Puricelli biconvex arthroplasty: an experimental study in sheep.

BACKGROUND: The aim of this study was to establish a sheep model of the Puricelli biconvex arthroplasty (ABiP) technique in sheep for evaluating its functional, biological and histological parameters. METHODS: Ten Corriedale black sheep were submitted to TMJ total reconstruction with poly(methyl methacrylate) (PMMA) using ABiP and euthanized after 45 (n = 5) or 90 (n = 5) days. Control animals (n = 2) underwent sham operations and were euthanized after 45 days. Variables were assessed before the surgery (T0), immediately after (T1) and at 45 or 90 postoperative days (T2). RESULTS: Histological analyses showed regression of inflammatory cells over the follow-up period. PMMA showed reduced porosity and roughness in the articular contact area. PMMA temporal components showed linear and volumetric wear in comparison to control, but no foreign body reaction was observed. The reconstructions were stable in all animals. The amplitude of mouth opening and left lateral movements were maintained, except for a reduction in the range of right lateral movements at day 90 in the experimental group. Clinical, macroscopic and radiographic observations showed that the reconstructions were stable. CONCLUSIONS: The analysis of functional, biological and histological parameters in sheep submitted to ABiP showed stable results of the procedure, with maintenance of body weight and all mandibular movements, save contralateral mandibular movement, suggesting that joint function was completely maintained following the procedure. This experimental study provides support for clinical results previously reported of the ABiP technique in TMJ reconstruction procedures.

Astroglial Alterations in the Hippocampus of Rats Submitted to a Single Trans-Cranial Direct Current Stimulation Trial.

Evidence indicates that transcranial direct current stimulation (tDCS) provides therapeutic benefits in different situations, such as epilepsy, depression, inflammatory and neuropathic pain. Despite the increasing use of tDCS, its cellular and molecular basis remains unknown. Astrocytes display a close functional and structural relationship with neurons and have been identified as mediators of neuroprotection in tDCS. Considering the importance of hippocampal glutamatergic neurotransmission in nociceptive pathways, we decided to investigate short-term changes in the hippocampal astrocytes of rats subjected to tDCS, evaluating specific cellular markers (GFAP and S100B), as well as markers of astroglial activity; glutamate uptake, glutamine synthesis by glutamine synthetase (GS) and glutathione content. Data clearly show that a single session of tDCS increases the pain threshold elicited by mechanical and thermal stimuli, as evaluated by von Frey and hot plate tests, respectively. These changes involve inflammatory and astroglial neurochemical changes in the hippocampus, based on specific changes in cell markers, such as S100B and GS. Alterations in S100B were also observed in the cerebrospinal fluid of tDCS animals and, most importantly, specific functional changes (increased glutamate uptake and increased GS activity) were detected in hippocampal astrocytes. These findings contribute to a better understanding of tDCS as a therapeutic strategy for nervous disorders and reinforce the importance of astrocytes as therapeutic targets.

Abordagem interdisciplinar no tratamento da macroglossia na síndrome de Beckwith-Wiedemann: relato de caso / Interdisciplinary approach in the treatment of macroglossia in Beckwith-Wiedemann syndrome: case report

RESUMO O objetivo deste estudo foi relatar a abordagem interdisciplinar no manejo da macroglossia em um caso de paciente com síndrome de Beckwith-Wiedemann, no período de dez anos. O acompanhamento iniciou pela equipe de Cirurgia Bucomaxilofacial, seguido da Fonoaudiologia, em função de dificuldades alimentares. Após avaliação clínica e instrumental, aos 8 meses de idade, iniciou-se a intervenção fonoaudiológica com foco na disfagia orofaríngea e na terapia miofuncional orofacial. Foi verificado, com 1 ano e 11 meses, ausência de sinais de alteração de deglutição em fase faríngea e melhora na postura de lábios e língua. Aos 3 anos, foram iniciados estímulos para retirada dos hábitos orais e o treino da função mastigatória. O tratamento ortodôntico para correção de mordida aberta anterior e mordida cruzada posterior unilateral iniciou-se aos 6 anos. Aos 7 anos e 5 meses de idade, constatou-se estabilidade do modo respiratório nasal e adequação da postura de repouso de lábios e língua. Aos 9 anos, em função de recidiva das alterações oclusais, optou-se pela redução cirúrgica da língua seguida de terapia miofuncional orofacial, retomada aos 9 anos e 3 meses. O resultado foi a correção da postura da língua na deglutição e a adequação da fala. A associação dos tratamentos, envolvendo Fonoaudiologia, Ortodontia e Cirurgia Bucomaxilofacial foi considerada efetiva no manejo da macroglossia, resultando na adequação e equilíbrio das funções orofaciais.

