. After 75 days, teeth were randomly treated with OFD or GTR/BA. After 1 month, metallic crowns were assembled on pre-molars and connected apically to mini-implants by nickel-titanium springs. Teeth were randomly assigned to orthodontic intrusion (OFD+I and GTR/BA+I) groups or no movement (OFD and GTR/BA) groups. Dogs were sacrificed after 3 months of movement and 1 month retention.Results: All class III furcations were closed or reduced to class II or I in the intrusion groups, while 50% of the lesions in non-moved teeth remained unchanged. Intruded teeth presented higher probing depth and lower gingival marginal level than non-moved teeth (p < 0.01). Clinical attachment gain was reduced in the intrusion groups by the end of retention (p < 0.05). OFD+I presented smaller soft tissue area and larger bone tissue area than other groups (p < 0.05).Conclusion: Orthodontic intrusion with anchorage via mini-implants improved the healing of class III furcation defects after OFD in dogs. GTR/BA impaired those results.

Clinical and radiographic changes around dental implants inserted in different levels in relation to the crestal bone, under different restoration protocols, in the dog model

Background: The aim of the present study was to evaluate clinical and radiographic changes that occur around dental implants inserted in different levels in relation to crestal bone under different restoration protocols.Methods: Thirty-six implants were inserted in the edentulous mandible of six mongrel dogs. Each implant was assigned to an experimental group according to the distance from the top of the implant to the crestal bone: Bone Level (at crestal bone level), Minus 1 (1 mm below crestal bone), or Minus 2 (2 mm below crestal bone). Each hemimandible was submitted to a restoration protocol: conventional (prosthesis was installed 120 days after implant placement, including 30 days with healing cap) or immediate (prosthesis was installed 24 hours after implant placement). Fixed partial prostheses were installed bilaterally in the same day. After 90 days, clinical and radiographic parameters were evaluated.Results: As long as the implants were inserted in more apical positions, the first bone-to-implant contact (fBIC) was positioned more apically (P<0.05). However, the apical positioning of the implants did not influence the ridge loss or the position of the soft tissue margin (PSTM) (P>0.05). In addition, in immediately restored sites, the PSTM was located significantly more coronally than that in conventionally restored sites (P=0.02).Conclusions: Despite the more apical positioning of the fBIC, the height of the peri-implant soft tissues and ridge was not jeopardized. Moreover, the immediate restoration protocol was beneficial to the maintenance of the PSTM. Further studies are suggested to evaluate the significance of these results in longer healing periods.

Comparison of Biomaterial Implants in the Dental Socket: Histological Analysis in Dogs

Background:Bone graft procedures have been used commonly in buco-maxillo-facial surgery. For this reason, many researchers have evaluated the bone substitutes.Purpose:The present study evaluated soft and hard tissue reactions to two different hydroxyapatites HAs (synthetic HA and natural HA) and bioactive glass implanted into the sockets immediately after extraction.Materials and Methods:First and third upper and lower premolars, on both sides, were extracted from six female dogs. The alveolar sockets were randomly assigned to four groups: Group 1 - control (unfilled), Group 2 - filled with synthetic hydroxyapatite, Group 3 - filled with bovine bone mineral (natural HA), and Group 4 - filled with bioactive glass. The animals were euthanized at 4 weeks (n = 2), 8 weeks (n = 2), and 28 weeks (n = 2) after extraction. The mandible and maxilla of each animal were removed for histological analysis to determine soft tissue reactions, newly formed bone, bone characteristics, and presence or absence of implanted materials.Results:Most particles of synthetic hydroxyapatite had bone formation on their surface, although some particles showed a layer of fibrous connective tissue. The bovine bone mineral group exhibited particles partially replaced with bone formation. The bioactive glass group showed particles with a thin layer of calcified tissue, but was absent in some specimens, suggesting complete resorption.Conclusion:All biomaterials had similar behavior. Bovine bone mineral, compared to synthetic hydroxyapatite and bioactive glass, showed a larger number of particles covered with osseous tissue. All biomaterials interfered with the socket repair process.

Biologic width changes around loaded implants inserted in different levels in relation to crestal bone: histometric evaluation in canine mandible

Objectives: The aim of the present study was to evaluate histometric changes around dental implants inserted at different levels in relation to the crestal bone, under different loading conditions.Material and methods: Thirty-six implants were inserted in the edentulous mandible of six mongrel dogs. Each implant was assigned to an experimental group according to the distance from the top of the implant to the crestal bone: Bone Level (at the crestal bone level), Minus 1 (1 mm below the crestal bone) or Minus 2 group (2 mm below the crestal bone). Each hemimandible was submitted to a loading protocol: conventional or immediate restoration. After 90 days, the animals were killed. Specimens were processed, and measurements were performed concerning the length of soft and hard peri-implant tissues. Data were analyzed using ANOVA and Student's t test (alpha=5%).Results: Among conventionally restored sites, the distance from the most coronal position of soft tissue margin (PSTM) and first bone-implant contact (fBIC) was greater for Minus 2 than for Bone Level and Minus 1 sites (P=0.03), but significant differences were not observed among immediately restored sites. Differences among groups were not observed concerning the PSTM, and the distance from the implant-abutment junction to fBIC. Greater amounts of lateral bone loss were observed for conventionally than for immediately restored sites (P=0.006).Conclusions: These findings suggest that the apical positioning of the top of the implant may not jeopardize the position of soft peri-implant tissues, and that immediate restoration can be beneficial to minimize lateral bone loss. Further studies are suggested to evaluate the clinical significance of these results in longer healing periods.

