Sexual dimorphism in the mandible in a Portugese population - Predicting the gender for forensic purpose: a pilot study / Dimorfismo sexual mandibular da população Portuguesa ­ Predição do gênero para análise forense: um estudo piloto

Este estudo teve como objetivo avaliar o dimorfismo sexual em uma coleção de mandíbulas portuguesas através de uma metodologia métrica digital, utilizando análise estatística descritiva, inferencial e multivariada para identificar quais parâmetros são mais dimórficos e quais são os melhores preditores de sexo. Trinta e três mandíbulas (14 mulheres e 19 homens) e pertences pessoais foram fotograficamente registrados com código e sexo. Os dados foram coletados por tomografia e as medidas foram feitas pelo software Simplant Pro. Foram registrados a largura máxima e mínima do ramo mandibular, altura condilar, altura do processo coronoide, altura da sínfise mandibular, ângulo mandibular, distâncias bimentual, biantegonial, bigonial e bicondilar e comprimento máximo mandibular. A análise estatística foi realizada utilizando IBM® SPSS. Os resultados mostraram diferenças estatisticamente significativas para os seguintes parâmetros: altura do processo coronoide, altura do côndilo, comprimento máximo da mandíbula e largura mínima do ramo mandibular. Na análise estatística multivariada foi possível identificar a altura do processo coronoide como melhor preditor de sexo com precisão em 72,2% dos casos. Isto permite uma diferenciação mais fácil entre mandíbulas femininas e masculinas com uma precisão de 64,3% e 78,9%, respectivamente. Foi possível concluir que a altura do processo coronoide é o parâmetro mais dimórfico e o melhor preditor de sexo na amostra.

This study aimed to assess sex dimorphism in a collection of Portuguese mandibles through a digital metric methodology by using descriptive, inferential, and multivariate statistical analysis to identify which parameters are the most dimorphic and which are the best sex predictors. Thirty-three mandibles (14 females and 19 males) and personal belongings were photographically registered with code and sex. Data was collected using tomography, and measurements were made using the Simplant Pro software. The maximum and minimum width of the mandibular ramus, condylar height, coronoid process height, mandibular symphysis height, mandibular angle, bi-mental, bi-antegonial, bi-gonial and bi-condylar distances, and maximal mandibular length were registered. Statistical analysis was performed using IBM® SPSS. The results showed statistically significant differences for the following parameters: coronoid process height, condyle height, the maximum length of the mandible, and the minimum width of the mandibular ramus. In the multivariate statistical analysis, it was possible to identify the coronoid process height as the best sex predictor accurately in 72.2% of cases. This allows for easier differentiation between female and male mandibles with an accuracy of 64.3% and 78.9%, respectively. It was possible to conclude that the coronoid process height is the most dimorphic parameter and the best sex predictor in the sample.

Surface roughness of three different glass ionomers with our without finishing/polishing: an in vitro study

Purpose: This study aimed to compare the surface roughness among 3 types of glass ionomers (GI) before (no polishing) and after polishing with three different materials. Methods: 20 discs for each GI group were obtained (A-Ionolux; B-IonoStar Plus; C-Ketac). Those groups were subdivided according to finishing and polishing: subgroups 1 (control) - no polishing, 2 - polishing with prophylactic brush and pumice paste, 3 - Enhance tips with water, and 4 - Sof-Lex system with Easy Glaze and polymerization. For each disc face, the total distance analyzed was 2.88cm (6x48mm). Then, the roughness was compared using the Kruskal-Wallis with Bonferroni test, with significant data if p<0.05. Results: The mean of roughness within Group A was lower for subgroup 4 (1.07±0.54 µm) and higher for subgroup 2 (2.33±1.17 µm). Within group B, B4 had the lowest mean of roughness (0.93±0.38 µm) and B2 (1.24 ± 0.78 µm) the highest roughness. Within group C, Group C4 had the lowest mean roughness value (0.84±0.54 µm), and C3 had the highest mean (2.48±1.05 µm). After polishing, subgroup 4 had the general lowest values for surface roughness (mean Ra 0.95), followed by subgroup 1 (Ra=1.27), subgroup 2 (Ra=1.89), and higher values for subgroup 3. All intragroup analysis for A, B, and C were statistically significant. Group A presented the highest roughness (p<0.05), and no statistically significant evidence existed between groups B and C (p>0.05). Conclusion: The reduction of the roughness of the materials is dependent on their composition and the polishing and finishing techniques applied.