ABSTRACT This study aims to report the interdisciplinary management of macroglossia in a Beckwith-Wiedemann syndrome patient during ten years. Clinical follow-up started by the Oral and Maxillofacial Surgery team, followed by Speech Therapy due to feeding difficulties. After clinical and instrumental evaluation, at 8 months old, the speech therapy intervention was indicated, focusing on oropharyngeal dysphagia and orofacial myofunctional therapy. At 1 year and 11 months, no signs of swallowing alteration in the pharyngeal phase and improvement in the posture of the lips and tongue were found. At the age of 3, stimulation to remove oral habits and train masticatory function were initiated. Orthodontic treatment to correct anterior open bite and unilateral posterior crossbite started at age 6. At 7 years and 5 months, there was stability in the nasal breathing mode and adequacy of resting posture of lips and tongue. At the age of 9, due to relapse of the occlusal alterations, surgical reduction of the tongue was indicated, followed by orofacial myofunctional therapy, restarted at the age of 9 years and 3 months. The result was the correction of the posture of the tongue during swallowing and speech adequacy. The association of treatments involving Speech Therapy, Orthodontics and Oral and Maxillofacial Surgery was considered effective in the management of the macroglossia. It resulted in the adequacy and equilibrium of orofacial functions.

Puricelli biconvex arthroplasty as an alternative for temporomandibular joint reconstruction: description of the technique and long-term case report.

BACKGROUND: There are several indications for partial or total replacement of the temporomandibular joint (TMJ), including neoplasms and severe bone resorptions. In this regard, several techniques have been suggested to increase the functionality and longevity of these prosthetic devices. This case report describes the treatment of a TMJ ankylosis patient with the Puricelli biconvex arthroplasty (ABiP) technique, with a long-term follow-up. CASE PRESENTATION: In 1978, a 33-year-old male polytraumatised patient developed painful symptoms in the right preauricular region, associated with restricted movement of the ipsilateral TMJ. Due to subcondylar fracture, an elastic maxillomandibular immobilisation (EMMI) was applied. Subsequently, the patient was referred for treatment when limitations of the interincisal opening (10 mm) and the presence of spontaneous pain that increased on palpation were confirmed. Imaging exams confirmed the fracture, with anteromedial displacement and bony ankylosis of the joint. Exeresis of the compromised tissues and their replacement through ABiP was indicated. The method uses conservative access (i.e., preauricular incision), partial resection of the ankylosed mass, and tissue replacement using two poly(methyl methacrylate) components, with minimal and stable contact between the convex surfaces. At the end of the procedure, joint stability and dental occlusion were tested. The patient showed significant improvement at the postoperative 6-month follow-up, with no pain and increased mouth opening range (30 mm). At the 43-year follow-up, no joint noises, pain or movement restrictions were reported (mouth opening of 36 mm). Imaging exams did not indicate tissue degeneration and showed the integrity of prosthetic components. CONCLUSIONS: The present case report indicates that ABiP enables joint movements of the TMJ, allowing the remission of signs and symptoms over more than 40 years of follow-up. These data suggest that this technique is a simple and effective alternative when there is an indication for TMJ reconstruction in adult patients with ankylosis.

Evaluation of the immediate effects of a single transcranial direct current stimulation session on astrocyte activation, inflammatory response, and pain threshold in naïve rats.

