Evaluation of the effect of platelet-rich plasma on alveolar wound healing in rats / Evaluación del efecto del plasma rico en plaquetas en la cicatrización de heridas alveolares en ratas

Opinions about the clinical utility of platelet-rich plasma (PRP) vary, as a large number of experimental studies have questioned its efficacy. The purpose of this study was to evaluate the effects of PRP on experimental alveolar wound healing in rats. Fifty young adult male Wistar rats were divided in control and PRP groups and submitted to extraction of the right maxillary incisor. In the PRP group, blood was collected by cardiac puncture, and the socket was filled with a PRP gel. Animals were euthanized after 1, 3, 7, 14 and 30 days. Histological and histomorphometric analyses were performed at each experimental time point. Semiquantitative histological analysis showed that the PRP group exhibited significantly more collagen-matrix deposition and less bone-matrix formation in the socket than did the control group from 7 to 30 days. Histomorphometric analyses showed that the PRP group also exhibited lower bone-tissue areas than the control group at 7 (p=0.0250) and 14 days (p<0.0001), but at 30 days, no significant difference between the groups was observed. In the present study, PRP did not enhance alveolar wound healing, and PRP-treated rats exhibited low rates of bone deposition during the intermediate phases of alveolar socket repair.

Las opiniones sobre la utilidad clínica del plasma rico en plaquetas (PRP) varían, ya que un gran número de estudios experimentales han cuestionado su eficacia. El propósito de este estudio fue evaluar los efectos del PRP sobre la cicatrización experimental de heridas alveolares en ratas. Cincuenta ratas Wistar adultas fueron divididas en grupos control y PRP, y fueron sometidas a extracción del incisivo maxilar derecho. En el grupo de PRP, la sangre se recogió por punción cardiaca, y el alvéolo se llenó con un gel de PRP. Los animales se sacrificaron después de 1, 3, 7, 14 y 30 días. Se realizaron análisis histológicos e histomorfométricos en cada momento experimental. El análisis histológico semicuantitativo mostró que el grupo de PRP exhibió significativamente más deposición de matriz de colágeno y menos formación de matriz ósea en el receptáculo que el grupo control de 7 a 30 días. Los análisis histomorfométricos mostraron que el grupo PRP también exhibió áreas de tejido óseo inferiores al grupo control a 7 (p = 0,0250) y 14 días (p <0,0001), pero a los 30 días no se observó diferencia significativa entre los grupos. En el presente estudio, el PRP no mejoró la cicatrización de las heridas alveolares, y las ratas tratadas con PRP mostraron bajas tasas de deposición ósea durante las fases intermedias de la reparación de los receptáculos alveolares.

Trends in Le Fort Fractures at a South American Trauma Care Center: Characteristics and Management.

PURPOSE: To assess the trends in Le Fort (maxillary) fractures in patients seen at a South American trauma care center based on the characteristics and management of these. MATERIALS AND METHODS: Of all patients with facial fractures seen at a trauma hospital during a six-year period, 50 (6.6 %) presented with Le Fort fractures. Medical charts were reviewed for characteristics presented and management performed. To improve the analyses, computed tomography and intraoperative findings were used. Statistical analyses involved descriptive statistics and the likelihood ratio test. RESULTS: The fractures were Le Fort II (52 %), Le Fort I (22 %), Le Fort type-associated (20 %) and Le Fort III (6 %). Male patients (90 %) in their third decade of life (38 %) were more frequent (p = 0.022). Traffic accidents (56 %) were the major etiologic factor (p = 0.048). There were 1.4 additional facial fractures per patient, with predominance of zygoma fractures (36.5 %). Most of the cases were managed by open reduction (60 %) (p = 0.015) with the subciliary approach (42.7 %) (p = 0.001). The 1.5-mm system was the most used fixation and the zygomaticomaxillary suture the most frequent location (p = 0.001). CONCLUSION: the most common patient with a Le Fort fracture is an adult male, with a Le Fort II fracture due to a traffic accident requiring surgical fixation on zygomaticomaxillary suture.

Characteristics and management of patients requiring hospitalization for treatment of odontogenic infections.