Is the facial bone wall critical to achieving esthetic outcomes in immediate implant placement with immediate restoration? A systematic review.

BACKGROUND: Rehabilitation in the anterior region requires specific conditions for success, such as the presence of papilla, emergence profile, and balance between pink and white esthetic. OBJECTIVES: This systematic review aimed to evaluate the esthetic risk associated with immediate implant placement with immediate restoration in the anterior superior area, where the facial bone plate may be absent or deficient. MATERIAL AND METHODS: The search was done in PubMed, Embase, Cochrane, Lilacs, Scopus, Scielo, and Google Scholar databases. The investigation involved clinical studies and observational studies published between January 2012 and July 2023. Studies were excluded if there was less than 12-month follow-up, no immediate restoration or facial defect, heavy smokers, or systemic disease. The risk of bias was assessed using the ROBINS-I and Modified-Cochrane RoB tools. RESULTS: Twelve studies were included in this systematic review. The thinner the facial plate, the higher the alveolus's risk of gingival recession or shrinkage. There was an increased interproximal recession when the thin phenotype was associated with flap surgery. An increase in pink esthetic score (PES) was reached when immediate implant placement (IIP) and immediate restoration were done. Soft tissue augmentation achieved more gingival-level stability. Regardless of the initial phenotype, an esthetic outcome was delivered. The risk of bias was high in 1 study and moderate in 3 studies. CONCLUSION: It is possible to conclude that esthetic results and increased final PES or patient satisfaction index in IIP treatments associated with immediate restoration could be obtained even in buccal bone wall defects or gingival recession, regardless of their extension.

Gingival recession in canines orthodontically aligned: a narrative review / Recessão gengival em caninos ortodonticamente alinhados: uma revisão narrativa

Background: The orthodontic traction of impacted canines represents a great challenge for Orthodontics. Surgical exposure of the impacted canine and the complex orthodontic mechanics applied to align the tooth back to the arch can lead to complications involving supporting tissues inducing gingival recession when the teeth are moved out of the alveolar bone. Aim: The aim of this study is to present an updated bibliographic review of the main periodontal results found in the literature after the clinical management of impacted canines and the prevalence of gingival recession. Materials and methods: Research in electronic databases PubMed, PMC, and MedLine until June 2020 and reference lists of relevant publications were used to identify studies that assessed the periodontal status of impacted and orthodontically tractioned canines. Controlled and randomized clinical trials, literature reviews, systematic reviews, studies in humans, meta- analyzes and text that had at least one occurrence relating to gingival recession, periodontal outcomes and impacted canines tractioned orthodontically, whether by buccal or palatal, superior and / or lower as the eligibility criteria. Results: 691 articles were found in a free search. After applying the eligibility criteria, 7 relevant articles were subtracted, and these results were more frequent for upper canines. Conclusion: Currently, there is no clear evidence to determine which surgical technique procedure is better to discover canines in terms of periodontal outcomes. The results found stated that clinically the evidence were insignificant when compared to teeth normally erupted.

