Role of the oblique ligament in the integrity of the medial collateral ligament of the canine elbow joint

Foram estudados o arranjo e o diâmetro médio das fibrilas colágenas do ligamento colateral medial da articulação do cotovelo do cão, isolado ou associado ao ligamento oblíquo e tracionado até a ruptura. Dezoito articulações foram divididas em três grupos. O primeiro grupo teve o ligamento colateral medial coletado, mas não tracionado; o segundo grupo teve o ligamento colateral medial tracionado isoladamente; o terceiro grupo teve os ligamentos colateral medial e oblíquo tracionados associadamente. O ligamento colateral medial não submetido ao ensaio de tração apresentou um padrão ondulado das fibras colágenas, o qual não foi totalmente destruído quando foi tracionado, associado ao ligamento oblíquo, e perdeu totalmente o padrão reticular das fibras colágenas quando testado isoladamente. Quando o ligamento colateral medial foi submetido à tensão isoladamente, o diâmetro médio das fibrilas colágenas aumentou em relação ao grupo não submetido à tensão. Associado ao ligamento oblíquo, o diâmetro médio das fibrilas colágenas foi o maior na região de inserção e o menor na região média, em relação aos outros grupos. Concluiu-se que o ligamento oblíquo pode favorecer a integridade da região de inserção do ligamento colateral medial, aumentando a eficácia de sua reconstrução após a lesão.

Study on the bone mineral density of broiler suffering femoral joint degenerative lesions

An experiment was carried out with male and females broilers of two different commercial breeds to evaluate bone mineral density of the right femur head. A number of 600 one-day-old broilers were raised in an experimental poultry house up to 42 days of age at the School of Veterinary Medicine and Animal Science of UNESP, Botucatu, Brazil. After slaughter, three males and three females in each breed in each of the established gross scores were selected. Their femora heads were submitted to gross examination, and subsequently the thighs were submitted to the Veterinary Hospital for radiographic analysis. Femora were also submitted to bone resistance, Seedor index, and dry matter content analyses. All these bone quality characteristics were different between males and females, independent of breed. Breeds presented similar behavior. It was possible to establish correlations between bone quality parameters, and confidence intervals for bone mineral density values, correlating them to femoral degeneration score, which allows characterizing femoral head lesions by radiographic optical densitometry.

Modeling and Experimental Aspects of Self-healing Bolted Joint through Shape Memory Alloy Actuators

Bolted joints are a form of mechanical coupling largely used in machinery due to their reliability and low cost. Failure of bolted joints can lead to catastrophic events, such as leaking, train derailments, aircraft crashes, etc. Most of these failures occur due to the reduction of the pre-load, induced by mechanical vibration or human errors in the assembly or maintenance process. This article investigates the application of shape memory alloy (SMA) washers as an actuator to increase the pre-load on loosened bolted joints. The application of SMA washer follows a structural health monitoring procedure to identify a damage (reduction in pre-load) occurrence. In this article, a thermo-mechanical model is presented to predict the final pre-load achieved using this kind of actuator, based on the heat input and SMA washer dimension. This model extends and improves on the previous model of Ghorashi and Inman [2004, "Shape Memory Alloy in Tension and Compression and its Application as Clamping Force Actuator in a Bolted Joint: Part 2 - Modeling," J. Intell. Mater. Syst. Struct., 15:589-600], by eliminating the pre-load term related to nut turning making the system more practical. This complete model is a powerful but complex tool to be used by designers. A novel modeling approach for self-healing bolted joints based on curve fitting of experimental data is presented. The article concludes with an experimental application that leads to a change in joint assembly to increase the system reliability, by removing the ceramic washer component. Further research topics are also suggested.

Radiographic measurement of tibial joint angles in sheep

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Radiographic Abnormalities in Barrel Racing Horses with Lameness Referable to the Metacarpophalangeal Joint

Barrel racing is one of the most popular uses of the American Quarter horse in North and South America. Although injury to the metacarpophalangeal joint frequently occurs in this sport, there is limited information describing the nature of these injuries. The aim of this study was to determine the most common radiographic abnormalities in barrel racing horses with lameness referable to the metacarpophalangeal joint. lameness examinations were performed on 63 barrel racing horses. Those found to be lame were subjected to radiographic examination. Lameness at trot was scored on a scale of 0-5 (0 = sound; 5 = inability to move). Data were analyzed using descriptive statistical analysis. of horses examined, 30 (47.6%) were lame with scores ranging from 1 to 4. Half of the lame horses (15 of 30) had grade 2 lameness of the right forelimb. Abnormal radiographic findings were more often present on the left forelimb and included signs of sesamoiditis (70%), villonodular synovitis (56.6%), osteoarthritis (36.6%), osteochondritis dissecans (13.3%), capsulitis (13.3%), and soft-tissue swelling (6.6%). Radiographic abnormalities indicated that sesamoiditis, villonodular synovitis, and osteoarthritis may be associated to mild-to-moderate lameness in barrel racing horses. Complementary sonographic evaluation is recommended to better characterize soft-tissue abnormalities. (C) 2012 Elsevier B.V. All rights reserved.

