Evaluation of ortogonblender software bone movement tools in bimaxillary orthognatic surgeries performed in dolphin software.

The aim of this observational, longitudinal and retrospective study was to evaluate the fidelity of virtual surgical planning (VSP) performed on Dolphin Imaging & Management Solutions® 11.95 software on hard tissues, using the tools of the open-source software OrtogOnBlender - Blender3D. For this, linear, angular and 7-point anatomical measurements of the skeletal profile were used, and the discrepancies between the VSP and the result after bimaxillary orthognathic surgery were calculated. Pre- and postoperative cone beam CT (CBCT) scans of 43 consecutive patients with class II and III skeletal deformities were evaluated and the results of the VSP were compared to the 1-month postoperative results. All overlapping points presented values within the range considered clinically irrelevant (< 2 mm and < 4°) and differences were not significant (p > 0.05). The comparison of anatomical points showed lower values (≤ 2.11 mm) in point A of class II. For hard tissues, the comparison between VSP and 1-month postoperative tomography demonstrated the faithful results of virtual planning using this software.

Strategies and operational procedures in oral radiology to mitigate potential SARS-CoV-2 transmission / Estrategias y procedimientos operacionales en Radiología Oral para mitigar transmisión de SARS-CoV-2

SUMMARY Coronavirus disease (COVID-19) is highly transmissible through respiratory droplets, saliva, and aerosol particles. Infection can lead to severe acute respiratory syndrome and trigger multi-organ failure and death. Most clinical dental procedures involve contact with saliva or the generation of aerosols with saliva and blood. These airborne particles increase the risk of transmission by COVID-19 between dentists and patients. Thus, dentistry must adopt procedures to reduce transmission during dental procedures. Although these strategies may not be directly applicable to all institutions due to cultural, social, geographical, and economic differences, the underlying principles and implemented strategies remain relevant and can be adopted or modified by the institutions dealing with the current COVID-19 outbreak. The purpose of this article is to discuss one of the principal sources of COVID-19 transmission: saliva, the biofluid most frequently handled in a radiology environment. The authors also recommend strategies and operational procedures to decrease the spread of COVID-19 in a radiological routine.

RESUMEN La enfermedad por coronavirus (COVID-19) se transmite fácilmente a través de gotitas respiratorias, saliva y partículas de aerosol. La infección puede desencadenar un síndrome respiratorio agudo severo, insuficiencia multiorgánica y, en algunos casos, la muerte. Los procedimientos clínicos dentales determinan el contacto con saliva o la generación de aerosoles con saliva y sangre, lo que implica un alto riesgo de transmisión por COVID-19 entre odontólogos y pacientes. Por ello, la práctica odontologica debe adoptar medidas para detener la propagación durante los procedimientos dentales. En este artículo se revisan las estrategias para mitigar el riesgo de transmisión de COVID-19. Si bien estas estrategias pueden no ser directamente aplicables a todas las instituciones debido a diferencias culturales, sociales, geográficas y económicas inherentes, los principios subyacentes y las estrategias implementadas siguen siendo relevantes y pueden ser adoptados o modificados por las instituciones que se ocupan del brote actual de COVID-19. El propósito de este artículo es discutir una de las principales fuentes de transmisión de COVID-19: la saliva, el biofluido que se maneja con mayor frecuencia en un entorno radiológico. Los autores también recomiendan estrategias y procedimientos operativos para disminuir la propagación de COVID-19 en una rutina radiológica.

Effect of alendronate on healing of bone defect and gingival tissue in osteopenic rats / Efecto del alendronato en la reparación de defectos óseos y tejido gingival en ratas con osteopenia