Introdução: O tracionamento ortodôntico de caninos inclusos representa um grande desafio para a Ortodontia. A exposição cirúrgica do canino impactado e a complexa mecânica ortodôntica aplicada para alinhar o dente de volta ao arco podem levar a complicações envolvendo os tecidos de suporte, induzindo recessão gengival quando os dentes são movimentados para fora do osso alveolar. Objetivo: O objetivo deste estudo foi apresentar uma revisão bibliográfica atualizada dos principais resultados periodontais encontrados na literatura após o manejo clínico de caninos impactados e a prevalência de recessão gengival. Materiais e métodos: Foram feitas pesquisas eletrônicas no PubMed, PMC e MedLine até junho de 2020 e uma listas de referência de publicações relevantes foram usadas para identificar estudos que avaliaram o estado periodontal de caninos impactados e tracionados ortodonticamente. Ensaios clínicos controlados e randomizados, revisões de literatura, revisões sistemáticas, estudos em humanos, metanálises e textos que tiveram pelo menos uma ocorrência relacionada a recessão gengival, desfechos periodontais e caninos impactados tracionados ortodonticamente, seja por vestibular ou palatino, foram os critérios de elegibilidade. Resultados: Foram encontrados 691 artigos em busca livre. Após a aplicação dos critérios de elegibilidade, 7 artigos relevantes foram subtraídos, sendo esses resultados mais frequentes para caninos superiores. Conclusão: Atualmente, não há evidências claras para determinar qual técnica cirúrgica é melhor para descobrir caninos em termos de resultados periodontais. Os resultados encontrados afirmaram que clinicamente as evidências foram insignificantes quando comparadas a dentes normalmente

Potential Impact of Prosthetic Biomaterials on the Periodontium: A Comprehensive Review.

The success of a prosthetic treatment is closely related to the periodontal health of the individual. The aim of this article was to review and present the importance of prosthetic restorative materials on the condition of the periodontium, the changes that occur in the composition of the subgingival microbiota and the levels of inflammatory markers in gingival crevicular fluid. Articles on the influence of different prosthetic restorative materials on subgingival microbiota and proinflammatory cytokines were searched for using the keywords "prosthetic biomaterials", "fixed prosthesis", "periodontal health", "subgingival microbiota", "periodontal biomarkers" and "gingival crevicular fluid" in PubMed/Medline, Science Direct, Scopus and Google Scholar. The type of material used for prosthesis fabrication together with poor marginal and internal fit can result in changes in the composition of the subgingival microbiota, as well as increased accumulation and retention of dentobacterial plaque, thus favoring the development of periodontal disease and prosthetic treatment failure. Biological markers have helped to understand the inflammatory response of different prosthetic materials on periodontal tissues with the main purpose of improving their clinical application in patients who need them. Metal-free ceramic prostheses induce a lower inflammatory response regardless of the fabrication method; however, the use of CAD/CAM systems is recommended for their fabrication. In addition, it is presumed that metal-ceramic prostheses cause changes in the composition of the subgingival microbiota producing a more dysbiotic biofilm with a higher prevalence of periodontopathogenic bacteria, which may further favor periodontal deterioration.

Evaluation of the occlusal contact area of molar dental implants comparing two different thicknesses (16 µm and 200 µm) of articulating occlusal papers and forces (200 and 250 N): a pivot in vitro study

Introduction: The goal of this pilot study was to evaluate the differences between checking occlusion on implants crowns using 16 or 200 µm thickness of articulating occlusal paper, and to compare the stained occlusal area between the groups after bite forces of 200 and 250 N. Methods: It was included 10 casts of articulated-type IV gypsum, 10 NiCr crowns, articulating occlusal papers (16 µm and 200 µm thick), and a compression test machine. Compressive forces (200 and 250 N.mm) were applied on models, to check the occlusal contact area of fixed and cemented crowns. The contact areas on the crowns were measured through images obtained by the scanning electron microscope. Statistical tests were performed considering the significant level of 5% (p≤0.05). Results: The stains found using 200 µm of articulating paper were higher than those with 16 µm, independent of the force applied. However, the stains obtained in lower teeth with different strengths (200 and 250N) marked with 16 µm articulating paper were not possible to score. The articulating paper variable had significant statistical results (p=0.002), while the variables force (p=0.443) and articulating paper-force interaction (p=0.607) were not significant. The mean area found in staining using the 200 µm and 16 µm papers was, respectively, 8.3380 mm2 and 3.4759 mm2. Conclusion: It was possible to confirm that 200 µm of articulating occlusal paper showed better and significant results to stain the occlusal area, permitting a more accurate adjustment independent of the force applied.

