Influence of bone marrow on osseointegration in long bones: an experimental study in sheep

Aim To evaluate the influence of yellow bone marrow on osseointegration of titanium oral implants using a long bone model.Material and methodsThe two tibiae of eight sheep were used as experimental sites. Two osteotomies for implant installation were prepared in each tibia. At the control sites, no further treatments were performed while, at the test sites, bone marrow was removed from the osteotomy site with a curette to an extent that exceeded the implant dimensions. As a result, the apical portion of the implants at the control sites was in contact with bone marrow while, at the test sites, it was in contact with the blood clot. After 2months, the same procedures were performed in the contralateral side. After another month, the animal was sacrificed. Ground sections were obtained for histological analysis.ResultsAfter 1month of healing, no differences between test and control sites were found in the apical extension of osseointegration and the percentage of new bone-to-implant contact. However, after 3months of healing, a higher percentage of new bone-to-implant contact was found at the test compared to the control sites in the marrow compartment. The apical extension of osseointegration, however, was similar to that found at the 1-month healing period both for test and control sites.ConclusionsOsseointegration appeared to be favored by the presence of a blood clot when compared to the presence of yellow fatty bone marrow. Moreover, the contact with cortical bone appeared to be a prerequisite for the osseointegration process in the long bone model.

Healing at implant sites prepared conventionally or by means of Sonosurgery (R): an experimental study in dogs

ObjectiveTo compare peri-implant tissue healing at implants installed in sites prepared with conventional drills or a sonic device.Material and methodsIn six Beagle dogs, the mandibular premolars and first molars were extracted bilaterally. After 3 months, full-thickness muco-periosteal flaps were elevated and recipient sites were prepared in both sides of the mandible. In the right side (control), the osteotomies were prepared using conventional drills, while, at the left side (test), a sonic device (Sonosurgery((R))) was used. Two implants were installed in each side of the mandible. After 8weeks of non-submerged healing, biopsies were harvested and ground sections prepared for histological evaluation.ResultsThe time consumed for the osteotomies at the test was more than double compared to the conventional control sites. No statistically significant differences were found for any of the histological variables evaluated for hard and soft tissue dimensions. Although not statistically significant, slightly higher mineralized bone-to-implant contact was found at the test (65.4%) compared to the control (58.1) sites.ConclusionsSimilar healing characteristics in osseointegration and marginal hard tissue remodeling resulted at implants installed into osteotomies prepared with conventional drills or with the sonic instrument (Sonosurgery((R))).

Sequential healing of the elevated sinus floor after applying autologous bone grafting: an experimental study in minipigs

AimTo describe the sequential healing after elevation of the maxillary sinus mucosa applying the lateral access technique with the use of autogenous bone grafting without membrane to occlude the osteotomy access.Material and methodsImmediately after the elevation of the maxillary sinus Schneiderian membrane, applying the lateral access technique in 10 minipigs, autologous bone was harvested from the lateral aspect of the mandibular molar region and ground into particles with a bone mill. The space under the Schneiderian membrane was filled with this graft. No membranes were placed onto the access osteotomy. The healing was evaluated after 15, 30, 90 and 180days. Paraffin sections were prepared and analyzed histologically.ResultsAfter 15days of healing, the elevated area was mainly filled with provisional matrix, newly formed bone and some remnants of bone chips, and appeared reduced in volume compared with that at the time of surgery. After 30days of healing, further shrinkage of the height of the elevated space was found, with similar percentages of the different tissue components. After 90 and 180days, the area underneath the Schneiderian membrane appeared reduced in volume and condensed toward the base of the sinus. The bone tissues appeared to be more mature, both for the mineralized and the non-mineralized portions, while connective tissue occupied 20% of the space, most likely related to the lack of the use of a membrane occluding the access at the time of surgery.ConclusionsSuboptimal healing outcomes with respect to augmentation of the space under the sinus floor membrane were documented when autologous bone chips were used as a filler and no membrane was applied to cover the access.