Odontogenic infections usually respond well to outpatient care; however, these can be very complicated and demand hospitalization. The aim of this study was to assess retrospectively the characteristics and medical management of patients needing hospitalization for the treatment of odontogenic infections. The personal data, symptoms presented, and therapeutic procedures adopted were analyzed. The predominant age group was from 0 to 10 years (30%), and a sex relation of 1:1 was found, but there was no significant difference (P = 0.337). The most frequent diagnosis was of dentoalveolar abscess (86.3%). Pain (47.1%) was the prevailing reason for hospitalization, with pulpal necrosis (67.5%) as the main cause. There was a prevalence of involvement of the lower permanent teeth (41.4%) and lower deciduous teeth (23%). The prevalent clinical aspect was submandibular or facial swelling (61.4%). The most administered antibiotic was penicillin G associated with metronidazole (25.3%). Most cases (58.7%) presented regression with antibiotic therapy, and in some cases, surgical drainage was necessary (18.7%). One case of Ludwig angina resulted in death. The mean length of hospital stay was 4.4 days, being higher in the cases of Ludwig angina. It was concluded that most cases of odontogenic infections requiring hospitalization were of dentoalveolar abscess occurring in young people of both sexes, associated to the lower permanent molar teeth, presenting with swelling, with regression of the symptoms after antibiotic therapy and hospitalization for some days, with some of the cases requiring drainage.

Factors contributing to the surgical retreatment of mandibular fractures

The purpose of this retrospective study was to evaluate contributing factors in patients requiring surgical retreatment of mandibular fractures. Of all the patients with mandibular fractures who were treated using internal fixation at a trauma hospital over a seven-year period, 20 patients (4.7%) required a second surgery and thus composed the “reoperated” group. The control group comprised 42 consecutive patients with mandibular fractures who were treated at the same clinic and who healed without complications. Medical charts were reviewed for gender, age, substance abuse history, dental condition, etiology, location of fracture, degree of fragmentation, fracture exposure, teeth in the fracture line, associated facial fractures, polytrauma, time elapsed between trauma and initial treatment, surgical approach and fixation system. Statistical analyses were performed using the Statistical Package for Social Sciences (SPSS) version 20.0; descriptive statistics and the chi-squared test were used to determine differences between groups. Significant differences in substance abuse (p = 0.006), dental condition (p < 0.001), location of fracture (p = 0.010), degree of fragmentation (p = 0.003) and fracture exposure (p < 0.001) were found. With regard to age and time elapsed between trauma and initial treatment, older patients (31.4 years, SD = 11.1) and a delay in fracture repair (19.1 days, SD = 18.7) were more likely to be associated with reoperation. It was concluded that substance abuse, age, dental condition, location of fracture, degree of fragmentation, fracture exposure and the time between trauma and initial treatment should be considered contributing factors to the occurrence of complications that require surgical retreatment of mandibular fractures.

Factors contributing to the surgical retreatment of mandibular fractures.

The purpose of this retrospective study was to evaluate contributing factors in patients requiring surgical retreatment of mandibular fractures. Of all the patients with mandibular fractures who were treated using internal fixation at a trauma hospital over a seven-year period, 20 patients (4.7%) required a second surgery and thus composed the "reoperated" group. The control group comprised 42 consecutive patients with mandibular fractures who were treated at the same clinic and who healed without complications. Medical charts were reviewed for gender, age, substance abuse history, dental condition, etiology, location of fracture, degree of fragmentation, fracture exposure, teeth in the fracture line, associated facial fractures, polytrauma, time elapsed between trauma and initial treatment, surgical approach and fixation system. Statistical analyses were performed using the Statistical Package for Social Sciences (SPSS) version 20.0; descriptive statistics and the chi-squared test were used to determine differences between groups. Significant differences in substance abuse (p = 0.006), dental condition (p < 0.001), location of fracture (p = 0.010), degree of fragmentation (p = 0.003) and fracture exposure (p < 0.001) were found. With regard to age and time elapsed between trauma and initial treatment, older patients (31.4 years, SD = 11.1) and a delay in fracture repair (19.1 days, SD = 18.7) were more likely to be associated with reoperation. It was concluded that substance abuse, age, dental condition, location of fracture, degree of fragmentation, fracture exposure and the time between trauma and initial treatment should be considered contributing factors to the occurrence of complications that require surgical retreatment of mandibular fractures.