Tunnel technique with a surgical maneuver to increase the graft extension: Case report with a 3-year follow-up

Background: This article reports a clinical case with a 3-year follow-up in which a subepithelial connective tissue graft (SCTG) was used with the tunnel technique to treat multiple gingival recessions, and describes a technique used to enlarge the extension of the graft.Methods: A 41 -year-old female patient was referred for evaluation and treatment of maxillary multiple recessions. Following basic therapy, the plaque index was 23%, and the gingival index was 12%. Thus, SCTG with the tunnel technique was proposed to provide root coverage of Miller Class I recession on teeth #8 through #11 and a Miller Class III recession on tooth #12. After the donor area had been prepared, SCTG was removed and split cross-sectionally to lengthen it. The graft was placed through the tunnel and sutured.Results: Two weeks after the surgical procedure, the tissue color was nearly homogeneous with some reddish regions where the connective tissue was left uncovered, and there were no signs of incisions or suture marks. After 3 years of follow-up, the mean coverage of the recessions was 2.2 +/- 0.7 mm (74.2%), which corresponded to the gain of keratinized tissue. In addition, a gain in tissue thickness was observed.Conclusion: In a long-term evaluation, the tunnel technique with the elongated SCTG was used successfully for treatment of multiple gingival recessions with an increase of the soft tissue volume and gain of keratinized tissue.

Análise histológica em tecido epitelial sadio de ratos Wistar (in vivo) irradiados com diferentes intensidades do ultrassom

CONTEXTUALIZAÇÃO: O Ultrassom (US) é um dos recursos físicos amplamente utilizado e pesquisado nos tratamentos de fisioterapia. Sabe-se que diante de uma escassa literatura sobre efeitos do US em tecidos sadios, muitos profissionais fisioterapeutas acabam realizando aplicações infundadas de métodos e parâmetros. OBJETIVO: Avaliar possíveis alterações histológicas e morfométricas do tecido sadio in vivo de ratos Wistar irradiados com diferentes intensidades de US. MÉTODOS: Trinta ratos da linhagem Wistar, distribuídos aleatoriamente em cinco grupos de seis animais cada foram tratados na região dorsal do lado direito numa área de 4cm². O lado esquerdo serviu como controle. O tratamento foi feito durante quatro dias com 2 minutos de irradiação. Verificou-se a intensidade de saída com dosímetro de precisão antes das aplicações. Analisou-se a histologia e a morfometria por meio do software Image Tool. RESULTADOS: Observou-se um discreto infiltrado inflamatório e adelgaçamento das fibras da derme, principalmente dos grupos irradiados com 1.5 e 2W/cm². Notou-se também um aumento na espessura da epiderme nas amostras dos animais irradiados. Para avaliar os resultados quantitativos, utilizou-se como análise estatística ANOVA one way e o teste post hoc de Tukey. Na espessura da epiderme, obtiveram-se diferenças significativas entre grupo controle e os grupos irradiados com 1.0, 1.5 e 2.0W/cm². CONCLUSÃO: Sob ação do US nas doses maiores houve alterações na epiderme e derme, respectivamente, o aumento da espessura e proliferação com adelgaçamento das fibras colágenas, o que alerta para possíveis implicações do uso do US em estética.

Temporal response pattern of biochemical analytes in experimental diabetes

The activities of the enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LD), creatine kinase (CK), amylase (AMS) and angiotensin converting enzyme (ACE) have been used to assess the toxic effects of xenobiotics that have hypoglycaemic action in hepatic, pancreatic, renal and muscle tissue. Using a validated experimental model of diabetes mellitus in rats, we ascertained whether this syndrome itself affected the serum activities of these enzymes over a 53-day period. Levels of hepatic enzymes AST, ALT and ALP were higher in the streptozotocin (STZ)diabetic rats (group D), but were controlled by insulin therapy (group DI). AMS was reduced in group D and unchanged in group DI rats. Proteinuria was detected 1 day after STZ administation and partially controlled by insulin (group DI); its early presence in group D rats, and the lack of any change in serum ACE in this group, indicates that proteinuria is the better marker for microangiopathy. Microscopic examination of liver, kidney, heart and skeletal muscles (soleus and extensor digitorum longus) revealed various alterations in group D rat tissues, which were less pronounced in group DI. The liver, pancreas and kidney tissue-damage was consistent with the altered serum levels of AST, ALT, ALP and AMS and proteinuria. We conclude that: (i) rigorous control is required when these serum-enzyme levels are used as indicators of tissue toxicity in experimental diabetes, and (ii) LD, CK and bilirubin serum levels, which are unaffected by diabetes, can be used when testing effects of xenobiotics on tissues.