The aim was to evaluate bone repair and gingival tissue repair in osteopenic rats. Fifteen female wistar rats were included; in all of them ovariectomy was realized to induce osteopenia; after 45 days, the animals were submitted to 2 surgical techinques 1) dental extraction of the upper central incisor with no socket preservation and 2) 5 mm cranial defect in the calvarium; 5 rats were included in the control group (G1) withput alendronate application; in the group 2 (G2) was used subcutenous alendronate (0.5 mg/kg) once for three weeks and then was realizd the both surgical techniques. In group 3 (G3), after ovariectomy was realized the both dental extraction and the calvarium defect and after that was realized the alendronate protocol. In each group, after six week was realized euthanasia and descriptive histological analysis of the surgical areas involved. In bone formation of the 5 mm cranial defect was observed with good progression in the 3 experimental models and no modification in quality of bone repair was observed. For the gingival tissue in the extraction socket, no differences were observed between G1 and G3. On other hand, in G2 a thinner and reduced gingival epithelium was found. Our results showed that alendronate was not an obstacle for bone repair; deficiencies in re-epithelialization of oral mucosa show the impact of alendronate before dental extraction.

El objetivo fue evaluar la reparación ósea y gingival en ratas con osteopenia. Quince ratas wistar hembras fueron incluidas; en todas ellas se realizo ovarectomia y fue realizada la inducción de osteopenia; después de 45 días, los animales fueron sometidos a dos técnicas quirúrgicas 1) extracciones dentales del incisivo central superior sin preservación alveolar y 2) creación de un defecto craneano de 5 mm en la calota; 5 animales fueron incluidos como grupo control (G1) sin la aplicación de alendronato; en el grupo 2 (G2) se utilizó alendronato subcutáneo (0,5 mg/kg) una vez a la semana durante 3 semanas. En el grupo 3 (G3), después de la ovarectomia se realizó la exodoncia y el defecto en el cráneo y después de ello se inicio el protocolo con alendronato. En cada grupo, después de seis semanas se realizó la eutanasia con descripción histológica de los hallazgos. En el hueso formado en el defecto craneano de 5 mm se observó una adecuada progresión de reparación en los 3 modelos experimentales y no se observó cambios importantes en el modelo de reparación. Para el tejido gingival en el sitio de extracción, no se observaron diferencias entre el grupo G1 y G3. Por otra parte, el G2 presentó un tejido mas delgado con reducción del epitelio gingival; nuestros resultados demuestran que el alendronato no fue un obstáculo en la reparación ósea; deficiencias en la re epitelización de la mucosa oral muestran el impacto del alendronato después de la exodoncia.

COVID-19 y la odontología: una revisión de las recomendaciones y perspectivas para Latinoamérica / COVID-19 and dentistry: a review of recommendations and perspectives for Latin America

COVID-19 es una enfermedad altamente contagiosa y potencialmente mortal que nos acompañara por largo tiempo. Las profesiones de la salud y la vida en general ha sido afectada de forma significativa en todo lugar del mundo. La odontología ha pasado de una etapa de gran desarrollo clínico a una etapa donde el manejo de barrera de protección, el control de tratamientos y el tiempo asignado a los pacientes cambiará la forma de realizar la profesión. El presente trabajo pretende resumir las indicaciones y recomendaciones basadas en la evidencia disponible y realizar un análisis de la condiciones de salud oral para Latinoamérica en esta época de pandemia.

COVID-19 is a profound, highly contagious and life-threatening viral disease that will be with us for a long time. Health Care-related professions and life in its entirety are significantly, and perhaps irreversibly affected, all around the World. COVID-19 is and will continue to transform Dentistry and its practise. Based on the available evidence accrued to date, this work attempts to address such changes, current and anticipated, as well as present recommendations for clinical practise implementation, tailored for Latin/South America, in light of such lifealtering momentous pandemic.

Prevalence of facial trauma in contact sports practitioners in the Federal District of Brazil

Abstract Aims: The purpose of this study is to assess the prevalence of oral and dentoalveolar trauma among contact sports practitioners in the Federal District of Brazil. Methods: A cross-sectional descriptive study was conducted using a questionnaire developed specifically for this research regarding the occurrence of facial trauma, site of injuries, how they occurred, the approach is taken to solve the problem, and the use of several types of mouthguards. Data were analyzed using the SPSS 20.0 software, and the chi-square test (X2) was chosen to examine the differences between categorical variables. The results were considered statistically significant for p<0.05. Results: A total of 141 athletes were interviewed, with a prevalence of facial trauma of 65.2%, which was higher in professional athletes (71.1%). Lesions ranged from soft tissue lacerations to combined trauma; and the most frequent injuries were soft tissue laceration (53.3%), combined trauma (16.3%), and dental fracture (9.8%). Only 20.6% of the participants required treatment for related injuries. Regarding the use of mouthguards, 34% of the athletes reported regular use of this device, and Type II mouthguard was the most used (39.7%). Dentists participate in the process of production and dissemination of mouthguards in 17.1% and 10.5% of cases, respectively. Conclusion: The data showed that most athletes are not aware of the importance of using mouthguards. The dentist must be more present in the area of sports dentistry, both for awareness and production of these devices, which support the safe practice of contact sports.