Facial Hemiplegia Treated with Botulinum Toxin: A Case Report.

Facial hemiplegia happens when the seventh cranial nerve is inflamed, causing a dysfunction of the facial nerve in specific regions. This case report brings a complex case of facial hemiplegia, a non-temporary lesion caused by a traumatic accident, which had a more conservative approach, treating the patient with botulinum toxin. After explanation of treatment outcomes, the patient favored treatment on a unilateral side with botulinum toxin applied locally to the muscles. It was applied on her left side, in order to change the muscles tonus and improve the esthetic. The patient adhered to immediate and short-term instructions following the procedure, including movement limitation and skin exposure avoidance. At 2 weeks, the patient returned to follow-up, and the result was checked. After around 6-month follow-up, the patient was reassessed, and a new application was done. The patient tried to contract the procerus and corrugator muscles which were treated, and periorbicular region that was corrected. After contracting the frontal muscle, a satisfactory result was also seen in the frontal area. While limited to a single case presentation, botulinum toxin may be an effective short-term tool for treatment of facial hemiplegia to establish an effective esthetic result.

The Influence of rhBMP-7 Associated with Nanometric Hydroxyapatite Coatings Titanium Implant on the Osseointegration: A Pre-Clinical Study.

Background: Bioceramic nanometer coatings have been regarded as potential substitutes for plasma-sprayed hydroxyapatite coatings, and the association with bone morphogenetic protein (BMP) is an attempt to achieve faster osseointegration to hasten oral rehabilitation. Objective: This study aimed to investigate the effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) on the osseointegration of titanium implants coated with a thin film surface of hydroxyapatite (HA). Methods: Two implants (n = 24) were placed in each white New Zealand rabbits' femur (n = 6). Implants were placed in the right femur after standard instrumentation (A and B) and in the left femur after an over-instrumentation (C and D), preventing bone-implant contact. The distal implants were installed associated with rhBMP-7 (groups B [regular instrumentation] and D [over-instrumentation]) and, also, in the absence of without BMP (control groups A [regular instrumentation] and C [over-instrumentation]). After 4 weeks, the animals were euthanized. The bone blocks containing the implants were embedded in methyl methacrylate and sectioned parallel to the long axis of the implant, which were analyzed by image segmentation. The data were analyzed using a nonparametric statistical method. Results: We observed that Group A had a mean bone formation of 35.6% compared to Group B, which had 48.6% (p > 0.05). Moreover, this group showed 28.3% of connective tissue compared to Group A, with 39.3%. In the over-instrumented groups, rhBMP-7 (Group D) showed an enhanced and significant increase in bone formation when compared with the group without rhBMP-7 (Group C). Conclusion: We concluded that the association of rhBMP-7 to thin nanostructure HA-coated implants promoted greater new bone area than the same implants in the absence of rhBMP-7, mainly in cases of over-instrumented implant sites.

Endoscopic analysis of alterations in sinus floor elevation approaching the summers technique and immediate implant: a clinical trial with 10 years follow-up / Análise endoscópica das alterações na elevação do assoalho do seio maxilar com abordagem da técnica de Summer e implante imediato: um ensaio clínico com 10 anos de acompanhamento

The goal of this study was to evaluate by endoscopy, possible intercurrences during the sinus floor lifting employing the Summers technique, besides verify the implants' survival rate after 10 years. Six patients (12 sinus) were included in this study. The same surgeon performed the procedures, under local anesthesia and venous sedation in the hospital. All participants underwent sinus lift and implant placement in only one procedure, as previously planned, using endoscopic analysis (Stortz®). All cases received bovine bone graft (Bio-Oss®) before the implant placement. After 10 years, the patients were recalled for follow-up. Two intercurrences (16.66%) were detected using the endoscope, one simple rupture, and another perforation with the leaking of the graft within the sinus. Both were reverted and corrected immediately. There was one implant loss (8.33%), therefore this patient did not undergo any intercurrence in transoperative, and the membrane was elevated lesser than 5 mm. The survival rate reached was 91.66%. The osteotome technique constitutes a reliable method with a long-term of 10 years presenting a high implant survival rate, suggesting an elevation up to 5.5 mm in healthy patients. The occurrences in transoperative were only detected by the endoscopic analysis which must be stimulated to guarantee more secure visibility. Otherwise, the association the atraumatic technique and endoscope was tough, increased the costs, limiting the use routinely.

