Lack of 5-lipoxygenase in intramembranous and endochondral 129Sv mice skeleton and intramembranous healing.

OBJECTIVE: To analyze the lack of 5-lipoxygenase (5LO) on dental socket healing and post-natal phenotype of intramembranous and endochondral bones. DESIGN: Wild type (WT) 129/SvEv (n = 20) and 5LO knockout (5LOKO) (n = 20) male mice underwent tooth extraction of the upper right incisor and were euthanized after 7, 14, and 30 day time points for the evaluation of dental socket healing and histological phenotyping of intramembranous (IM) and endochondral (EC) bones. Microscopic analysis of alveolar sockets included histopathological description, histomorphometry, and immunohistochemistry for 5LO, cyclooxygenase 2 (COX2), and tartrate resistant acid phosphatase (TRAP). RESULTS: Histological phenotyping revealed thicker cortical bone in EC bones (femur and vertebra) of 5LOKO mice compared to WTs, with no differences in collagenous content. Although dental socket healing was similarly observed in both groups, WT mice revealed increased numbers of COX-2+ and 5LO+ cells during bone maturing stage, with a decrease of TRAP+ cells at day 30. On the other hand, an increased quantity of fibroblasts was observed at day 7 in 5LOKO group, as well as increased inflammatory infiltrate and significantly decreased TRAP+ cells at final stages of alveolar socket healing in comparison to WTs. CONCLUSIONS: The lack of 5LO in 5LOKO mice resulted in thicker cortical of EC, but not of IM post natal bones. Furthermore, genetic deletion of 5LO in the 5LOKO mice directly affected the inflammatory response during socket healing, influencing initial and late phases of bone repair in a model of post-tooth extraction in 129Sv WT and 5LOKO mice.

Medication-related osteonecrosis of the jaws after tooth extraction in senescent female mice treated with zoledronic acid: Microtomographic, histological and immunohistochemical characterization.

Treatment with cumulative dosages of zoledronic acid (ZA) in elderly patients is a risk factor for the development of medication-related osteonecrosis of the jaws (MRONJ), mainly related to surgical triggers such as tooth extraction. However, animal models for the investigation and understanding of MRONJ pathophysiology in senescent and postmenopausal stages remains to be developed and characterized. The aim of this study was to analyze MRONJ development in senescent female mice treated with cumulative dosages of ZA. For this purpose, twenty 129/Sv female mice, 64 weeks old, were treated with 0.9% saline solution as control group (n = 10), and with ZA at 250µg/Kg (n = 10), once a week, starting 4 weeks before the upper right incisor extraction and until the end of the experimental time points (7 days and 21 days). At 7 and 21 days post-surgery, specimens were harvested for microCT, histological, birefringence and immunohistochemical analysis. Clinically, an incomplete epithelialization was observed in ZA group at 7 days and a delayed bone matrix mineralization and collagen maturation at 7 and 21 days compared to the controls. Controls revealed sockets filled with mature bone at 21 days as observed by microCT and birefringence, while ZA group presented delayed bone deposition at 7 and 21 days, as well increased leukocyte infiltration and blood clot at 7 days, and increased bone sequestrum and empty osteocyte lacunae at 21 days (p<0.05). Also, ZA group presented decreased quantity of TGFb+ and Runx-2+ cells at 7 days, and decreased quantity of TRAP+ osteoclasts compared to the control at 21 days (p<0.05). Altogether, these data demonstrate the usefulness of this model to understanding the pathophysiology of MRONJ.

Oral Myiasis in a Patient With HIV Manifestations and Neurologic Toxoplasmosis Treated by Ivermectin.

Myiasis has been defined as a pathologic condition where dipterous larvae are lodged in mammalian hosts causing an infestation, which feeds on living or dead tissue for at least a certain period inside the host and develops itself as parasites. In humans, the most commonly affected sites are the nose, eyes, skin wounds, sinuses, lungs, ears, gut, gall bladder, vagina, nasal cavities, and rarely the mouth because the oral tissues are rarely exposed to the external environment. The etiology of oral myiasis is usually related to local factors such as poor oral hygiene, periodontal disease and labial incompetence, and systemic factors such as neurologic deficits.