Cutaneous Fistula Associated with Salivary Calculi in the Parotid Gland: Report of a Rare Case / Fístula cutánea asociada a cálculos salivales en la glándula parótida: reporte de un caso raro / Fístula Cutânea Associada a Cálculos Salivares na Glândula Parótida: Relato de Caso Raro

Abstract The formation of calcific concretions in the salivary duct or glands is a common disorder, but parotid calculi represent only a small proportion of all salivary calculi. This case describes a rare coexistence of a cutaneous fistula with salivary stones located in the superficial lobe of the parotid gland that was removed under local anesthesia. This patient provides illustration of the difficulty there may be in establishing the diagnosis of parotid calculus. We believe that the report of this rare case will help health professionals, reinforcing the importance of proper diagnosis based on clinical and imaging evaluations.

Resumen La formación de concreciones calcificadas en el conducto salival o glándulas es un trastorno común, pero los cálculos de la parótida representan una pequeña parte de los cálculos salivares. Nosotros describimos este raro caso de la presencia de una fístula de piel asociada a un cálculo salivar del lóbulo superficial de la glándula parótida que foi removido sobre anestesia local. Este reporte muestra la dificultad que puede existir para establecer el diagnóstico del cálculo de la parótida. Creemos que el informe de este caso raro ayudará a los profesionales de la salud, reforzando la importancia de un diagnóstico adecuado basado en evaluaciones clínicas y de imágenes.

Resumo A formação de concreções calcificadas no ducto ou nas glândulas salivares é um distúrbio comum, mas os cálculos na parótida representam só uma pequena parte dos cálculos salivares. Nós descrevemos este raro caso de uma fístula cutânea associada a um cálculo salivar do lobo superficial da glândula parótida que foi removido sob anestesia local. Este reporte mostra a dificuldade que podemos ter na hora de diagnosticar o cálculo da parótida. Acreditamos que o relato desse caso raro ajudará os profissionais da saúde, reforçando a importância do diagnóstico adequado baseado em avaliações clínicas e por imagem.

Is Surgical Treatment Based on a 1-Step or 2-Step Protocol Effective in Managing the Odontogenic Keratocyst?

PURPOSE: The literature does not present any consensus on a uniform treatment plan for odontogenic keratocysts (OKCs) and does not provide adequate evidence for determining which modality is most effective in lowering morbidity or preventing recurrence. The purpose of this study was to compare the effectiveness of surgical treatment based on a 1- versus 2-step protocol. MATERIALS AND METHODS: The authors designed and implemented a retrospective cohort study and enrolled a sample of patients diagnosed with OKC from 1991 through 2018. The medical records of all cases were retrieved from files of the Oral and Maxillofacial Surgery Division of the Piracicaba Dental School (Piracicaba, Brazil). The predictor variable was treatment group (1- vs 2-step protocol). Statistical analysis was performed using Kaplan-Meier analysis, Mantel-Cox log-rank test, and proportional hazard regression analysis. RESULTS: The sample was composed of 72 patients (38 male) with a mean age of 40.72 years. Thirteen patients received 1-step treatment and 59 received 2-step treatment. The complex composed of the body, angle, and mandibular ramus was the site most frequently affected. In the individual Kaplan-Meier analysis for each presented variable only involved tooth was significant (P = .0128 by log-rank test), with the risk of relapse 4.23 times higher for the involved tooth than for the non-involved tooth. CONCLUSION: The 1- and 2-step protocols for treatment of OKCs are safe and appropriate as the first treatment option, offering a conservative and effective option with low morbidity. Treatment protocols associated with systematic monitoring promote a better quality of life for patients with low potential for complications.