Transcranial direct current stimulation (tDCS) has demonstrated clinical benefits such as analgesia, anti-inflammatory, and neuroprotective effects. However, the mechanisms of action of a single tDCS session are poorly characterized. The present study aimed to evaluate the effects of a single tDCS session on pain sensitivity, inflammatory parameters, and astrocyte activity in naive rats. In the first experiment, sixty-day-old male Wistar rats (n = 95) were tested for mechanical pain threshold (von Frey test). Afterward, animals were submitted to a single bimodal tDCS (0.5 mA, 20 min) or sham-tDCS session. According to the group, animals were re-tested at different time intervals (30, 60, 120 min, or 24 h) after the intervention, euthanized, and the cerebral cortex collected for biochemical analysis. A second experiment (n = 16) was performed using a similar protocol to test the hypotheses that S100B levels in the cerebrospinal fluid (CSF) are altered by tDCS. Elisa assay quantified the levels of tumor necrosis factor-alfa (TNF-α), interleukin-10 (IL10), S100 calcium-binding protein B (S100B), and Glial fibrillary acidic protein (GFAP). Data were analyzed using ANOVA and independent t-test (P < 0.05). Results showed that tDCS decreased pain sensitivity (30 and 60 min), cerebral TNF-α and S100B levels (30 min). CSF S100B levels increased 30 min after intervention. There were no differences in IL10 and GFAP levels. TCDS showed analgesic, anti-inflammatory, and neuroprotective effects in naive animals. Therefore, this non-invasive and inexpensive therapy may potentially be a preemptive alternative to reduce pain, inflammation, and neurodegeneration in situations where patients will undergo medical procedures (e.g., surgery).

Thirty-eight-year follow-up of the first patient of mandibular reconstruction with free vascularized fibula flap.

BACKGROUND: The mandible is responsible for vital functions of the stomatognathic system, and its loss results in functional and aesthetic impairment. Mandibular reconstruction with free fibula flap is considered the gold standard for mandibular reconstruction. CASE PRESENTATION: We describe here the 38-year follow-up of the patient who was the first case of mandibular reconstruction with free fibula flap reported in the literature. The original report describes a 27-year-old woman who had undergone extensive mandibulectomy due to an osteosarcoma. A microvascularized fibula flap was used for mandibular reconstruction in 1983. Two years later, a vestibulo-lingual sulcoplasty with skin graft was performed to allow the construction of a total dental prosthesis. Fifteen years after the initial treatment, an autologous iliac crest graft was placed in the fibula flap, aimed at increasing bone thickness and height for rehabilitation with implant supported prosthesis. In 2015, a rib graft was positioned in the mental region, enhancing the support to the soft tissues of the face and improving the oral function. A recent review of the patient shows well-balanced facial morphology and optimal functional results of the procedure. CONCLUSIONS: The fibula flap method, described in 1975 and first reported for mandibular reconstruction in 1985, continues to be applied as originally described, especially where soft tissue damage is not extensive. Its use in reconstructive surgery was expanded by advancements in surgery and techniques such as virtual surgical planning. However, there is still a lack of evidence related to the long-term evaluation of outcomes. The present work represents the longest-term follow-up of a patient undergoing mandibular reconstruction with free vascularized fibula flap, presenting results showing that, even after 38 years, the procedure continues to provide excellent results.

Apicotomia associada ao tracionamento ortocirúrgico em dente com dilaceração radicular / Apicotomy associated with orto-surgical treatment in tooth with a root dilaceration

Introdução: A apicotomia é uma técnica, que vem sendo utilizada em dentes com dilaceração radicular acentuada, com o intuito de liberar a porção do dente impactada e, dessa forma, permitir seu reposicionamento na arcada dentária. Este trabalho tem como objetivo apresentar um relato de caso clínico do manejo ortocirúrgico de tracionamento ortodôntico associado à apicotomia em dente incluso com dilaceração radicular acentuada. Relato de caso: O paciente foi encaminhado para o serviço de bucomaxilofacial para exodontia do elemento incluso após insucesso de tracionamento ortocirúrgico, em que se verificou, ao exame radiográfico periapical, dente incluso com dispositivo ortodôntico e dilaceração radicular importante. Diante disso, realizou-se, sob anestesia local, a apicotomia e instalação do dispositivo ortodôntico. O paciente evoluiu bem, e, após 8 meses, o elemento dentário encontrava-se em posição oclusal e em função mastigatória. Considerações finais: Assim, a técnica da apicotomia mostra-se eficaz como alternativa ao insucesso do tracionamento ortodôntico tradicional, sendo uma técnica mais conservadora que a exodontia, necessitando de conhecimento teórico e domínio técnico do profissional... (AU)

Introduction: Apichotomy is a technique that has been used in teeth with severe root laceration in order to release the impacted tooth portion and thus allow its repositioning of the tooth in the dental arch. The aim of this paper is to present a clinical case report of orthosurgical orthodontic traction management associated with apichotomy in an included tooth with severe root laceration. Case report: The patient was referred to the Oral and Maxillofacial Service for extraction of the included element after ortho-surgical traction failure, which was verified by periapical radiographic examination, tooth included with orthodontic device and significant root laceration. Thus, under local anesthesia, apichotomy and orthodontic device installation were performed. The patient progressed well, and after 8 months the dental element was in occlusal position and in masticatory function. Final considerations: Thus, the apichotomy technique is effective as an alternative to the failure of traditional orthodontic traction, being a more conservative technique than extraction and requiring theoretical knowledge and technical mastery of the Professional... (AU)

Reduction of osteoarthritis severity in the temporomandibular joint of rabbits treated with chondroitin sulfate and glucosamine.