O objetivo deste estudo foi avaliar através de endoscopia as possíveis intercorrências durante levantamento de seio maxilar fechado, além de verificar a taxa de sobrevivência dos implantes após 10 anos. Seis pacientes (12 seios maxilares) foram incluídos neste estudo com idades entre 26 e 74 anos. O mesmo cirurgião realizou os procedimentos, sob anestesia local e sedação venosa em ambiente hospitalar. Todos os participantes foram submetidos à elevação do seio nasal e colocação do implante em apenas um procedimento, conforme planejado anteriormente, por acompanhamento transcirúrgico da endoscopia (Stortz®). Todos os casos receberam enxerto ósseo bovino (Bio-Oss®) antes da colocação do implante. Após 10 anos, os pacientes foram chamados para acompanhamento. Foram detectadas duas intercorrências (16,66%) com o endoscópio, uma ruptura simples e outra perfuração com extravasamento do enxerto para dentro do seio. Ambos foram revertidos e corrigidos imediatamente. Houve perda de um implante (8,33%), portanto esse paciente não apresentou intercorrência no transoperatório e a membrana estava elevada menos de 5 mm. A taxa de sobrevivência alcançada foi de 91,66%. A técnica do osteótomo constitui um método confiável em longo prazo (10 anos) apresentando uma alta taxa de sobrevivência do implante, sugerindo que uma elevação de até 5,5 mm em pacientes saudáveis é possível. Assim, verificou-se que as ocorrências no transoperatório foram detectadas apenas pela análise endoscópica que deve ser estimulada para garantir uma visibilidade mais segura. Por outro lado, a associação da técnica fechada com o endoscópio foi difícil, aumentou os custos, limitando seu uso como rotina

Clinical evaluation and biological understanding of the early step-by-step healing after periodontal microsurgery: A case report with PES analysis comparing initial and 31-day result.

Microsurgery has evolved, permitting faster vascularization and healing than macro-interventions, reducing tissue trauma and obtaining precise wound closure. Therefore, this study aimed to detail the initial healing steps after the periodontal microsurgical procedure. A -26 year-old female had a localized recession (anterior lower tooth, recession type1-), with the absence of local keratinized tissue width (KTW) and adjacent gingival thickness (GT)<1 mm. After oral prophylaxis and occlusal adjustments, the pink esthetic score was performed (5 points), followed by the microsurgery procedure. Prior to inserting the subepithelial connective tissue graft (SCTG), the epithelial layer was removed, and the root surface was biomodified. Two days postoperatively, it was possible to observe a white layer from the SCTG in the gingival margin, decreasing after 4 days. In 6 days, the sutures were removed; no graft and volume loss was observed. For 9 days, the volume was the maintenance. Nevertheless, there was a reduction in tissue volume in the facial zone. After 11 and 13 days, an improved healing process was found, whereas, after 16 days, it was possible to report stable tissues, which was confirmed after 31 days, with a significant GR reduction and an increase in KTW and GT. Moreover, the final pink esthetic score (PES) was 9. Microsurgery had a faster healing and predictable outcome, suggesting reduced trauma, which may allow a quicker suture removal without jeopardizing the outcomes.

Gingival recession treatment with enamel matrix derivative associated with coronally advanced flap and subepithelial connective tissue graft: a split-mouth randomized controlled clinical trial with molecular evaluation.