Análisis Descriptivo y Cualitativo de Tres Software Gratuitos Usados para la Conversión de Formato DICOM para STL / Descriptive and Qualitative Analysis of Three Free Software Used to Convert From DICOM to STL Format

RESUMEN: Los exámenes imagenológicos tridimensionales en odontología son cada día mas frecuentes, contando también con algunas tecnologías gratuitas; el objetivo de este estudio fue analizar tres software gratuitos de conversión desde el formato DICOM al STL. Se evaluaron los programas computacionales 3DSlicer, InVesalius e ImageVis3D. La metodología empleada para evaluar fue basada en el modelo del proceso de evaluación de calidad, según la norma NBR ISO / IEC 9126-, incluyendo 6 observadores en la investigación. Se determinó que el programa más fácil de manipular en la etapa de segmentación, en la representación de volumen y en la conversión de archivos STL fue InVesalius, pero el programa más completo y preciso, para estas fases fue el software 3DSlider. Se puede concluir es necesario un entrenamiento adecuado para que la manipulación de estos programas sea lo más preciso posible.

ABSTRACT: The three-dimensional imaging in medical sciences nowadays is increasing and some of these technologies are free; the aim of this study was to analyze three free conversion software: 3DSlicer, InVesalius and ImageVis3D. The methodology used to evaluate the software was based on the model of the quality evaluation process, according to the standard NBR ISO/IEC 9126-1. It was observed that the easiest software to manipulate in the segmentation stage, in the representation of volume and in the conversion of STL (Standard Tessellation Language) files was InVesalius, but the most complete and precise software for these phases was the 3DSlider software. Thus, it was concluded that adequate training is necessary so that the handling of these three software is as accurate as possible.

Comparative evaluation of different fixation techniques for sagittal split ramus osteotomy in 10 mm advancements. Part two: Finite element analysis.

PURPOSE: To evaluate three rigid, stable fixation methods for sagittal split ramus osteotomy (SSRO), using finite element analysis. The hypothesis is that a customized miniplate presents better stress concentration and distribution. MATERIALS AND METHODS: A 3D model of a hemimandible was created, and a 10-mm-advancement SSRO was simulated and fixed as follows: 3-DCP group - one custom miniplate fixed by eight screws; 4-H2P group - two miniplates of four holes each, fixed by eight screws; and 6-H2P group - two miniplates of six holes each fixed by 12 screws. After a vertical loading of 100 N, the values for von Mises stress, modified von Mises stress, and maximum and minimum principal stresses were measured. RESULTS: The area of maximum principal stress was similar for the three groups - located in the upper miniplate, in the screw near the proximal segment osteotomy. The maximum von Mises stresses were 1580.4 MPa, 1005 MPa, and 977.56 MPa for the 3DCP, 4-H2P, and 6-H2P groups, respectively, showing an allowable displacement of 2.57 mm, 1.62 mm, and 1.52 mm for the 3DCP, 4-H2P, and 6-H2P groups, respectively. CONCLUSION: The customized miniplate did not present better stress distribution than two commonly used types of fixation. Fixation with two straight miniplates, either with four or six holes, offers adequate resistance for 10 mm linear advancements.

Comparative evaluation of different fixation techniques of the sagittal split ramus osteotomy in 10 mm advancements: Mechanical testing and screw insertion torque.

PURPOSE: To compare the mechanical characteristics of five techniques for the functionally stable fixation of simulated sagittal split ramus osteotomy with 10 mm of advancement and to evaluate the screw insertion torque. MATERIALS AND METHODS: Fifty polyurethane hemimandibles with sagittal split ramus osteotomy and containing an advancement of 10 mm fixed and distributed as follows: Customized 3D Plate Group: 1 customized 3D miniplate; 4-Hole Plate Group: 2 miniplates with 4 holes; 6-Hole Plate Group: 2 miniplates with 6 holes; Hybrid Group: 1 flat miniplate with 4 holes and 1 bicortical screw; and Bicortical Screw Group: 3 bicortical screws. We conducted a mechanical test using vertical linear loading with a displacement velocity of 1 mm/min on a universal testing machine and assessed the screw insertion torque using a digital torque wrench. RESULTS: The means of strength for the 1-, 3- and 5-mm displacements were determined by a one-way analysis of variance (ANOVA) followed by the post hoc Tukey test. Statistically significant differences were observed only for the 5-mm displacement (F = 3.36; p = 0.01). There was a difference between the 4-H2P and HG groups (p = 0.04). CONCLUSION: The customized miniplate, the fixation methods with three bicortical screws, or with two straight miniplates with either 4 or 6 holes, all offer a similar mechanical resistance suitable for fixation.