Osteoarthritis is a degenerative disease that causes substantial changes in joint tissues, such as cartilage degeneration and subchondral bone sclerosis. Chondroitin sulfate and glucosamine are commonly used products for the symptomatic treatment of osteoarthritis. The aim of the present study was to investigate the effects of these products when used as structure-modifying drugs on the progression of osteoarthritis in the rabbit temporomandibular joint. Thirty-six New Zealand rabbits were divided into 3 groups (n = 12/group): control (no disease); osteoarthritis (disease induction); and treatment (disease induction and administration of chondroitin sulfate and glucosamine). Osteoarthritis was induced by intra-articular injection of monosodium iodoacetate. Animals were killed at 30 and 90 days after initiation of therapy. The treatment was effective in reducing disease severity, with late effects and changes in the concentration of glycosaminoglycans in the articular disc. The results indicate that chondroitin sulfate and glucosamine may have a structure-modifying effect on the tissues of rabbit temporomandibular joints altered by osteoarthritis.

Condylotomy to Reverse Temporomandibular Joint Osteoarthritis in Rabbits.

PURPOSE: Osteoarthritis (OA) of the temporomandibular joint (TMJ) is characterized by local tissue degeneration and pain. Treatments have been aimed at reducing symptoms, and only some can interfere with the progression of pathophysiologic changes caused by OA. Condylotomy is an alternative treatment for patients with OA refractory to conventional treatment. The aim of the present animal study was to investigate the influence of condylotomy on TMJ OA in New Zealand rabbits. MATERIALS AND METHODS: The 36 rabbits were divided into 3 groups: the osteoarthritis group (OG; induced OA), treatment group (TG; induced OA plus condylotomy), and control group (CG; neither OA nor surgery). OA was induced using intra-articular monosodium iodoacetate injection for 40 days. The rabbits in the TG underwent condylotomy and were killed 20, 40, and 60 days after treatment. The rabbits in the CG and OG were killed at the same points. RESULTS: The articular joint condition was better in the TG 60 days after surgery (P = .032). A direct comparison revealed regression of TMJ OA over time among the treated rabbits (P = .008). Surgical treatment promoted mandibular condylar remodeling in the TG, reversing the tissue degeneration caused by OA. CONCLUSIONS: Our findings suggest that condylotomy could be an option for the treatment of OA and prevent damage to TMJ structures. This could be of particular importance for patients without satisfactory responses to more conservative treatment.

Dental consultation requests to oral and maxillofacial surgery in a hospital in Brazil

Introduction: This study analyzed dental consultation requests to the division of oral and maxillofacial surgery in a Brazilian tertiary hospital. Methods: A cross-sectional study with data collected retrospectively from inpatients' electronic medical records containing dental consultation requests made between January 2013 and December 2017. Results: 327 consultation requests were analyzed. Mean (SD) patient age was 38.71 (24.4) years; 164 (50.2%) were male and 267 (81.7%) were Caucasian. Regarding systemic conditions, 34 (10.4%) were classified as ASA I, 86 (26.3%) as ASA II, 182 (55.7%) as ASA III, and 25 (7.6%) as ASA IV. Dental consultations were mostly requested by the internal medicine team (n = 42, 12.8%). The most common reason for consultation was septic teeth (n = 131, 40.1%). Complementary tests were required in 188 (57.5%) cases. Surgical intervention was required in 82 (25.0%), with tooth extraction as the most prevalent procedure (20.2%). The most demanding service was inpatient care, with 276 (84.4%) requests. Cases were resolved in 249 (76.1%). Conclusions: The division of oral and maxillofacial surgery in our hospital deals with a great amount of consultations, contributing with surgical procedures to the adequacy of patients' oral health with a high effectiveness rate. Our data illustrate the contribution of dentists in a hospital setting, assisting the medical team in providing comprehensive care for inpatients. (AU)

Nitrogen-containing bisphosphonate therapy-Part II: Assessment of alveolar bone tissue inflammatory response in rats-A blind randomized controlled trial.