Origin of sensory and autonomic innervation of the rat temporomandibular joint: A retrograde axonal tracing study with the fluorescent dye fast blue

Previous studies that have used retrograde axonal tracers (horseradish peroxidase alone or conjugated with wheat germ agglutinin) have shown that the temporomandibular joint (TMJ) is supplied with nerve fibers originating mainly from the trigeminal ganglion, in addition to other sensory and sympathetic ganglia. The existence of nerve fibers in the TMJ originating from the trigeminal mesencephalic nucleus is unclear, and the possible innervation by parasympathetic nerve fibers has not been determined. In the present work, the retrograde axonal tracer, fast blue, was used to elucidate these questions and re-evaluated the literature data. The tracer was deposited in the supradiscal articular space of the rat TMJ, and an extensive morphometric analysis was performed of the labeled perikaryal profiles located in sensory and autonomic ganglia. This methodology permitted us to observe labeled small perikaryal profiles in the trigeminal ganglion, clustered mainly in the posterior-lateral region of the dorsal, medial and ventral thirds of horizontal sections, with some located in the anterior-lateral region of the ventral third. Sensory perikarya were also labeled in the dorsal root ganglia from C2 to C5. No labeled perikaryal profiles were found in the trigeminal mesencephalic nucleus. on the other hand, autonomic labeled perikaryal profiles were distributed in the sympathetic superior cervical and stellate ganglia, and parasympathetic otic ganglion. Our results confirmed those of previous studies and also demonstrated that: (i) there is a distribution pattern of labeled perikaryal profiles in the trigeminal ganglion; (ii) some perikaryal profiles located in the otic ganglion were labeled; and (iii) the trigeminal mesencephalic nucleus did not show any retrogradely labeled perikaryal profiles.

PAR(2) and Temporomandibular Joint Inflammation in the Rat

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

Putative antinociceptive action of nitric oxide in the caudal part of the spinal trigeminal nucleus during chronic carrageenan-induced arthritis in the rat temporomandibular joint

In order to investigate a putative role for nitric oxide (NO) in the central nociceptive processing following carrageenan-induced arthritis in the rat temporomandibular joint (TMJ), we analyzed the immunoreactivity, gene expression and activity of nitric oxide synthases (NOS) in the caudal part of the spinal trigeminal nucleus (Sp5C) during the acute (24 h), chronic (15 days) and chronic-active (14 days-24 h) arthritis. In addition, evaluation of head-withdrawal threshold was carried out in all phases of arthritis under chronic inhibition of nNOS with the selective inhibitor 7-nitroindazole (7-NI). Neurons with nNOS-like immunoreactivity (nNOS-LI) were concentrated mainly in the lamina II of the Sp5C, showing no significant statistical difference during arthritis. Only a discrete percentage of nNOS-LI neurons expressed Fos immunoreactivity. The mRNA expression for both nNOS and endothelial nitric oxide synthases (eNOS) presented no noticeable differences among the groups. No expression of inducible nitric oxide synthase (iNOS) was detected in the Sp5C by either immunohistochemistry or reverse-transcription polymerase chain reaction (RTPCR). Ca(2+)-dependent NOS activity in the ipsilateral Sp5C was significantly higher (108.3 +/- 49.2%; P<0.01) in animals during the chronic arthritis. Interestingly, this increased activity was completely abolished 24 h later, in the chronic-active arthritis. Finally, head-withdrawal threshold decreased significantly in the chronic arthritis in animals under 7-NI chronic inhibition. In conclusion, nNOS immunoreactivity and mRNA expression are stable in the Sp5C during TMJ arthritis evolution, but its activity significantly increases in the chronic-phases supporting an antinociceptive role of the nNOS as evidenced by pain threshold experiment. (C) 2009 Elsevier B.V. All rights reserved.