Surgical interventions for treating pectus excavatum

Background: Pectus excavatum is characterized by a depression of the anterior chest wall (sternum and lower costal cartilages) and is the most frequently occurring chest wall deformity. The prevalence ranges from 6.28 to 12 cases per 1000 around the world. Generally pectus excavatum is present at birth or is identified after a few weeks or months; however, sometimes it becomes evident only at puberty. The consequence of the condition on a individual's life is variable, some live a normal life and others have physical and psychological symptoms such as: precordial pain after exercises; impairments of pulmonary and cardiac function; shyness and social isolation. For many years, sub-perichondrial resection of the costal cartilages, with or without transverse cuneiform osteotomy of the sternum and placement of a substernal support, called conventional surgery, was the most accepted option for surgical repair of these patients. From 1997 a new surgical repair called, minimally invasive surgery, became available. This less invasive surgical option consists of the retrosternal placement of a curved metal bar, without resections of the costal cartilages or sternum osteotomy, and is performed by videothoracoscopy. However, many aspects that relate to the benefits and harms of both techniques have not been defined. Objectives: To evaluate the effectiveness and safety of the conventional surgery compared with minimally invasive surgery for treating people with pectus excavatum. Search methods: With the aim of increasing the sensitivity of the search strategy we used only terms related to the individual's condition (pectus excavatum); terms related to the interventions, outcomes and types of studies were not included. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, LILACS, and ICTPR. Additionally we searched yet reference lists of articles and conference proceedings. All searches were done without language restriction. Date of the most recent searches: 14 January 2014. Selection criteria: We considered randomized or quasi-randomized controlled trials that compared traditional surgery with minimally invasive surgery for treating pectus excavatum. Data collection and analysis: Two review authors independently assessed the eligibility of the trials identified and agreed trial eligibility after a consensus meeting. The authors also assessed the risk of bias of the eligible trials. Main results: Initially we located 4111 trials from the electronic searches and two further trials from other resources. All trials were added into reference management software and the duplicates were excluded, leaving 2517 studies. The titles and abstracts of these 2517 studies were independently analyzed by two authors and finally eight trials were selected for full text analysis, after which they were all excluded, as they did not fulfil the inclusion criteria. Authors' conclusions: There is no evidence from randomized controlled trials to conclude what is the best surgical option to treat people with pectus excavatum.

Maxillo-mandibular counter-clockwise rotation and mandibular advancement with TMJ Concepts (R) total joint prostheses Part I - Skeletal and dental stability

The purpose of this study was to evaluate skeletal and dental stability in patients who had temporomandibular joint (TMJ) reconstruction and mandibular counterclockwise advancement using TMJ Concepts total join, prostheses (TMJ Concepts Inc. Ventura, CA) with maxillary osteotomies being performed at the same operation. All patients were operated at Baylor University Medical Center, Dallas TX, USA, by one surgeon (Wolford). Forty-seven females were studied; the average post-surgical follow-up was 40.6 months. Lateral cephalograms were analyzed to estimate surgical and post-surgical changes. During surgery, the occlusal plane angle decreased 14.9 +/- 8.0 degrees. The maxilla moved forward and upward. The posterior nasal spine moved downward and forward. The mandible advanced 7.9 +/- 3.5 mm at the lower incisor tips, 12.4 +/- 5.4 mm at Point B, 17.3 +/- 7.0 mm at menton, 18.4 +/- 8.5 mm at pogonion, and 11.0 +/- 5.3 mm at gonion. Vertically, the lower incisors moved upward -2.9 +/- 4.0 mm. At the longest follow-up post surgery, the maxilla showed minor horizontal changes while all mandibular measurements remained stable. TMJ reconstruction and mandibular advancement with TMJ Concepts total joint prosthesis in conjunction with maxillary osteotomies for counter-clockwise rotation of the rnaxillo-mandibular complex was a stable procedure for these patients at the longest follow-up.

Analysis of residual stress and hardness in regions of pre-manufactured and manual bends in fixation plates for maxillary advancement

The aim of this study was to analyze, through Vickers hardness test and photoelasticity analysis, pre-bent areas, manually bent areas, and areas without bends of 10-mm advancement pre-bent titanium plates (Leibinger system). The work was divided into three groups: group I-region without bend, group II-region of 90° manual bend, and group III-region of 90° pre-fabricated bends. All the materials were evaluated through hardness analysis by the Vickers hardness test, stress analysis by residual images obtained in a polariscope, and photoelastic analysis by reflection during the manual bending. The data obtained from the hardness tests were statistically analyzed using ANOVA and Tukey's tests at a significance level of 5 %. The pre-bent plate (group III) showed hardness means statistically significantly higher (P < 0.05) than those of the other groups (I-region without bends, II-90° manually bent region). Through the study of photoelastic reflection, it was possible to identify that the stress gradually increased, reaching a pink color (1.81 δ / λ), as the bending was performed. A general analysis of the results showed that the bent plate region of pre-bent titanium presented the best results.