Toxina Botulínica para el Tratamiento de los Desórdenes Temporomandibulares / Botulinum Toxin for the Treatment of Temporomandibular Disorders

RESUMEN: Los Trastornos Temporomandibulares (TTM) consisten en un conjunto de condiciones patológicas que afectan la articulación temporomandibular (ATM), los músculos de la masticación y las estructuras asociadas. Estudios epidemiológicos estiman que 40 % a 75 % de la población adulta presenta por lo menos un signo de TTM, como ruido articular y 33 % por lo menos un síntoma, como dolor facial o en la ATM. La toxina botulínica (BoNT) es una neurotoxina producida por la bacteria anaerobia Clostridium botulinum, solo la toxina A y B son utilizadas en la práctica clínica después de la aprobación de la Food and Drug Administration en 1989 y 2000; actualmente continúan siendo utilizadas para tratar varias condiciones de dolor, incluyendo la espasticidad muscular, distonia, dolor de cabeza y dolor miofascial. Las propuestas del mecanismo de acción fueron sugeridas a mediados de 1950 manifestando que esta neurotoxina posee alta afinidad con la sinapsis colinérgicas, ocasionando un bloqueo en la liberación de acetilcolina de esos terminales nerviosos, sin alterar la conducción neural de las señales eléctricas o en la síntesis de almacenamiento de acetilcolina. La inyección intramuscular en dosis y localización apropiada, provoca denervación química parcial y disminución de la contractura, sin ocasionar parálisis completa a lo que se le atribuye ser un innovador y eficaz método de tratamiento para el dolor crónico asociada con hiperactividad de los músculos masticatorios. La toxina botulínica tipo A es ser una alternativa para el control de la sintomatología dolorosa presente en los TTMs de etiología miogénica. Los autores recomiendan realizar un correcto diagnóstico, ya que la indicación de este tipo de tratamiento con diagnósticos incorrectos lleva a resultados inciertos.

ABSTRACT: Temporomandibular Disorders (TMD) is a term that was used to describe a set of pathological conditions that affect temporomandibular joint (TMJ), muscles of mastication and associated structures. Epidemiological studies estimates that 40 % to 75 % of the adult population has at least one sign of TMD, such as joint noise and 33 % presented some symptom such as facial or joint pain. Botulinum toxin is a neurotoxin produced by the anaerobic bacterium Clostridium botulinum. There are two types of toxin (A and B) used in clinical practice that were approved by Food and Drug Administration in 1989 and 2000. These medications are in use to treat various diseases including muscle spasticity, dystonia, headache and myofascial pain. The mechanisms of action were suggested in the mid-1950s, this neurotoxin seems to have an action at cholinergic synapses, causing a block in the release of acetylcholine from the nerve terminals without altering the neural conduction of the electrical signals. The synthesis and storage of acetylcholine were preserved. Intramuscular injection in appropriate doses and location causes partial chemical denervation and decreased contracture, without causing complete paralysis of muscles. Due to this features, it has been considered an innovative and effective method to treat chronic pain associated with hyperactivity of masticatory muscles. The botulinum toxin type A appears to be an alternative method for pain control present in TMDs that have myogenic etiology. The authors recommend a correct diagnosis, since the indication of this type of treatment associated with an incorrect diagnosis leads to uncertain outcomes, creating false conclusions.

Condylar Hyperplasia in a Monozygotic Twin Girl: An Argument About Etiology.