Simplified Access for Reduction and Fixation of a Frontal Bone Fracture.

The frontal bone fractures occur very often in service units in oral and maxillofacial surgery. Bicoronal access is the most common for the surgical treatment of frontal bone fractures. However, patients are surprised when they receive notice that such invasive access will be made. This approach allows adequate visualization of the fracture site, but may be associated with complications, which can be avoided by the use of less invasive techniques. We describe an alternative approach that aims to minimize the complications of a coronal incision.

Respiratory Obstruction Due to Richards Type 4 Fracture.

Facial fractures can be potentially fatal in polytraumatized patients due to retropositioning tissues to upper airway obstruction. In the first aids, this situation can be reversed using a tracheostomy procedure to break out the airways. However, fractures leading to airway obstruction are rare and according to Richards Classification can be classified into 5 types. The purpose of this article is to report a clinical patient with a bilateral condylar and mandibular symphysis fractures that resulted in airway obstruction and severe mandibular rear projection.

Avaliação do papel da fibrina rica em plaquetas em defeito crítico cirurgicamente criado em calota de ratos induzidos à hipercolesterolemia tratados ou não com atorvastatina / Evaluation of the role of Platelet Rich Fibrin in surgical critical-size calvarial defect in rats with diet-induced hypercholesterolemia treated or not with atorvastatin

Objetivos: avaliar a ação da membrana de fibrina rica em plaquetas, na reparação óssea, em defeito crítico de calota de ratos induzidos à hipercolesterolemia, bem como a atuação do tratamento de atorvastatina nesse processo Materiais e método: 40 defeitos críticos de 6 mm de diâmetro foram criados em calotas cranianas de ratos. Cada defeito foi aleatoriamente dividido em 8 grupos experimentais (GC, GCPRF, GCA, GCH, GHA, GPRFA, GPRFH, GPRFHA), avaliados aos 28 dias pós-operatórios com análises histológica e microtomográfica. Resultados: Os resultados mostraram que houve formação óssea em todos os grupos analisados. O grupo GPRFH apresentou formação óssea mais acentuada com relação aos demais grupos. Dos grupos em que foi administrado atorvastatina, o GPRFHA apresentou maior taxa de formação óssea (p<0,05). Conclusão: Com a metodologia utilizada, a fibrina rica em plaquetas, quando associada à condição de hipercolesterolemia, induziu ao aumento da formação óssea(AU)

Objectives: The aim of this study was to evaluate the efficacy of Platelet Rich Fibrin (PRF) in the healing process of surgically created critical-size defects in rat calvarial induced to hypercholesterolemia treated or not with atorvastatin. Materials and method: 40 critical defects were created with 6 mm diameter calvaria of rats. Each defect was randomly divided into eight experimental groups (GC, GCPRF, GCA, GCH, GHA, GPRFA, GPRFH, GPRFHA), evaluated at 28 postoperative days for histomorphometry and microtomography. Results: The results showed new bone formation in all groups. The GPRFH group just did differ from all groups in the new bone formation (p<0.05). Among the groups treated with atorvastatin, the GPRFHA group showed the highest bone formation rate. Conclusion: With the methodology used, the platelet-rich fibrin associated with the hypercholesterolemia induced to new bone formation(AU)

Andy Gump Fracture of the Mandible in a Pediatric Patient.

The mandibular fractures in pediatric patients are rare, and they can need a fast and safe treatment. We present a case of a pediatric patient with "Andy Gump" fracture, resulting in a retrognathic mandible, distress to breathe, and functional discomfort to the patient caused by a cycling accident. The treatment was successful with the fast release of airway path and use of titanium plates to fix the fracture.