Evaluation of surgical retreatment of mandibular fractures.

INTRODUCTION: Mandibular fractures are frequent, and treatment for these fractures involves rigid fixation. Complications can occur after treatment and may require a new surgical procedure; however, there are limited studies evaluating surgical retreatment. AIM: The purpose of this retrospective study was to evaluate the characteristics and the types of treatment carried out in patients requiring surgical retreatment of mandibular fractures. MATERIALS AND METHODS: From all patients with mandibular fractures treated by rigid internal fixation at a trauma hospital during a 7-year-period, 20 patients (4.7% of the cases) required a second surgery. RESULTS: The most common complaints were pain, infection with the presence of fistula, and abnormal mobility. There was a predominance of Staphylococcus aureus in the bacterial culture. The most frequent radiographic images were diffuse bone resorption, loosening of screws, and a visible fracture line. The diagnoses were nonunion in 10 (50%) cases, soft tissue infection associated with screw loosening or plate exposure in 7 (35%) cases, osteomyelitis in 2 (10%) cases, and malunion in 1 (5%) case. Seven cases of nonunion presented with fistula, and four of these patients had bone sequestration. The required procedures included new fixation in 6 (30%) patients, removal of bone sequestration and new fixation in 4 (20%) patients, surgical exploration and removal of fixation material in 7 (35%) patients, removal of bone sequestration in 2 (10%) patients, and refracture in 1 (5%) patient. CONCLUSION: It was concluded that most cases requiring surgical retreatment of mandibular fractures comprised nonunion or soft tissue infection associated with screw loosening or plate exposure. Consequently, the main procedures needed were new fixation or surgical exploration with the removal of fixation material.

Chromosome evolution in three Brazilian Leptodactylus species (Anura, Leptodactylidae), with phylogenetic considerations.

Karyotypic analyses on three species of the Leptodactylus from Brazil showed 2n=24 in L. cf. marmoratus, 2n=23 in Leptodactylus sp. (aff. bokermanni), and 2n=26 in L. hylaedactylus, with distinct numbers of bi and uni-armed chromosomes. Leptodactylus cf. marmoratus presented a variation as regard to the morphology of pair 12. All specimens of L. cf. marmoratus had Ag-NOR in pair 6, confirmed by FISH, but the sample from one of the localities presented additional Ag-NOR, in one of the chromosomes 8. In Leptodactylus sp. (aff. bokermanni) and L. hylaedactylus the chromosome pairs bearing Ag-NOR are 11 and 7, respectively. The C banding patterns are predominantly centromeric, but only in L. marmoratus this heterochromatin appeared very brilliant with DAPI. On the other hand, bright labelling was noticed with CMA(3) in the three species, on the Ag-NOR site. The data obtained here are in accordance with the proposed phylogeny to the genus, and the chromosomal analyses in these Leptodactylus showed that the karyotype evolution was based mainly in centric fusion and pericentric inversion.

Effects of unilateral upper incisor extraction on facial growth of young rats / Efeitos da extração unilateral de incisivo superior no crescimento facial de ratos jovens

The effects of unilateral extraction of the upper incisor (one tooth) on facial growth of young rats were studied. The remaining upper incisor showed deviation towards the opposite side, and there was regular dental wear of all the incisors. The effects were evident only in the mid-facial area. Cephalometric measurements showed significant shortening with deviation of the incisor bone on the extraction side. There was no significant disturbance of the growth of the rest of the maxilla and mandible. These results indicate that upper incisor extractions have a localized influence, leading to impairment of incisor bone growth

Passive mandibular border positions and their relationships with signs and symptoms of craniomandibular disorder / Movimentos mandibulares máximos e suas relações com sinais e sintomas da disfunção craniomandibular

Linear measurements of passive mandibular border positions and angular measurements of passive opening were recorded in a group of patients with craniomandibular disorders. The relationship between signs and symptoms of craniomandibular disorders and abnormal capacity of movement were studied. There was significant association of some signs and symptoms related to the temporomandibular joint and abnormal vertical and horizontal excursions. On the other hand, there was only one relationship between occlusal factors and abnormal passive mandibular border positions