Sub-crestal positioning of implants results in higher bony crest resorption: an experimental study in dogs

To compare peri-implant soft- and hard-tissue integration at implants installed juxta- or sub-crestally. Furthermore, differences in the hard and soft peri-implant tissue dimensions at sites prepared with drills or sonic instruments were to be evaluated. Three months after tooth extraction in six dogs, recipient sites were prepared in both sides of the mandible using conventional drills or a sonic device (Sonosurgery(®) ). Two implants with a 1.7-mm high-polished neck were installed, one with the rough/smooth surface interface placed at the level of the buccal bony crest (control) and the second placed 1.3 mm deeper (test). After 8 weeks of non-submerged healing, biopsies were harvested and ground sections prepared for histological evaluation. The buccal distances between the abutment/fixture junction (AF) and the most coronal level of osseointegration (B) were 1.6 ± 0.6 and 2.4 ± 0.4 mm; between AF and the top of the bony crest (C), they were 1.4 ± 0.4 and 2.2 ± 0.2 mm at the test and control sites, respectively. The top of the peri-implant mucosa (PM) was located more coronally at the test (1.2 ± 0.6 mm) compared to the control sites (0.6 ± 0.5 mm). However, when the original position of the bony crest was taken into account, a higher bone loss and a more apical position of the peri-implant mucosa resulted at the test sites. The placement of implants into a sub-crestal location resulted in a higher vertical buccal bone resorption and a more apical position of the peri-implant mucosa in relation to the level of the bony crest at implant installation. Moreover, peri-implant hard-tissue dimensions were similar at sites prepared with either drills or Sonosurgery(®) .

Estudo da estabilidade da cirurgia do tipo sagital da mandíbula com vista a correção de deformidades faciais

This research evaluated the surgical stabilily in patients with mandibular prognathism and retrognathism in which was used sagital split technic to correct those detormities. Twelve patients were selected from the clinic of only one experienced surgeon. Six patients presenter a Class III 6 a Class II molar relationship. A comparative cefalometric analysis using linear and angular measurements was performed of pre-surgery, imediate pós-surgery and 1 year follow-up. The following conclusions were obtained. 1 The Dal Pont sagital split technic modified by Epker to correct mandibular prognathisn and retroghnatism is a stable technic and must be indicated to correct those deformities. 2 Small relapses are easily corrected by the post-surgical orthodontic treatment. 3 A small over correction is advised in cases of large mandibular advancements or set bascks. 4 In those cases which a large amount of mandibular retrusion on advancement need to be performed, a combination of maxillary and mandibular surgery should be used. Rigid fixation technic is also indicated in those cases

Expansão rápida de maxila assistida cirurgicamente por meio da piezocirurgia: relato de caso

Aim: the purpose of this study is to present a case of surgically assisted rapid maxillary expansion using piezosurgery and describe the benefits of using this device in this type of procedure. Case description: patient had adento-skeletal deformity Cl III with asevereatresia of jaw and underwent a rapid maxillary expansion and surgically assisted with the use of piezosurgery. Conclusion: the piezosurgerycan be used as an alternative in oral and maxillofacial surgery wich features provide greater accuracy and safety in surgery.

Anatomical description of arterial segment of spleen of deer

The anatomosurgical segmentation of the arteries of the spleen was studied in 31 deer of the species Mazama gouazoubira and Blastocerus dichotomus by means of vascular injection with latex and vinyl acetate and radiographic examination. The arteria lienalis penetrated through the hilus lienis in 87% of the cases, whereas an extrahilar artery was present in the other cases. An extraparenchymal division of the lineal artery into two, three or four segmental arteries was observed in 74% of the cases. Anastomoses between intraparenchymal arterial branches were rare and of a reduced calibre.

Avaliação Histológica e histomorfométrica do reparo ósseo em tíbias osteotomizadas de ratos (rattus novergicus albinus), submetidos a tratamento com ultrassom, frente à presença e ausência de carga