OBJECTIVES: The goal of this study was to evaluate the impact of enamel matrix derivative (EMD) on periodontal healing after root coverage (RC) surgery, involving CAF in combination with SCTG, and to assess the molecular profile, verifying the inflammation level in early stage (1 and 2 weeks). MATERIALS AND METHODS: Thirty-two recessions (RT1) were submitted to periodontal surgery with (test) or without (control) EMD. The clinical parameters analyzed on the day of surgery and 6 months after the surgical procedure were as follows: recession height and width, keratinized tissue height, percentual root coverage, and the gingival thickness of keratinized tissue. Moreover, the main inflammatory biomarkers and growth factors (IL-1ß, IL-6, IL-8, FGF, MIP-1α and ß, PDGF, TNF-α, and VEGF) were evaluated at baseline, 7, and 14 days after procedures. RESULTS: The average root coverage was significantly higher in the test group as compared to the control group (86% vs. 66%, p = 0.008). The test side had significantly lesser final RH compared to the control side (p = 0.01). Also, there was a significant reduction of RW in both groups, with more significant results in the test group. KTH and GT were not significantly different at any time and group. After 14 days, the immunological analysis showed an increase of VEGF (p = 0.03) on the test group compared to the control side. CONCLUSION: The use of EMD in RC surgeries resulted in a significantly higher RC, as well as a significant increase in VEGF expression, suggesting that EMD may contribute to the angiogenic and healing process. CLINICAL RELEVANCE: EMD provided better results in root coverage treatment when associated with CAF and SCTG, beyond a greater releasing of angiogenic growth factor (VEGF), which enhanced the result.

Endodontic and Periodontal Treatment of Complete Buccal Root and Apex Exposition: A Challenging Case Report With 17 Months Follow-Up.

INTRODUCTION: This case report demonstrated a challenging clinical case addressed within a multidisciplinary approach to achieve its maintenance, even though had a poor prognosis. It was associated with the endodontic treatment with mucogingival techniques, including periodontal microsurgery and connective tissue graft. CASE PRESENTATION: A patient presented a deep gingival recession with the apex-exposed non-vital tooth with interproximal bone loss (RT2) and without mobility. The treatment involved an initial endodontic approach and periodontal therapy (scaling and root planing), microsurgical techniques with coronally advanced flap, root preparation with PrefGel (24% EDTA), enamel matrix derivatives (Emdogain), and connective tissue graft. As a clinical result, it was verified an increase of keratinized tissue width and gingival thickness, and root coverage (RC), reaching good esthetics and a stable result after 17 months. CONCLUSION: The correct diagnosis and technique selection may affect directly the outcome, especially in challenging cases. Even though there was a poor prognosis, an adequate treatment plan, patient cooperation, and technique mastery help to achieve a high level of RC, esthetic recovering, and successful outcome.

The influence of Aloe vera with mesenchymal stem cells from dental pulp on bone regeneration: characterization and treatment of non-critical defects of the tibia in rats.

OBJECTIVE: This study aimed to evaluate the inflammatory effect and bone formation in sterile surgical failures after implantation of a collagen sponge with mesenchymal stem cells from human dental pulp (hDPSCs) and Aloe vera. MATERIAL AND METHODS: Rattus norvegicus (n=75) were divided into five experimental groups according to treatment: G1) control (blood clot); G2) Hemospon®; G3) Hemospon® in a culture medium enriched with 8% Aloe vera; G4) Hemospon® in a culture medium containing hDPSCs and G5) Hemospon® in a culture medium enriched with 8% Aloe vera and hDPSCs. On days 7, 15 and 30, the animals were euthanized, and the tibia was dissected for histological, immunohistochemistry and immunofluorescence analyses. The results were analyzed using nonparametric Kruskal-Wallis test and Dunn's post-test. RESULTS: On days 7 and 15, the groups with Aloe vera had less average acute inflammatory infiltrate compared to the control group and the group with Hemospon® (p<0.05). No statistically significant difference was found between the groups regarding bone formation at the three experimental points in time. Osteopontin expression corroborated the intensity of bone formation. Fluorescence microscopy revealed positive labeling with Q-Tracker® in hDPSCs before transplantation and tissue repair. CONCLUSION: The results suggest that the combination of Hemospon®, Aloe vera and hDPSCs is a form of clinical treatment for the repair of non-critical bone defects that reduces the inflammatory cascade's effects.