This study aimed to evaluate the alveolar bone tissue inflammatory response in rats undergoing zoledronic acid therapy. The study sample was composed of 28 Wistar rats. Animals from the test group GTa received a weekly intraperitoneal dose of 0.2 mg/kg of zoledronic acid for 3 weeks, while test group GTb received the same dose for 8 weeks. A physiological saline dose, equivalent to that of the medication, was administered to the controls in groups GCa and GCb. A defect was created in the dental crown of the lower first molars using a drill to simulate pulp and periapical injury. Data were evaluated regarding image grey levels by cone-beam computed tomography and histologically by assigning scores for the presence of inflammatory infiltrate, type of infiltrate, vascularization, bone necrosis and dental resorption. Grey levels in the 3-week therapy group (GTa) showed more pronounced changes in comparison with those seen in the GCa group (P < 0.05). Evaluation of the scores demonstrated no association between any of the variables amongst the groups (>0.05). However, bone remodelling decreased in the groups receiving the medication. Bone necrosis was present more frequently in group GTb than in the control group GCb. The results suggest that the drug interfered in the reaction capacity of the alveolar bone tissue as test group GTa showed higher grey levels in comparison to the control group GCa. In addition, there was less bone remodelling activity, with the appearance of bone necrosis zones and intense acute inflammatory infiltrate associated with the 8-week therapy group GTb.

Occurrence of dermoid cyst in the floor of the mouth: the importance of differential diagnosis in pediatric patients.

Lesions in the floor of the mouth can be a challenging diagnosis due to the variety of pathological conditions that might be found in this area. Within a broad range of lesions, attention has to be addressed to those that require specific management, such as a dermoid cyst (DC) and a ranula. Especially in pediatric patients, in whom the failure of diagnosis can postpone the correct treatment and cause sequelae later in life. DC, a developmental anomaly, is managed primarily by surgical resection. On the other hand, ranula is a pseudocyst that may be treated by marsupialization. This article reports a large and painful lesion in the floor of the mouth in a pediatric patient. With a diagnostic hypothesis of ranula, two surgical interventions were performed, but there were recurrences of the lesion. Subsequently, the patient was referred to the Oral and Maxillofacial Surgery Unit for re-evaluation. Computed tomography showed a semi-transparent image suggesting a cystic formation. Another surgical procedure was performed where the lesion was completely removed. Anatomopathological analysis confirmed the diagnosis of DC. The five-year follow-up showed no signs of recurrence. This article indicates that although DC in the floor of the mouth is rare, it should be considered in the differential diagnosis of other diseases in this area. This precaution may be particularly important in the following circumstances: 1) Similar lesions that have different therapeutic approaches and, 2) To prevent future sequelae in pediatric patients.

Occurrence of dermoid cyst in the floor of the mouth: the importance of differential diagnosis in pediatric patients

Abstract Lesions in the floor of the mouth can be a challenging diagnosis due to the variety of pathological conditions that might be found in this area. Within a broad range of lesions, attention has to be addressed to those that require specific management, such as a dermoid cyst (DC) and a ranula. Especially in pediatric patients, in whom the failure of diagnosis can postpone the correct treatment and cause sequelae later in life. DC, a developmental anomaly, is managed primarily by surgical resection. On the other hand, ranula is a pseudocyst that may be treated by marsupialization. This article reports a large and painful lesion in the floor of the mouth in a pediatric patient. With a diagnostic hypothesis of ranula, two surgical interventions were performed, but there were recurrences of the lesion. Subsequently, the patient was referred to the Oral and Maxillofacial Surgery Unit for re-evaluation. Computed tomography showed a semi-transparent image suggesting a cystic formation. Another surgical procedure was performed where the lesion was completely removed. Anatomopathological analysis confirmed the diagnosis of DC. The five-year follow-up showed no signs of recurrence. This article indicates that although DC in the floor of the mouth is rare, it should be considered in the differential diagnosis of other diseases in this area. This precaution may be particularly important in the following circumstances: 1) Similar lesions that have different therapeutic approaches and, 2) To prevent future sequelae in pediatric patients.

Repair of bone defects using adipose-derived stem cells combined with alpha-tricalcium phosphate and gelatin sponge scaffolds in a rat model.