Resposta tecidual óssea frente à hidroxiapatita granular implantada em efeitos criados na mandíbula de ratos / Bone tissue response to granular hydroxyapatite implanted in experimental defects in the rat mandible

Foi realizada avaliaçäo histológica da resposta tecidual óssea frente à hidroxiapatita (HA) granular implantada em defeitos criados experimentalmente na mandíbula de ratos. Inicialmente, foi observada a presença de exsudato sero-fibrinoso, com grande quantidade de polimorfonucleares neutrófilos e, a seguir, ocorreu processo inflamatório crônico. Posteriormente, foram observadas células gigantes multinucleadas ao redor da imagem negativa dos cristais. Esse achado permaneceu até os períodos finais do experimento, configurando reaçäo do tipo corpo estranho, havendo também, nessa fase, atividade osteogênica ao redor do defeito ósseo

Estudo comparativo das excursöes mandibulares máximas, obtidas com e sem pressäo bidigital, em pacientes com disfunçäo dolorosa da articulaçäo temporomandibular / A comparative study of mandibular border positions, under and without forcible expansion, in temporomandibular joint pain dysfunction patients

Foi realizado estudo comparativo das excursöes mandibulares máximas, obtidas com e sem pressäo bidigital, em pacientes portadores de disfunçäo dolorosa da articulaçäo temporomandibular. Foram avaliadas a abertura máxima, a lateralidade direita e a esquerda e a protrusäo máxima. Para cada movimento, foram obtidas 3 mensuraçöes consecutivas. Näo foi verificada estatisticamente significante entre os valores obtidos com e sem pressäo bidigital para a maioria das excursöes mandibulares. Apenas para a lateralidade esquerda a diferença foi significante (p<0,02), sendo aventadas hipóteses para este fato. Näo foi observada diferença significante entre as 3 mensuraçöes

Transfixaçäo de fio de Kirschner no tratamento de fraturas instáveis do complexo zigomático / Kirschner wire transfixation in the treatment of unstable fractures of the zygomatic complex

Neste trabalho, analisamos a utilizaçäo da transfixaçäo de fio de Kirschner no tratamento de fraturas instáveis do complexo zigomático. Foram avaliados, clínica e radiograficamente, 15 pacientes portadores de fraturas instáveis do complexo zigomático. O fator etiológico mais frequente foi o acidente automobilístico, sendo o sinal principal o edema. Houve maior freqüência de fraturas com deslocamento e rotaçäo no sentido medial. Foi realizada reduçäo através de via percutânea ou temporal, seguida de transfixaçäo com fio Kirschner ancorado no palato duro. A maioria dos casos tratados através desse método apresentou bom resultado. Näo foram observadas complicaçöes que podem ocorrer diante de métodos cruentos de tratamento. Podemos concluir que a transfixaçäo com fio de Kirschner é um método eficiente para contençäo de fraturas instáveis do complexo zigomático

Avaliação das excursões mandibulares máximas em indivíduos assintomáticos / Evaluation of maximal mandibular movements in asymptomatic individuals

Foram avaliadas as excursões mandibulares máximas em indivíduos assintomáticos, representados por estudantes de Odontologia. As medidas foram realizadas sob leve pressão bidigital para os movimentos de abertura máxima e lateralidades direita e esquerda. Os movimentos de abertura e protrusão tiveram os seus valores corrigidos pela adição das medidas dos trepasses vertical e horizontal, respectivamente. Cada movimento foi mensurado três vezes, em cada indivíduo. Para a comparação dos valores obtidos entre os sexos masculino e feminino foi aplicado o teste "t" de Student, sendo verificada diferença apenas para a abertura máxima. As três mensurações foram comparadas duas e duas e, através do teste "t" de Student, não foi observada diferença. É sugerida a necessidade de apenas uma medição para cada movimento

Ferimento na região temporomandibular: uma causa de limitação da abertura de boca / Wounding of the temporomandibular region: a cause of jaw opening limitation

É relatado um caso de limitação da abertura da boca por ferimento com arma branca na região temporomandibular. O paciente apresentou-se com queixa de dor e limitação funcional após agressão com faca na face. A conduta conservadora, com o uso de antinflamatório, permitiu boa evolução, sendo recuperada a abertura normal de boca. A possibilidade do processo inflamatório ter estimulado o espasmo muscular é destacada