Calcium silicate as a graft material for bone fractures: a systematic review.

Objective The goal of this review was to determine whether calcium silicate (wollastonite) as a bone graft material is a viable alternative to autogenous bone or whether the evidence base for its use is weak. Methods In this systematic review, electronic databases (MEDLINE/PubMed and BVS) were searched for relevant articles in indexed journals. Articles published in a 10-year period were identified (n = 48). After initial selection, 17 articles were assessed for eligibility; subsequently, seven articles were excluded and 10 articles were included. Results Among the studies included, 20% emphasized the importance of randomization, which adds reliability to the study, minimizing the risk of bias. High variability was observed in the material used, such as additives, amounts, dosage, and chemical alterations, rendering direct comparison among these studies impossible. The experimental periods varied considerably; one of the studies did not include statistical analysis, weakening the evaluation. Nonetheless, the true potential of wollastonite as a graft material conducive to new bone formation was reported in all studies. Conclusion The results support the use of wollastonite as a bone graft material. The initial research question was answered despite the significant variability observed among these preclinical studies, which hindered the precision of this analysis.

Entendendo os mecanismos moleculares envolvidos com a adesão de osteoblastos: possível envolvimento da proteína tirosina fosfatase de baixa massa molecular / Understanding the molecular mechanisms involved in osteoblast adhesion: possible involvement of protein tyrosine phosphatase low molecular

A interação das células com seu ambiente externo provoca modulação de diferentes vias de sinalização em cascata, que culmina em uma resposta específica. Este mecanismo de transdução de sinal é regido predominantemente por mecanismos transientes de fosforilização e desfosforilização em resíduos de tirosina (Y), executados por quinases (PTK) e fosfatases (PTP), respectivamente. Com a finalidade de conhecer os mecanismos de transdução de sinais envolvidos com a adesão de osteoblastos, nosso grupo de pesquisa tem estudado o envolvimento de diferentes proteínas e proposto um mecanismo global deste evento biológico... A despeito de sua expressão permanecer inalterada nos 2 períodos de análise, sugerimos em testes funcionais que LMWPTP era capaz de controlar ambas fosforilações em Y (416 e 397). Estes testes se basearam nas abordagens de silenciamento e super-expressão de LMWPTP, com posterior análise dos níveis de fosforilações por immunoblotting. Além disso, avaliamos a atividade de catalase e superóxido dismutase nestes períodos e verificamos que ambas estavam com atividade aumentada no período de 2 horas, sugerindo controle da quantidade de ROS. Juntos, esses dados sugerem que ROS é capaz de modular a fosforilação de FAK e Src através do controle direto da atividade de LMWPTP. Além disso, sugerimos que durante a adesão de osteoblastos há uma interação supra-molecular de FAK/Src/LMWPTP, formando um complexo capaz de controlar respostas transientes e imediatas via ativação de integrinas durante estes eventos.

Histomorfometria do tecido ósseo em ratas castradas tratadas com tibolona / Bone tissue histomorphometry in castrated rats treated with tibolone

