Avaliação radiográfica, densitométrica e histológica do uso de perfurações ósseas para o estímulo de consolidação de fraturas do terço distal do rádio de cães

To stimulate the bone callus development process from distal third of radius, 24 adult mongrel dogs used were from both sexes. These dogs were separated in two experimental groups of 12 animals each, named control and treated, divided in 4 moments (M1=15 days; M2=30 days; M3=45 days; M4=60 days), who underwent were performed surgical fractures. In treated group, it was performed bone perforations on proximal and distal edges, craniolateral and mediolateral to the fracture site. At the end of each moment, control and treated animals were evaluated by radiography, histology, and bone mineral densitometry (BMD) was determined on fracture site. According to the radiographic data of treated dogs, it was verified on days 15 and 30 more intense bone regeneration than control group. During M3 and M4, it wasn't detected any difference in bone reparation process betweencontrol and treated groups. In densitometric study, BMD values were greater in treated animals than in control dogs. Histological studies revealed at 15 and 30 days chondrocyte hyperplasia and initial endochondral ossification on drilled limbs; control group showed sustainment connective tissue and initial chondrocyte hiperplasia. At M3 and M4 of the treated group, were verified development and remodeling of periosteal callus in more advanced phases when comparing with limbs from control group. It can be concluded that using perforations enhances blood flow supply and activation of osteogenic cells on fracture site, stimulating the beginning of fracture consolidation process.

Complete denture wearing and fractures among edentulous patients treated in university clinics

Objective: The prevalence of wearing and fracture of complete dentures was evaluated among edentulous patients treated in two dental schools in Brazil. Background: Acceptance and wearing of complete dentures are related to adaptive behaviour of edentulous patients. However, one reason that could interfere with the wearing dentures is their potential to fracture, which is still a common complication in denture rehabilitation practice. Material and methods: Two hundred and twenty-four edentulous patients rehabilitated with complete dentures from 2000 to 2005 in Araçatuba and Araraquara Dental School, University of State of São Paulo, were assessed in 2006 and 2007 to answer a questionnaire about wearing and fracture of their dentures. Statistical analysis were performed using Epi Info software and chi-squared test to compare maxillary and mandibular data (α = 0.05). Results: Almost 26% of the patients did not wear their dentures, and among the remainder, the majority wore the maxillary denture. About 30% of the dentures were fractured, with higher prevalence in the maxillary arch (p = 0.003). Conclusions: Discontinuation of wearing dentures was quite high, especially considering the treatment which was carried out in university clinics. Prevalence of fractures was also high, greater for the maxillary denture, and was one of the main reasons for non-wearing of complete dentures. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

Prospective study of postoperative sensory disturbances after surgical treatment of mandibular fractures

Introduction: This present study's purpose is to evaluate the degree of paresthesia and recovery of inferior alveolar nerve in patients with mandible fractures who underwent surgical treatment. Material and methods: Nineteen patients were evaluated (27 hemimandibles) at six different times: preoperative (T1), postoperative 1 week (T2), postoperative 1 month (T3), postoperative 3 months (T4), postoperative 6 months (T5), and postoperative 1 year (T6). Subjective and objective methods were used for this evaluation. Results: The results were analyzed using likelihood ratio chi-square test for the hypothesis of no association between indicators of sensitivity and responses to the questionnaire, and the Cochran-Mantel-Haenszel test for equality hypothesis. All objective tests showed a statistically significant worsening in sensitivity at T2 (p < 0. 0001) and a significant improvement after T4 (α < 0. 05). The subjective tests showed an association with the objectives tests, and improvement in sensitivity after T4 (p < 0. 0001) was noted. Discussion: The first postoperative week is the period in which there are major changes with respect to sensitivity, and after 3 months postoperatively, the recovery reaches its apex with little difference observed after this period. In this research 100 % of the patients analyzed recovered all sensibility until T6. © 2012 Springer-Verlag.

