How many implants are needed for mandibular full-arch rehabilitation?

Aim: To analyze the stress distribution at the peri-implant bone tissue of mandible in full-arch implant-supported rehabilitation using a different number of implants as support. Methods: Three-dimensional finite element models of full-arch prosthesis with 3, 4 and 5 implants and those respective mandibular bone, screws and structure were built. ANSYS Workbench software was used to analyze the maximum and minimum principal stresses (quantitative analysis) and modified von Mises stress (qualitative analysis) in peri-implant bone tissue after vertical and oblique forces (100N) applied to the structure at the cantilever site (region of the first molars). Results: The peak of tensile stress values were at the bone tissue around to the distal implant in all models. The model with 3 implants presented the maximum principal stress, in the surrounding bone tissue, higher (~14%) than the other models. The difference of maximum principal stress for model with 4 and 5 implants was not relevant (~1%). The first medial implant of the model with 5 implants presented the lower (17%) stress values in bone than model with 3 implants. It was also not different from model with 4 implants. Conclusion: Three regular implants might present a slight higher chance of failure than rehabilitations with four or five implants. The use of four implants showed to be an adequate alternative to the use of classical five implants

Rotation axis of the maxillary molar and maximum tooth movement according to force direction

Aim: To evaluate the correlation between the maxillary molar rotation center and the direction of the maximum tooth movement according to the force direction using three-dimensional finite element analysis (3D-FEA) Methods: Computed tomography of a human tooth was used to build a finite element model, which comprised the cancellous and cortical bones, the periodontal ligament and the tooth. After applying lateral and posterior boundary conditions, a 1 N force was applied to the mesial and lingual faces of the maxillary molar to simulate buccal and distal tipping forces on the tooth. Results: The initial displacement of the maxillary first molar was greater for distal tipping than for buccal tipping. The rotation axis for distal tipping in this simulation was located on the furcation of the first molar. For buccal tipping this axis was on the cervical and middle third of the buccal roots of the maxillary first molar. Conclusions: The applied movement interferes in molars Cres location. Higher molar tipping is expected when distal movement is applied rather than buccal movement thanks to the close distance between Cres and location of the force applied to this movement.

Efficiency of occlusal splints on police officers with TMD

Aim: To evaluate of the effect of two different occlusal splints on police officers with TMD. Methods: Thirty police officers were selected based on Research Diagnostic Criteria for TMD and on clinical exams. Volunteers (ten per group) were distributed according to occlusal splints: group A - Control, group B - Michigan Occlusal Splint (MOS), and group C - Planas Appliance (PA). Experimental groups were analyzed using a visual analog pain scale (VAPS), subject to a clinical evaluation of temporomandibular joint. Bilateral surface electromyographic activities of anterior and posterior temporal, masseter and suprahyoid muscles were analyzed at rest and during clenching, before and after four weeks using the occlusal splints. Results: The left and right temporal and masseter muscles sensitivity decreased after using both splints. Pain symptoms increased for group A (Control) and decreased for group C. Conclusions: Planas Appliance was more efficient on pain reduction than the Michigan Occlusal Splint.

Bone Substitutes used in Dentistry / Sustitutos Óseos Utilizados en Odontología

Repair of bone defects resulting from trauma, tumor resections and infections is a medical and dental problem that needs a practical and low cost solution. To facilitate the repair several grafts or bone substitutes may be applied inside the defects. Biomaterials allow treatment, increase or replacement of any tissue, organ or function of the body. The aim of this study was to approach the advantages, disadvantages and main applications of bone substitutes used in reconstruction searched in dental practice. The manuscripts used in this literature review were searched in Medline (PubMed) and Scopus databases and based on manuscripts published from 1991 to 2012. After reading the titles and abstracts of the manuscripts, studies were selected because of their correlations with the aim of the current study. Bone tissue engineering has emerged as a new area of regenerative medicine and biomaterials and has an essential function concerning osteoconductive scaffold, osteogenic growth factors, and osteogenic cells. Based on literature available, a combination of advantageous properties of natural resorbable polymers and bioactive material in nanoscale appears to be more relevant for use in bone defects.

La reparación de defectos óseos que resultan de traumas, resección de tumores e infecciones son un problema médico y dental que necesitan una solución práctica y de bajo costo. Para facilitar la reparación, diversos injertos o sustitutos óseos pueden ser aplicados en el interior de los defectos. Los biomateriales permiten tratar, aumentar o sustituir algún tejido, órgano o función del cuerpo. El objetivo de este estudio fue acercarse a las ventajas, desventajas y principales aplicaciones de los sustitutos óseos utilizados para la reconstrucción en la práctica dental. Los manuscritos utilizados en esta revisión sistemática de la literatura se realizaron mediante la búsquedas en Medline (PubMed) y bases de datos Scopus, basada en manuscritos aparecidas entre 1991 y 2012. Después de leer los títulos y resúmenes de los manuscritos, los estudios fueron seleccionados debido a su correlación con el objetivo del presente estudio. Ingeniería de tejido óseo se ha convertido en una nueva área de la medicina regenerativa y biomateriales y tiene una función esencial en relación osteoconductivo andamio, factores de crecimiento osteogénicos, y las células osteogénicas. Basado en la literatura disponible, una combinación de propiedades ventajosas de polímeros reabsorbibles naturales y el material bioactivo en nanoescala que parece ser más relevante para su uso en defectos óseos.