INTRODUÇÃO E OBJETIVO: O efeito da tibolona utilizada em alta dose e por tempo prolongado foi analisado mediante estudo histomorfométrico de tíbias e fêmures de ratas castradas. MÉTODOS: O experimento utilizou 20 ratas Wistar, com peso médio de 250 g. Os animais foram distribuídos aleatoriamente em três grupos: ooforectomizado recebendo tibolona (OVX + T) (n = 9), ooforectomizado (OVX) (n = 6) e grupo controle não ooforectomizado (C) (n = 5). Deu-se início ao protocolo experimental 30 dias após a ooforectomia, perdurando por 20 semanas, com administração de tibolona (1 mg/dia) a OVX + T e carboximetilcelulose a OVX. O grupo C não foi submetido a qualquer tratamento. Tíbias e fêmures direitos foram fixados em formol a 10 por cento tamponado, descalcificados e processados para inclusão em parafina. Os cortes histológicos foram corados mediante hematoxilina-eosina para análise histomorfométrica. Mediram-se a espessura cortical e a cavidade medular em cortes transversais de tíbia e fêmur e percentual de porosidade e densidade trabecular em cortes longitudinais de fêmur. RESULTADO E DISCUSSÃO: Não houve diferença estatística entre OVX e OVX + T nas diversas análises. Os resultados demonstram que a tibolona não melhorou de forma significativa a qualidade óssea, porém preservou a massa óssea cortical, nas diáfises femoral e tibial, e o osso trabecular, nos côndilos femorais. O uso prolongado de tibolona em concomitância com alta dose pode ter influenciado tais efeitos, já que estudos recentes têm preconizado a utilização de doses mais baixas na prevenção da osteoporose. CONCLUSÃO: A ooforectomia ocasionou perda óssea nas regiões analisadas; a tibolona, apesar de não ter aumentado a massa óssea, manteve-a em níveis satisfatórios.

INTRODUCTION AND OBJECTIVE: The effect of tibolone administered in high dose over a prolonged period was analyzed through histomorphometry of tibia and femur samples from castrated rats. METHODS: The experiment was performed in 20 Wistar rats with average weight of 250 g. The animals were randomly divided into three groups: oophorectomized receiving tibolone (OVX + T) (n = 9), oophorectomized (OVX) (n = 6) and non-oophorectomized as control group (C) (n = 5). The experimental protocol was initiated 30 days after oophorectomy and lasted 20 weeks. Tibolone (1 mg/day) was administered to OVX + T rats and carboxymethyl cellulose to OVX. C rats did not go through any treatment. Right side tibias and femurs were fixed in 10 percent buffered formalin, decalcified and embedded in paraffin. Histological sections were stained by hematoxylin-eosin for histomorphometric analysis. The cortical thickness and medullary cavity were measured in transverse tibia and femur sections. The percentage of porosity and the trabecular density were determined in longitudinal femur sections. RESULTS AND DISCUSSION: There was no significant statistical difference between OVX and OVX + T in several analyses. The results showed that tibolone did not improve bone quality significantly, although it preserved cortical bone mass in femoral and tibial diaphyses and the trabecular bone in femoral condyles. The administration of tibolone in high dose for a prolonged period may have influenced these effects inasmuch as recent studies have recommended the use of lower doses in osteoporosis prevention. CONCLUSION: Oophorectomy caused bone loss in the analyzed regions. Despite the fact tibolone did not augment bone mass, this was kept at satisfactory levels.

Preservação alveolar com enxertos após exodontias e previamente à instalação de implantes / Alveolar preservation with bone graft after tooth extraction and previously to implant placement

A perda do dente ocasiona modificações locais crônicas, progressivas e cumulativas que repercutem no sistema estomatognático e também no aspecto social do paciente. Os avanços na Implantodontia permitem prevenir as alterações do complexo dentomucoalveolar através do preenchimento do alvéolo dentário imediatamente após a exodontia e previamente à instalação de implantes osseointegráveis. O procedimento representa, em algumas situações clínicas, uma técnica indispensável para a obtenção de um resultado estético satisfatório nas reabilitações protéticas. Para isso, o implantodontista deve conhecer as bases biológicas da regeneração óssea alveolar e suas indicações. Nesta revisão foram abordadas indicações, vantagens e tipos de biomateriais utilizados para preenchimento do alvéolo dentário imediatamente após a extração dentária sempre que o objetivo for a reabilitação através da instalação de implantes. Concluímos que biomateriais capazes de aliar osteocondução e osteoindução são desejáveis a fim de mimetizar os benefícios do osso autógeno, bem como é necessário investimento no planejamento e execução de estudos clínicos randomizados e duplo-cegos para a determinação da eficiência dos biomateriais para preenchimento de alvéolos dentários.