The diagnosis of unilateral condylar hyperplasia (UCH) requires a combined assessment consisting of clinical, radiological, and histopathological examination. The etiology of this condition is unknown. The purpose of this study is to report a rare case of UCH in a monozygotic twin. A 15-year-old girl was referred to our department complaining of facial asymmetry and malocclusion. Computed tomography and single-photon emission computed tomography imaging reveal enlargement of the left condyle and condylar neck, and an increased uptake that was diagnosed as active UCH. During the investigation of family and co-twin facial profile, no cases of UCH were identified. From the case reported in this study, the authors raise a hypothesis that can exist some environmental factor that is related in the development of condylar hyperplasia given the occurrence of this disease in one of twins.

Quality of life of patients with facial prosthesis / Calidad de vida de los pacientes portadores de prótesis faciales

ABSTRACT. Objective: evaluate the quality of life and self-esteem of patients with facial deformities in the nasal, oculo-palpebral, and auricular areas using bucco-maxillofacial prostheses. Methods: descriptive study in users of facial prostheses who were rehabilitated at the dental clinic of the University Hospital of Brasilia in the period 2004-2011. The average age of patients was 63.8 years. The data collection instruments were the SF-36 questionnaire and a survey containing the Rosenberg Self-Esteem/EPM scale. Results: skin cancer was the predominant etiologic factor (n = 4). Most patients think that their deformity is visible to some degree (n = 4) and for three of them this fact impacts negatively the frequency to visit public places. The self-esteem scale yielded an average score of 4.6. In evaluating the quality of life by means of the SF-36 questionnaire, there were scores like pain (46.67) and emotional aspects (33.33). Conclusion: the results demonstrate the importance of conducting systematic followups to these patients. Most surveyed patients experienced an increase in quality of life, as well as a higher self-esteem, which can be explained by the functionality and aesthetics offered by the prosthesis. This study is part of an assessment program conducted with the intention of structuring multidisciplinary rehabilitation programs.

RESUMEN. Objetivo: evaluar la calidad de vida y la autoestima de los pacientes con deformidades faciales en la zona nasal, la zona óculopalpebral y la región auricular, portadores de prótesis bucomaxilofaciales. Métodos: estudio descriptivo en pacientes usuarios de prótesis faciales, los cuales fueron rehabilitados en la clínica odontológica del Hospital Universitario de Brasilia en el periodo 2004-2011. La edad media de los pacientes evaluados fue de 63,8 años. Como instrumentos de recolección de datos, en esta investigación se utilizaron el cuestionario SF-36 y una encuesta que contenía la Escala Visual de Autoestima de Rosenberg ̸EPM. Resultados: el cáncer de piel fue el factor etiológico predominante (n = 4). La mayoría de los pacientes consideró que su deformidad es visible en algún grado (n = 4), y para tres de ellos este hecho interfiere negativamente en la frecuencia de visitas a sitios públicos. En la escala de autoestima se obtuvo una puntuación media de 4,6. En la evaluación de la calidad de vida utilizando el cuestionario SF-36 se obtuvieron valores como dolor (46,67) y aspectos emocionales (33,33). Conclusión: los resultados demuestran la importancia de hacer un seguimiento sistemático a estos pacientes. En la mayoría de los pacientes encuestados se identificó un aumento en la calidad de vida, así como una mayor autoestima, lo cual puede explicarse por la funcionalidad y estética desempeñada por la prótesis. Esta es una propuesta de evaluación que se llevó a cabo con el fin de estructurar programas de rehabilitación multidisciplinar.

Aumento Gingival en Base a Ácido Hialurónico en Defectos Perimplantares y Periodontales. Análisis de una Serie de Casos / Gingival Increase Based on Hyaluronic Acid in Peri Implant and Periodontal Defects. A Case Series Analysis

RESUMEN: El ácido hialurónico ha sido empleado en diferentes áreas anatómicas, su aplicación para el rejuvenecimiento facial y en las lesiones de la articulación son conocidos; sin embargo, la aplicación en defectos periodontales y perimplantares tiene limitada información. El objetivo de esta investigación es mostrar los resultados clínicos de una serie de casos de sujetos con defectos periodontales menores tratados con la aplicación de ácido hialurónico. Se incluyeron 4 sujetos que presentaron espacios negros y recesiones gingivales en los que se aplicó el protocolo de instalación de ácido hialurónico al 0,2 % en diferentes momentos; el seguimiento clínico demostró eficiencia en la recuperación estética y estabilidad en los aumentos. Es posible concluir que esta técnica mínimamente invasiva es promisoria para tratar defectos periodontales y perimplantares menores.

