Processo de reparo alveolar frente à administração de bifosfonato nitrogenado: avaliação comparativa em camundongos 129/Sv-WT e 129/Sv 5-LOKO / Alveolar bone repair of mice under administration of bisphosphonate containing nitrogen: comparative investigation between 129/Sv-WT and 129/Sv 5- LOKO

A instalação das osteonecroses dos maxilares(OM) tem sido relacionada ao uso crônico de medicamentos antirreabsortivos indicados para doenças e distúrbios do metabolismo ósseo, como os bifosfonatos nitrogenados (nBF), especialmente quando associados a intervenções cirúrgicas-odontológicas. Deste modo, especulase que a instalação desta doença não ocorre somente devido à condição do tecido ósseo e sua capacidade reacional, mas principalmente pela sua condição de defesa imunológica. O presente estudo tem como objetivo analisar o padrão de reparo ósseo de alvéolos dentários de incisivos superiores recém-extraídos de camundongos 129/Sv geneticamente modificados (knockouts ­ KO) para a enzima 5-lipoxigenase (5-LO), os quais apresentam fenótipo esqueletal osteopetrótico, comparando-os com tipo selvagem (Wild Type ­ WT), com e sem administração de nBF. Para tanto foram utilizados 80 camundongos machos com idades variando entre 8 e 10 semanas, sendo 46 animais 129/Sv WT e 46 animais 129/Sv 5-LOKO, os quais foram submetidos à exodontia do dente incisivo superior direito e divididos em quatro grupos de acordo com o tratamento: Grupo WT ­ 0,1 ml de soro fisiológico 0,9%, Grupo WT-ZL ­ 0,5 mg/Kg de ácido zoledrônico (ZL), Grupo 5- LOKO - 0,1 ml de soro fisiológico 0,9%, Grupo 5-LOKO-ZL ­ 0,5 mg/Kg de ZL, sendo ambas soluções administradas intraperitonealmente (IP) 1x por semana até o final do experimento. Após os períodos de 7, 14 e 30 dias, cinco animais de cada grupo foram submetidos à eutanásia para remoção das maxilas direitas contendo os alvéolos para as análises histopatológica, histomorfométrica e imuno-histoquímica para COX-2, OPG, RANKL e TRAP. Os resultados não mostraram diferença significativa para a quantidade de matriz óssea entre os grupos WT, KO e WT-ZL. Contudo, foi observado que o grupo KO-ZL apresentou significativamente menos matriz óssea em todos os períodos quando comparado com WT-ZL, além de maior quantidade de células inflamatórias no 14 e 30 dias. Observou-se aumento significativo de células COX-2+ no grupo WT aos 14 dias em comparação com os demais. Detectou-se aumento de OPG ao final do reparo em todos os grupos. Aumento significativo de RANKL foi observado no grupo KO aos 7 dias, em comparação com 5-LOKO, sendo que ao final do reparo WT-ZL mostrou células RANKL+ significativamente elevadas em comparação com WT e KO-ZL. No entanto, somente aos 14 dias observou-se aumento significativo de células TRAP+ nos grupos WT e WT-ZL em comparação com KO e KO-ZL. A partir destes resultados, pode-se concluir que os animais 5-LOKO apresentaram formação óssea precoce em alvéolos dentários pós-exodontia comparados com os animais WT. No entanto, os efeitos do ZL foram mais deletérios nos camundongos 5-LOKO, possivelmente pela influência da droga e efeitos da inibição desta enzima nos eventos inflamatórios no curso do reparo(AU)

Osteonecrosis of the jaws has been related to the chronic use of antiresorptive drugs indicated for diseases and disorders of bone metabolism, such as nitrogenous bisphosphonates (nBP), especially when associated with surgical-dental interventions. Thus, it is speculated that the onset of this disease does not occur only due to the condition of the bone tissue and its reactive capacity, but mainly due to its immunological defense condition. The present study aimed to analyze the bone repair pattern of dental alveoli of maxillary incisors recently extracted from 129/Sv 5- LOKO mice, which had an osteopetrotic skeletal phenotype, comparing them with wild type, 129/Sv WT, with and without administration of nBP. For that, 80 male mice were used with ages varying between 8 and 10 weeks, being 46 animals 129/Sv WT and 40 animals 129/Sv 5-LOKO, which were submitted to the extraction of the upper right incisor tooth and divided into four groups of according to treatment: WT Group - 0.1 ml of 0.9% saline solution, WT-ZL Group - 0.5 mg/Kg of zoledronic acid, Group 5- LOko - 0.1 ml of 0.9 saline solution %, Group 5-LOko-ZL ­ 0.5 mg/Kg of zoledronic acid, both solutions being administered intraperitoneally (IP) 1x a week until the end of the experiment. After periods of 7, 14 and 30 days, five animals from each group were euthanized to remove the right jaws containing the alveoli. They were immediately fixed in order to be prepared for the following methodological procedures: histotechnical processing for making histological slides stained with hematoxylin and eosin and immunohistochemical No significant difference was found for the amount of bone matrix between the WT, KO and WT-ZL groups. However, it was observed that the KO-ZL group presented significantly less bone matrix in all periods when compared to WT-ZL, in addition to a greater amount of inflammatory cells at 14 and 30 days. There was a significant increase in COX-2+ cells in the WT group at 14 days compared to the others. An increase in OPG was detected at the end of the repair in all groups. Significant increase in RANKL was observed in the KO group at 7 days, compared to 5-LOKO, and at the end of repair WT-ZL showed significantly elevated RANKL+ cells compared to WT and KO-ZL. However, only at 14 days there was a significant increase in TRAP+ cells in the WT and WT-ZL groups compared to KO and KO-ZL. From these results, it can be concluded that 5-LOKO animals showed early bone formation in post-extraction tooth sockets compared to WT animals. However, the effects of ZL were more deleterious in 5-LOKO mice, possibly due to the influence of the drug and the effects of inhibition of this enzyme on inflammatory events in the course of repair(AU)

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.

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.

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.