OBJECTIVES: This study aimed to evaluate the potential of adipose-derived stem cells (ASCs) combined with a modified α-tricalcium phosphate (α-TCP) or gelatin sponge (GS) scaffolds for bone healing in a rat model. MATERIAL AND METHODS: Bone defects were surgically created in the femur of adult SHR rats and filled with the scaffolds, empty or combined with ASCs. The results were analyzed by histology and histomorphometry on days seven, 14, 30, and 60. RESULTS: Significantly increased bone repair was observed on days seven and 60 in animals treated with α-TCP/ASCs, and on day 14 in the group treated with GS/ASCs, when compared with the groups treated with the biomaterials alone. Intense fibroplasia was observed in the group treated with GS alone, on days 14 and 30. CONCLUSIONS: Our results showed that the use of ASCs combined with α-TCP or GS scaffolds resulted in increased bone repair. The higher efficacy of the α-TCP scaffold suggests osteoconductive property that results in a biological support to the cells, whereas the GS scaffold functions just as a carrier. These results confirm the potential of ASCs in accelerating bone repair in in vivo experimental rat models. These results suggest a new alternative for treating bone defects.

Repair of bone defects using adipose-derived stem cells combined with alpha-tricalcium phosphate and gelatin sponge scaffolds in a rat model

Abstract Objectives This study aimed to evaluate the potential of adipose-derived stem cells (ASCs) combined with a modified α-tricalcium phosphate (α-TCP) or gelatin sponge (GS) scaffolds for bone healing in a rat model. Material and Methods Bone defects were surgically created in the femur of adult SHR rats and filled with the scaffolds, empty or combined with ASCs. The results were analyzed by histology and histomorphometry on days seven, 14, 30, and 60. Results Significantly increased bone repair was observed on days seven and 60 in animals treated with α-TCP/ASCs, and on day 14 in the group treated with GS/ASCs, when compared with the groups treated with the biomaterials alone. Intense fibroplasia was observed in the group treated with GS alone, on days 14 and 30. Conclusions Our results showed that the use of ASCs combined with α-TCP or GS scaffolds resulted in increased bone repair. The higher efficacy of the α-TCP scaffold suggests osteoconductive property that results in a biological support to the cells, whereas the GS scaffold functions just as a carrier. These results confirm the potential of ASCs in accelerating bone repair in in vivo experimental rat models. These results suggest a new alternative for treating bone defects.

Influence of a Magnetic Field and Laser Therapy on the Quality of Mandibular Bone During Distraction Osteogenesis in Rabbits.

PURPOSE: This study evaluated the use of low-level laser therapy (LLLT) and exposure to a magnetic field (MF) during distraction osteogenesis. MATERIALS AND METHODS: The sample consisted of 18 rabbits divided into 3 groups of 6 animals each: control, MF exposure (briefly, magnetized gold-coated washers were placed next to the distractor device), and LLLT exposure (830 nm applied every 48 hours over 4 points [dose, 5 J/cm2] during the consolidation period). The same distraction osteogenesis protocol was used in all 3 groups (0.5 mm every 12 hours for 1 week). RESULTS: Quantitative microscopic analysis of sections stained with hematoxylin and eosin showed a statistically significant difference in the amount of newly formed bone in the MF group compared with the LLLT group (P = .006). The number of cells with more than 3 argyrophilic nucleolar organizer regions also was significantly different between the LLLT and control groups (P = .038). CONCLUSION: Distraction osteogenesis effectively promoted bone lengthening. The LLLT group exhibited a larger amount of newly formed bone and a larger number of osteoblasts in the cell division phase, but the difference was not statistically relevant compared with the control group.

Efeito do ácido peracético sobre a adesão microbiana e as propriedades de tubos endotraqueais

Objetivo: avaliar a influência do número de imersões em ácido peracético na colonização bacteriana, na composição química, na rugosidade e na capacidade de recuperação após a deformação de tubos endotraqueais. Materiais e método: quatro tubos foram sub-metidos a sucessivas imersões em ácido peracético, constituindo quatro grupos: um controle (esterilizado pelo fabricante) e outros submetidos a uma, duas ou três imersões, de forma a simular o reprocessamento dos tubos. Os ensaios realizados foram: espectroscopia de infravermelho, rugosidade superficial, deformação da luz do tubo após compressão e colonização por Staphylococcus aureus. Resultados: o número de imersões (reprocessamento) não influenciou a colonização dos tubos por Staphylococcus aureus (p = 0,235), nem a composição química, nem a rugosidade (p = 0,621). Além disso, não houve diferença na capacidade do tubo em recuperar-se após deformação (p = 0,633). Conclusão: o reprocessamento por até três vezes não traz prejuízo às propriedades do material e não aumenta a colonização bacteriana na superfície dos tubos.