ABSTRACT: Hyaluronic acid has been used in different anatomical areas, where its application and use for facial rejuvenation as well as joint injuries are known. However, information of its application in periodontal and peri implant defects is limited. The aim of this research is to show the clinical results of a case series in subjects with minor periodontal defects treated with the application of hyaluronic acid. Four subjects with black spaces and gingival recessions were included; the protocol for application of 0.2% hyaluronic acid was realized at different times; the clinical follow-up showed efficiency in the aesthetic recovery and stability in the increases. It is possible to conclude that this minimally invasive technique is promising to treat minor periodontal and peri implant defects.

Mechanical evaluation of the use of conventional and locking miniplate/screw systems used in sagittal split ramus osteotomy.

OBJECTIVES: The aim of this study was to compare the mechanical resistance of four different osteosyntheses modeled in two different sagittal split ramus osteotomy (SSRO) designs and to determine the linear loading in a universal testing machine. MATERIALS AND METHODS: An in vitro experiment was conducted with 40 polyurethane hemimandibles. The samples were divided into two groups based on osteotomy design; Group I, right angles between osteotomies and Group II, no right angles between osteotomies. In each group, the hemimandibles were distributed into four subgroups according to the osteosynthesis method, using one 4-hole 2.0 mm conventional or locking plate, with or without one bicortical screw with a length of 12.0 mm (hybrid technique). Each subgroup contained five samples and was subjected to a linear loading test in a universal testing machine. RESULTS: The peak load and peak displacement were compared for statistical significance using PASW Statistics 18.0 (IBM Co., USA). In general, there was no difference between the peak load and peak displacement related to osteotomy design. However, when the subgroups were compared, the osteotomy without right angles offered higher mechanical resistance when one conventional or locking 2.0 mm plate was used. One locking plate with one bicortical screw showed higher mechanical resistance (162.72±42.55 N), and these results were statistically significantly compared to one conventional plate with monocortical screws (P=0.016) and one locking plate with monocortical screws (P=0.012). The difference in peak displacement was not statistically significant based on osteotomy design or internal fixation system configuration. CONCLUSION: The placement of one bicortical screw in the distal region promoted better stabilization of SSRO. The osteotomy design did not influence the mechanical behavior of SSRO when the hybrid technique was applied.

Retention and Mechanical Behavior of Attachment Systems for Implant-Retained Auricular Prostheses.

OBJECTIVE: Auricular prostheses are artificial substitutes for facial defects. The retention of these has often been a problem. This study aimed to evaluate the mechanical behavior of 3 retained auricular prosthetic connections when submitted to a mechanical cycling test. MATERIALS AND METHODS: Twelve samples with installed implants were obtained and divided into 3 groups according to their retention system with 4 samples in each group. I: bar-clip system; II: magnet system; and III: ball/o-ring system. Each of samples was submitted to the pull-out test during 3240 cycles (f = 0.5 Hz) to determine its tensile strength. The mechanical cycling test was performed using the servo-hydraulic machine MTS 810-Flex Test 40 (Eden Prairie, MN) that had a 2.5 mm shift at a 10 mm/s velocity. The retaining strength for each of the samples was obtained at 7 intervals. RESULTS: The tensile strength for the group retained by the bar-clip system (29.60 N) was higher with statistically significant difference (P < 0.05) when compared with the group retained by the ball/o-ring system (9.41 N) and magnets system (8.61 N) for all periods assessed. The ball/o-ring system showed loss of retention during the fatigue test (Kruskal-Wallis, chi-squared = 17.28; P < 0.01). CONCLUSIONS: The evaluated systems showed a tensile strength compatible with the clinical use and no fractures of the components were observed.