Phenotypic alterations of neuropeptide Y and calcitonin gene-related peptide-containing neurons innervating the rat temporomandibular joint during carrageenan-induced arthritis

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

Preload Evaluation of Different Screws in External Hexagon Joint

Purpose: This study compared the maintenance of tightening torque in different retention screw types of implant-supported crowns.Materials and Methods: Twelve metallic crowns in UCLA abutments cast with cobalt-chromium alloy were attached to external hexagon osseointegrated implants with different retention screws: group A: titanium alloy retention screw; group B: gold alloy retention screw with gold coating; group C: titanium alloy retention screw with diamond-like carbon film coating; and group D: titanium alloy retention screw with aluminum titanium nitride coating. Three detorque measurements were obtained after torque insertion in each replica. Data were evaluated by analysis of variance (ANOVA), Tukey's test (P < 0.05), and t test (P < 0.05).Results: Detorque value reduced in all groups (P < 0.05). Group A retained the highest percentage of torque in comparison with the other groups (P < 0.05). Groups B and D retained the lowest percentage of torque without statistically significant difference between them (P < 0.05).Conclusions: All screw types exhibited reduction in the detorque value. The titanium screw maintained the highest percentage of torque whereas the gold-coated screw and the titanium screw with aluminum titanium nitride coating retained the lowest percentage. (Implant Dent 2012;21:46-50)

Temporomandibular Joint Vibration Before and After Exercises and Occlusal Splints

Temporomandibular joint (TMJ) sounds are frequent in patients. The aim of this study was to analyze patients with clicking at the end of opening and at the beginning of closing their mouths treated by muscular exercises through chewing and by occlusal splints. Fifteen patients with clinically verified clicking and TMJ and 15 patients without sounds were selected by the Research Diagnostic Criteria for Temporomandibular Disorders. They were submitted to electrovibratography at consultation and 60 and 120 days of treatment by occlusal splints and exercises. Patients demonstrated significant reduction of TMJ sounds after treatment, but vibration intensity was not similar with that of the control group after 120 days.

Effect of Vertical Misfit on Screw Joint Stability of Implant-Supported Crowns

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

Maxillo-mandibular counter-clockwise rotation and mandibular advancement with TMJ Concepts (R) total joint prostheses Part IV - Soft tissue response

The purpose of this Study was to evaluate Soft tissue response to rnaxillo-mandibular counter-clockwise rotation, with TMJ reconstruction and mandibular advancement using TMJ Concepts (R) total joint prostheses, and maxillary osteotomies in 44 females. All patients were operated at Baylor University Medical Center, Dallas TX, USA, by one Surgeon (Wolford). Eighteen patients had genioplasties with either porous block hydroxyapatite or hard tissue replacement implants (Group 2) 26 had no genioplasty (Group 1). Surgically, the maxilla moved forward and upward by counter-clockwise maxillo-mandibular rotation with greater horizontal movement in Group 2. Vertically, both groups showed diversity of maxillo-mandibular mean movement. Group I showed a consistent 1:0.97 ratio of hard to soft tissue advancement at pogonion; Group 2 results were less consistent, with ratios between 1:0.84 and 1:1.02. Horizontal changes in upper lip morphology after maxillary advancement/impaction, VY closure, and alar base cinch sutures showed greater movement in both groups, than observed in hard tissue. Counter-clockwise rotation of the maxillo-mandibular complex using TMJ Concepts total joint prostheses resulted in similar soft tissue response as previously reported for traditional maxillo-mandibular advancement without counter-clockwise rotation of the occlusal plane. The association of chin implants, in the present sample, showed higher variability of soft tissue response.

Maxillo-mandibular counter-clockwise rotation and mandibular advancement with TMJ Concepts (R) total joint prostheses Part III - Pain and dysfunction outcomes

47 end-stage TMJ patients with high occlusal plane angulation, treated with TMJ custom-fitted total joint prostheses and simultaneous maxillo-mandibular counter-clockwise rotation were evaluated for pain and dysfunction presurgery (T1) and at the longest follow-up (T2). Patients subjectively rated their facial pain/headache, TMJ pain, jaw function, diet and disability. Objective functional changes were determined by measuring maximum interincisal opening (MIO) and laterotrusive movements. Patients were divided according to the number of previous failed TMJ surgeries: Group 1 (0-1), Group 2 (2 or more). Significant subjective pain and dysfunction improvements (37-52%) were observed (<0.001). MIO increased 14% but lateral excursion decreased 60%. The groups presented similar absolute changes, but Group 2 showed more dysfunction at T1 and T2. For patients who did not receive fat grafts around the prostheses and had previous failure of proplast/teflon and or silastic TMJ implants, more than half required surgery for TMJ debridement and removal of foreign body giant cell reaction and heterotopic bone formation. End-stage TMJ patients can be treated in one operation with TMJ custom-made total joint prostheses and maxillo-mandibular counter-clockwise rotation, for correction of dentofacial deformity and improvement in pain and TMJ dysfunction; Group 1 patients had better results than Group 2 patients.