Morphological alterations in the epithelium of the oral mucosa of rats (Rattus norvegicus) submitted to long-term systemic nicotine treatment

Smoking is considered to be the most albeit preventable cause of diseases and premature deaths in the history of mankind. The local action of tobacco on the oral mucosa can cause precancerous and cancerous lesions. However, there is not enough evidence to establish all the systemic effects caused by nicotine on the organism. Thus, the aim of the present study was to characterize the cellular changes of the cheek mucosa of rats submitted to long-term systemic nicotine treatment. Twenty male rats were divided into two experimental groups: a nicotine group and a control group, each consisting of 10 animals. The nicotine group was injected daily with 0.250 mg of nicotine per 100 g of body weight. All animals received a solid diet and water ad libitum. After 90 days of treatment, all animals were weighed and sacrificed. Samples of cheek mucosa were collected for light and transmission electron microscopy. The results revealed oral epithelium containing atypical cells that were characterized by atrophy, cell membrane disorganization and tissue damage. It was concluded that systemic administration of nicotine damaged the cellular integrity of the oral mucosa, impairing tissue function and predisposing the tissue to the action of different pathogenic agents and also to that of other carcinogenic substances present in tobacco. (c) 2006 Elsevier Ltd. All rights reserved.

Structural and Functional Studies of a Bothropic Myotoxin Complexed to Rosmarinic Acid: New Insights into Lys49-PLA(2) Inhibition

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

Comparative structural studies on Lys49-phospholipases A(2) from Bothrops genus reveal their myotoxic site

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

Effect of alpha-tocopherol on superoxide radical and toxicity of cadmium exposure

Contamination with cadmium compounds poses high potential risk for the health of populations and for this reason the treatment of their toxic effects should urgently be established. The present study was carried out to determine whether or-tocopherol intake can protect tissues against damage induced by cadmium, and to clarify the contribution of superoxide radicals (O-2(-)) in this process. Cadmium chloride was tested for tissue damage by a single intraperitoneal injection of Cd2+ ions (2 mg Kg(-1)). To determine the potential therapeutic effect of Vitamin E, a group of Cd2+-treated rats received a drinking solution of or-tocopherol (40 mg l(-1)) for 15 days. Cadmium induced increased serum creatinine and total lactate dehydrogenase, reflecting renal and cardiac damage. The increased lipoperoxide and decreased Cu-Zn superoxide dismutase levels indicated the generation of superoxide radicals in cadmium-treated rats. Tocopherol induced increased serum high-density lipoprotein and depressed the toxic effects of Ca2+ alone, since creatinine and lactate dehydrogenase determinations were recovered to the control values. Tocopherol decreased lipoperoxide and led the superoxide dismutase activities to approach those of the control values. We concluded that superoxide radicals are produced as mediators of cadmium toxicity. Tocopherol possesses a significant anti-radical activity and inhibits the cadmium effect on superoxide dismutase activity. Tocopherol also protected tissues from the toxic effects of cadmium by a direct antioxidant action which decreased lipoperoxide formation.

Toxicity of copper intake: lipid profile, oxidative stress and susceptibility to renal dysfunction

The present study was carried out to investigate the effects of copper (Cu) intake on lipid profile, oxidative stress and tissue damage in normal and in diabetic condition. Since diabetes mellitus is a situation of high-risk susceptibility to toxic compounds, we examined potential early markers of Cu excess in diabetic animals. Male Wistar rats, at 60-days-old were divided into six groups of eight rats each. The control(C) received saline from gastric tube, the no-diabetic(Cu-10), treated with 10 mg/kg of Cu(Cu(++)-CuSO(4), gastric tube), no-diabetic with Cu-60mg/kg(Cu-60), diabetic(D), diabetic low-Cu(DCu-10) and diabetic high-Cu(DCu-60). Diabetes was induced by an ip injection of streptozotocin (60mg/kg). After 30 days of treatments, no changes we're observed in serum lactate dehydrogenase, alanine transaminase and alkaline phosphatase; indicating no adverse effects on cardiac and hepatic tissues. D-rats had glucose intolerance and dyslipidemic profile. Cholesterol and LDL-cholesterol were higher in Cu-60 and DCu-60 than in C, Cu-10 and D and DCu-10 groups respectively. Cu-60 rats had higher lipid hydroperoxide (HP) and lower superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) serum activities than C and Cu-10 rats. LH was increased and GSH-Px was decreased, while no alterations were observed in SOD and catalase in serum of DCu-60 animals. DCu-60 rats had increased urinary glucose, creatinine and albumin. In conclusion, Cu intake at high concentration induced adverse effects on lipid profile, associated with oxidative stress and diminished activities of antioxidant enzymes. Diabetic animals were more susceptible to copper toxicity. High Cu intake induced dyslipidemic profile, oxidative stress and kidney dysfunction in diabetic condition. Copper renal toxicity was associated with oxidative stress and reduction at least, one of the antioxidant enzymes. (C) 2004 Elsevier Ltd. All rights reserved.

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.

Morphological biomarkers in the Rhinocricus padbergi midgut exposed to contaminated soil

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