Mesiodens: a case report / Mesiodens: reporte de caso

ABSTRACT Mesiodens are supernumerary teeth, commonly seen in the maxillary midline. Given their high frequency, dentist should be aware of the signs and symptoms of mesiodens and their appropriate treatment. This case report describes an 8-year-old girl with a radiographic image suggesting two unerupted mesiodens between the central incisors on the palate. The intraoral examination showed swelling in the anterior palatal region with no mucosa alteration. The supernumerary teeth were diagnosed by periapical radiograph and computed tomography. The objective of this study is to present the clinical importance and use of diagnostic images, such as periapical radiograph (Clark technique) or tomography.

RESUMEN. Un mesiodens es un diente supernumerario que comúnmente se presenta en la línea media maxilar. Dada la frecuencia con la que se presenta, el odontólogo general debe estar bien informado acerca de los signos y síntomas del mesiodens y del tratamiento adecuado. Este artículo relata el caso de una paciente de 8 años de edad, en cuyo examen radiográfico se observa una imagen sugestiva de dos mesiodens no erupcionados entre los incisivos centrales superiores. En la valoración intraoral se encontró una inflamación en la región palatina anterior, sin ninguna alteración en la mucosa. Los dientes supernumerarios se diagnostican mediante radiografía y tomografía computarizada. El objetivo de este trabajo es presentar la importancia clínica observada y la utilización de imágenes auxiliares para el diagnóstico, como la radiografía periapical (técnica de Clark) o la tomografía computarizada.

Pain control in third molar surgery / Control del dolor en cirugía de tercer molar

The sensation of pain at the surgical site may be increased and persist for long periods after the noxious stimulus has been removed. Post-operative pain from the extraction of impacted molar may cause serious discomfort to the patient resulting in considered moderate to severe in intensity. Analgesia for this surgical procedure is related to the use of nonsteroidal anti-inflammatory drugs, steroids, analgesics of central and peripheral actions used in combination or individually. The aim of this review is to show an update about the use and the physiological bases for indications of the analgesic therapy in third molar surgery.

La sensación de dolor en el sitio quirúrgico puede ser mayor y persistente por largos periodos de tiempo después de que el estímulo nocivo ha sido retirado. El dolor postoperatorio desde la extracción de un molar impactado puede causar molestias moderadas o severas en intensidad. La analgesia para estos procedimientos son relacionadas con el uso de fármacos antiinflamatorios no esteroidales, esteroides, analgésicos de acción central y periféricos utilizados en combinación o individualmente. El objetivo de esta revisión es mostrar una puesta al día en el uso y las bases fisiológicas para la indicación de terapia analgésica en cirugía de tercer molar.

Stability of the prosthetic screws of three types of craniofacial prostheses retention systems.

OBJECTIVES: This study aimed to evaluate the stability of prosthetic screws from three types of craniofacial prostheses retention systems (bar-clip, ball/O-ring, and magnet) when submitted to mechanical cycling. MATERIALS AND METHODS: Twelve models of acrylic resin were used with implants placed 20 mm from each other and separated into three groups: (1) bar-clip (Sistema INP, São Paulo, Brazil), (2) ball/O-ring (Sistema INP), and (3) magnet (Metalmag, São Paulo, Brazil), with four samples in each group. Each sample underwent a mechanical cycling removal and insertion test (f=0.5 Hz) to determine the torque and the detorque values of the retention screws. A servo-hydraulic MTS machine (810-Flextest 40; MTS Systems, Eden Prairie, MN, USA) was used to perform the cycling with 2.5 mm and a displacement of 10 mm/s. The screws of the retention systems received an initial torque of 30 Ncm and the torque values required for loosening the screw values were obtained in three cycles (1,080, 2,160, and 3,240). The screws were retorqued to 30 Ncm before each new cycle. RESULTS: The sample was composed of 24 screws grouped as follows: bar-clip (n=8), ball/O-ring (n=8), and magnet (n=8). There were significant differences between the groups, with greater detorque values observed in the ball/O-ring group when compared to the bar-clip and magnet groups for the first cycle. However, the detorque value was greater in the bar-clip group for the second cycle. CONCLUSION: The results of this study indicate that all prosthetic screws will loosen slightly after an initial tightening torque, also the bar-clip retention system demonstrated greater loosening of the screws when compared with ball/O-ring and magnet retention systems.