The response of bone metabolism is directly related to hormonal factors and mechanical stimuli that the bone is exposed. The ultrasonic energy on bone healing have been shown to be crucial for the stimulation and improvement in quality of newly formed tissue. The aim of this study was to analyze the action of low intensity ultrasound on bone healing of tibial osteotomy in rats subjected to tail suspension, through histological analysis and histomorphometry. Eighteen Rattus norvegicus albinos, Wistar, adults were divided into three groups, arranged as follows: G1 (n = 6), who remained free for a period of 15 days, G2 (n = 5), suspended by the tail for a period of 15 days and G3 (n = 7), suspended by the tail for a period of 36 days. In all three groups, both tibias were subjected to mono-cortical bone injury 4X2 mm in the medial region of the diaphysis, and the left limb was used as control and the right limb undergoing treatment with ultrasound (U.S.). The right tibia was treated with pulsed ultrasound at a frequency of 1.5 MHz, duty cycle 1:4, 30mW/cm2, for 12 sessions of 20 minutes each. Samples of tibia were subjected to histological analysis, blindly, with light microscopy and histomorphometric analysis by specific software Image-Pro 6.1. The average percentage of new bone formation were subjected to analysis of variance in subdivided parcels and multiple comparison test "Student-Newman-Keuls (SNK), with a significance level of 5%. The average values and standard deviations of the percentage of newly formed bone for the groups showed the least amount of bone repair G1t (13.62% ± 4.88%) - G1c (8.68% ± 4.16%) compared G2t groups (27.17% ± 11.36%) - G2c (10.10% ± 7.90%) and G3t (23.19% ± 5.61%) - G3c (15.74% ± 7 08%). However, the mean values and standard deviations of the percentage of newly formed bone repair in the tibia treated G2t and G3t were significantly higher when compared to the repair of tibia in the control group (G2c and G3c). Consequently, we conclude that ultrasound has helped to accelerate bone repair in both the presence and absence of cargo.

Aspectos radiográficos e densitométricos de fraturas experimentais do radio de cães tratadas com plasma rico em plaquetas

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

Laser terapêutico no reparo ósseo de ratos submetidos à ausência de carga

Low-intensity laser has been used as a physical agent in various fields of medical sciences such as bone and tissue repair. Meanwhile little is known about its effects in adverse conditions such as abolition of load and osteopenic. With the assumption that the laser Ga-Al-As accelerates the process of bone consolidation, goal of this study was to evaluate bone mineral density (BMD) in incomplete transverse osteotomies of tibia in adult rats, treated with low power laser therapy in three different groups: G1 (n = 10), reference 15 days; G2 (n=10), suspended by the tail and, accordingly, treated with laser for 12 days; G3 (n = 10), suspended by the tail by 36 days and that after 21 days, there was laser treatment for 12 days. The right tibia treated with laser and left served as control. The laser was used to Ga-Al-As, DMC - Flash Lase® III, with wavelength 830nm, 100 mW, 4J, 140 J / cm ², 40s of application in 12 sessions. It was used densitometer-Lunar DPX®, with computer program for "small animals", and the analysis of BMD was made in the bone throughout the region and the osteotomy. The results showed no efficacy of laser therapy in the process of bone repair, both in animals of group 1, as in group 2 and 3. It follows that either the low-power laser was not an effective performance or the effects of laser therapy is not only manifested at the site of irradiation as well as the systemic level.

Abordagens periodontais na promoção da harmonia do sorriso

Several therapeutic approaches have been proposed in order to achieve an esthetically pleasing and harmony smile. The present study reports a case in which gingivectomy was performed in the region of the upper anterior teeth combined with osteotomy in the region of the upper posterior teeth and removal of the superior labial frenum to promote harmony smile by decreasing the gummy smile and adequacy of buccal corridor. Osteoplasty gingivoplasty, and frenectomy procedures were planned and performed in a single session. The extraction of the maxillary third molars was also performed in order to avoid postoperative complications. Follow-up visits were performed at 7, 15, 30 and 180 days postoperatively. At 7 days, the gingival tissue was in the initial process of healing, demonstrating inflammation still in evidence. At 15 days, the gingival tissue was found in the final healing process, showing characteristics of normal health gum. At 30 days, there was complete healing of gingival tissues without clinical exposure of the root surfaces. After 180 days, tissues remained in healthy, demonstrating the success of the treatment. Patient showed complete satisfaction with the results. It can be concluded that, when properly indicated, the combination of gingivectomy, osteotomy and frenectomy procedures are promising therapeutic approaches for promoting harmony smile.

Osteotomia com brocas de alta e baixa rotação, com e sem refrigeração líquida: estudo histopatológico duplo cego em suínos

Nine swines of the White Large race were used for study of the process of bony repair after osteotomy with rotating instruments of low and high-speed, with and without liquid refrigeration. The authors observed, through double blind histopathological analysis, that in every analyzed operative time, the bony repair was processed more appropriately when the osteotomies were accomplished with liquid refrigeration. In the final postoperative times, of fourteen and twenty-eight days, the best results of bony repair were observed in the osteotomy accomplished with drills of low rotation and with liquid refrigeration, while in the postoperative time of seven days, the results of the bony repair of osteotomy accomplished with drills of high rotation and with liquid refrigeration they were better. The authors consider, still, that the process of bony repair in swine display larger proximity in the histological pictures among the studied variables, when compared with other biological models. As most of the works told in the literature it refers the use of dogs, the authors consider that the present work guarantees your importance in the sense of looking for a closer model of the man.