Effects of a buried magnetic field on cranial bone reconstruction in rats.

The understanding of bone repair phenomena is a fundamental part of dentistry and maxillofacial surgery. Objective The present study aimed to evaluate the influence of buried magnetic field stimulation on bone repair in rat calvaria after reconstruction with autogenous bone grafts, synthetic powdered hydroxyapatite, or allogeneic cartilage grafts, with or without exposure to magnetic stimulation. Material and Methods Ninety male Wistar rats were divided into 18 groups of five animals each. Critical bone defects were created in the rats' calvaria and immediately reconstructed with autogenous bone, powdered synthetic hydroxyapatite or allogeneic cartilage. Magnetic implants were also placed in half the animals. Rats were euthanized for analysis at 15, 30, and 60 postoperative days. Histomorphometric analyses of the quantity of bone repair were performed at all times. Results These analyses showed significant group by postoperative time interactions (p=0.008). Among the rats subjected to autogenous bone reconstruction, those exposed to magnetic stimulation had higher bone fill percentages than those without magnetic implants. Results also showed that the quality of bone repair remained higher in the former group as compared to the latter at 60 postoperative days. Conclusions After 60 postoperative days, bone repair was greater in the group treated with autogenous bone grafts and exposed to a magnetic field, and bone repair was most pronounced in animals treated with autogenous bone grafts, followed by those treated with powdered synthetic hydroxyapatite and allogeneic cartilage grafts.

Effects of a buried magnetic field on cranial bone reconstruction in rats

ABSTRACT The understanding of bone repair phenomena is a fundamental part of dentistry and maxillofacial surgery. Objective The present study aimed to evaluate the influence of buried magnetic field stimulation on bone repair in rat calvaria after reconstruction with autogenous bone grafts, synthetic powdered hydroxyapatite, or allogeneic cartilage grafts, with or without exposure to magnetic stimulation. Material and Methods Ninety male Wistar rats were divided into 18 groups of five animals each. Critical bone defects were created in the rats’ calvaria and immediately reconstructed with autogenous bone, powdered synthetic hydroxyapatite or allogeneic cartilage. Magnetic implants were also placed in half the animals. Rats were euthanized for analysis at 15, 30, and 60 postoperative days. Histomorphometric analyses of the quantity of bone repair were performed at all times. Results These analyses showed significant group by postoperative time interactions (p=0.008). Among the rats subjected to autogenous bone reconstruction, those exposed to magnetic stimulation had higher bone fill percentages than those without magnetic implants. Results also showed that the quality of bone repair remained higher in the former group as compared to the latter at 60 postoperative days. Conclusions After 60 postoperative days, bone repair was greater in the group treated with autogenous bone grafts and exposed to a magnetic field, and bone repair was most pronounced in animals treated with autogenous bone grafts, followed by those treated with powdered synthetic hydroxyapatite and allogeneic cartilage grafts.

Rabbit model for osteoarthrosis of the temporomandibular joint as a basis for assessment of outcomes after intervention.

Osteoarthritis can be induced in the temporomandibular joint (TMJ) by primary or secondary trauma, or overloading of the joint. We have therefore systematically evaluated the histological progression of experimental osteoarthritis induced by a high concentration of monosodium iodoacetate into the rabbit TMJ. These findings may contribute to the establishment of a protocol to investigate the benefits of treatment of osteoarthritis of the TMJ. We used 21 male New Zealand rabbits; the 15 in the test group were given an intra-articular injection of monosodium iodoacetate 10mg/ml into the right TMJ and were killed after 60 (n=5), 80 (n=5), and 100 days (n=5). The six in the control group were given an injection of saline into the right TMJ. The assessment system for osteoarthritis based on six grades was used for the histological analysis of severity. The model was effective in producing histological changes in the cartilage consistent with those found in osteoarthritis at all time points. The within-group analysis indicated that the disease did not progress after 60 days. The successful induction of osteoarthritis in this way, its stabilisation after 60 days, and the appropriate size of the animal suggest that this experimental model is ideal for future studies of the effectiveness of treatment in osteoarthritis of the TMJ.