Analysis of the lightning attractive radius of power transmission lines through the use of a physically-oriented model

Models of different degrees of complexity are found in the literature for the estimation of lightning striking distances and attractive radius of objects and structures. However, besides the oversimplifications of the physical nature of the lightning discharge on which most of them are based, till recently the tridimensional structure configuration could not be considered. This is an important limitation, as edges and other details of the object affect the electric field and, consequently, the upward leader initiation. Within this context, the Self-consistent leader initiation and propagation model (SLIM) proposed by Becerra and Cooray is state-of-the-art leader inception and propagation leader model based on the physics of leader discharges which enables the tridimensional geometry of the structure to be taken into account. In this paper, the model is used for estimating the striking distance and attractive radius of power transmission lines. The results are compared with those obtained from the electrogeometric and Eriksson's models. © 2003-2012 IEEE.

Fraturas de rádio e ulna em cães no período de janeiro de 2001 a dezembro de 2011

Pós-graduação em Cirurgia Veterinária - FCAV

Influência das proteínas morfogenéticas ósseas adsorvidas à hidroxiapatita e aglutinantes do colágeno bovino na consolidação da fratura do rádio em coelhos

Pós-graduação em Medicina Veterinária - FMVZ

Expressão dos fatores de crescimento obtidos do plasma rico em plaquetas, no tratamento de fraturas experimentais do radio de cães

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

Implante de tecido prostático do cão na ostectomia parcial do rádio em coelhos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Finite element evaluation of three methods of stable fixation of condyle base fractures

The surgical treatment of mandibular condyle fractures currently offers several possibilities for stable internal fixation. In this study, a finite element model evaluation was performed of three different methods for osteosynthesis of low subcondylar fractures: (1) two four-hole straight plates, (2) one seven-hole lambda plate, and (3) one four-hole trapezoidal plate. The finite element model evaluation considered a load applied to the first molar on the contralateral side to the fracture. Results showed that, although the three methods are capable of withstanding functional loading, the lambda plate displayed a more homogeneous stress distribution for both osteosynthesis material and bone and may be a better method when single-plate fixation is the option.

Biomechanical Study in Polyurethane Mandibles of Different Metal Plates and Internal Fixation Techniques, Employed in Mandibular Angle Fractures

The aim of this study was to perform a physicochemical and morphological characterization and compare the mechanical behavior of an experimental Ti-Mo alloy to the analogous metallic Ti-based fixation system, for mandibular angle fractures. Twenty-eight polyurethane mandibles were uniformly sectioned on the left angle. These were divided into 4 groups: group Eng 1P, one 2.0-mm plate and 4 screws 6 mm long; group Eng 2P, two 2.0-mm plates, the first fixed with 4 screws 6 mm long and the second with 4 screws 12 mm long. The same groups were created for the Ti-15Mo alloy. Each group was subjected to linear vertical loading at the first molar on the plated side in a mechanical testing unit. Means and standard deviations were compared with respect to statistical significance using ANOVA. The chemical composition of the Ti-15Mo alloy was close to the nominal value. The mapping of Mo and Ti showed a homogeneous distribution. SEM of the screw revealed machining debris. For the plates, only the cpTi plate undergoes a surface treatment. The metallographic analysis reveals granular microstructure, from the thermomechanical trials. A statistically significant difference was found (P < 0.05) when the comparison between both internal fixation techniques was performed. The 2P technique showed better mechanical behavior than 1P.

Measurement of the ratio of inclusive jet cross sections using the anti-k(T) algorithm with radius parameters R=0.5 and 0.7 in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Spontaneous healing responses detected by cone-beam computed tomography of horizontal root fractures: a report of two cases

Horizontal root fractures (HRF) usually affect the anterior teeth as a result of trauma, and generally heal spontaneously, depending on the vitality of the pulp. Diagnosis based on clinical findings, sensitivity tests, and radiographic examination is important to determine the presence of a root fracture and to prevent a root fracture from passing unnoticed. Cone-beam computed tomography (CBCT) has been used successfully for diagnosis and prognosis imaging of root fractures and has proved to be superior to other radiographic methods. This study reports two cases of dental trauma caused by a collision and a sports accident. The patients suffered horizontal root fractures in the maxillary left central incisor and in the mandibular left central incisor. The diagnosis of root fracture was confirmed by cone-beam computed tomography (CBCT) images, which also demonstrated spontaneous healing of the fracture line. The repair occurred by interposition of connective tissue in the former case and by interposition of bone and connective tissue in the latter case. The final diagnoses of both cases were based on CBCT images, indicating the importance of a CBCT examination to reach a firm diagnosis and to follow the healing process of root fracture cases, avoiding unnecessary radical endodontic treatment.

Treatment and complications of orbito-zygomatic fractures

The aim of the present study was to analyze the etiology, type and treatment employed in the orbito-zygomatic fractures (OZ). Also, postoperative complications are described and correlated with the type of treatment used. Fifty patients with OZ fractures were evaluated. Orbital fractures in which the zygomatic bone was not involved were excluded. Epidemiologic data and characteristics of treatment such as the type of material used for osteosynthesis, number of anatomical sites on which rigid internal fixation (RIF) was applied, surgical approaches and associated complications were recorded. The main causes of trauma were motorcycle and bicycle accidents, constituting 52% of the sample. The osteosynthesis system used was the 2.0 mm, except in four patients in whom the 1.5mm system was used for fixation at the infra-orbital rim. A total of 18% of the patients required reconstruction of the internal orbit and in all cases titanium mesh was used. 46% of the patients received RIF in three anatomical sites, most in the fronto-zygomatic suture, infra-orbital rim and zygomatic-maxillary buttress. The most frequent complication was paresthesia of the infra-orbital nerve (34 patients, 68%). Other findings were also discussed with the intent of better understanding the treatment of the OZ fractures.

A six-year retrospective study of maxillofacial fractures from radiographic findings in Brazil

Objective: this study aimed to present the causes and prevalence of maxillofacial fractures that occurred in the region of Araraquara-SP – Brazil, during a 6-year period. Methods: information regarding age, gender, etiology, and maxillofacial fracture site, as well as type of radiographic examination were evaluated. Data were gathered from the radiographic examination and radiographic report of the Division of Dentomaxillofacial Radiology, and from charts of the Division of Oral and Maxillofacial Surgery of patients attending for maxillofacial fractures from 2004 to 2009. A descriptive statistical analysis was developed using Epi-Info 3.5.1. Results: from a total of 11,728 patients assisted, 407 patients presented maxillofacial fractures. The prevalent age ranged from 21 to 30 years old. From the total patients, 322 were men and 85 were women (ratio of men to women was 3.8:1). Panoramic radiography (n = 306) was most frequently used to observe maxillofacial fractures. Mandibular fractures were frequent in the body of the mandible (n = 127), followed by symphysis (n = 102), and the prevalent cause was traffic accidents (n = 161). Conclusion: more than half of affected individuals were younger than 40 years of age. The body of the mandible was the most common fracture location visualized by panoramic radiography for traffic accidents and fights.

Intraoral approach for treatment of displaced condylar fractures: case report

Dislocated subcondylar fractures often require open reduction and internal fixation. This treatment modality results in better anatomy, early function, and facilitated physical therapy. Ideal stable fixation is obtained by use of two miniplates to control the tension zone in the sigmoid notch area and stabilize the posterior border region or, if there is not enough space, one stronger plate. That is most frequently achieved through extraoral approaches. Recently new instruments have facilitated the use of an intraoral approach, which is used usually with the aid of an endoscope. However, it is possible to perform the procedure without the endoscope if proper instruments and clinical mirrors for checking the posterior border reduction and fixation are used. A case of reduction and fixation of a medially dislocated condylar fracture is presented and discussed.