Relations between the mandibular canal and I, II and III Angle classes in panoramic radiographs / Relaciones entre el canal mandibular y clases I, II y III de Angle en radiografías panorámicas

To prevent injury to the inferior alveolar nerve during dental procedures, knowledge of its anatomical location and course of the mandibular canal is imperative. The aim of this study was evaluate the location on panoramic radiographs of the mandibular canal in relation to the apices of the permanent mandibular molars and base mandible, and relate the type of mandibular canal with Angle classes I, II and III. We evaluated 748 panoramic radiographs distributed according to sex and occlusal class (Angle I, II and III) of fully dentate individuals, 18­51 age group. The radiographs were divided according to Angle classes based on cephalometric tracing, clinical data from the medical records of each individual and the analysis of of the maxillar and mandibular dental arches models. The same individuals had the mandibular canal bilaterally assessed, and classified according to their location relative to the root apices of the mandibular molars and mandible base. Measurements of the distance from the mandibular canal to the apices of the teeth and mandible base were made on the Software ImageLab2000®. The intra-observer reproducibility of measurements on radiographs was assessed using the coefficient of variation (p<0.0001). Data were submitted to Kruskal-Wallis test, on software BioEstat 5.0. There were statistically significant differences (Kruskal-Wallis test, p <0.0001) between the occlusal classes, with the type of mandibular canal. A larger number of canals types 2 and 3 in class III individuals than in others. In conclusion, the location of the mandibular canal presents morphological changes in relation to the apices of the permanent molars, and the mandibular base according to the Angle classes I, II and III.

Para evitar lesiones del nervio alveolar inferior durante los procedimientos odontológicos, el conocimiento de la localización anatómica y curso del canal mandibular (CM) es imprescindible. El objetivo fue evaluar la localización del CM sobre radiografías panorámicas en relación con los ápices de los molares mandibulares permanentes y la base mandibular, relacionando el tipo de CM con las clases I, II y III de Angle. Se evaluaron 748 radiografías panorámicas distribuidas según sexo y clase oclusal (I, II y III de Angle) en individuos totalmente dentados (edad entre 18-51 años). Las radiografías fueron divididas de acuerdo a las clases de Angle según su trazado cefalométrico, datos clínicos de los registros médicos de cada individuo y el análisis de modelos de sus arcos dentarios mandibulares y maxilares. En los individuos se evaluó el CM bilateralmente y se clasificó de acuerdo a su ubicación en relación con los ápices radiculares de los molares mandibulares y base mandibular. Las mediciones de distancia desde el CM a los ápices radiculares y base mandibular se hicieron con el programa ImageLab2000®. Se evaluó la reproducibilidad intra-observador de las mediciones en las radiografías usando el coeficiente de variación (p<0,0001). Los datos fueron sometidos a la prueba de Kruskal ­Wallis con el programa BioEstat 5.0. Se observaron diferencias estadísticamente significativas (prueba de Kruskal-Wallis, p<0,0001) entre las clases oclusales y el tipo de CM. Hubo mayor número de canales tipos 2 y 3 en los individuos clase III. La ubicación del canal mandibular presenta cambios morfológicos en relación con los ápices de molares permanentes y la base mandibular de acuerdo a las clases I, II y III de Angle.

The application of finite element analysis in the skull biomechanics and dentistry.

Empirical concepts describe the direction of the masticatory stress dissipation in the skull. The scientific evidence of the trajectories and the magnitude of stress dissipation can help in the diagnosis of the masticatory alterations and the planning of oral rehabilitation in the different areas of Dentistry. The Finite Element Analysis (FEA) is a tool that may reproduce complex structures with irregular geometries of natural and artificial tissues of the human body because it uses mathematical functions that enable the understanding of the craniofacial biomechanics. The aim of this study was to review the literature on the advantages and limitations of FEA in the skull biomechanics and Dentistry study. The keywords of the selected original research articles were: Finite element analysis, biomechanics, skull, Dentistry, teeth, and implant. The literature review was performed in the databases, PUBMED, MEDLINE and SCOPUS. The selected books and articles were between the years 1928 and 2010. The FEA is an assessment tool whose application in different areas of the Dentistry has gradually increased over the past 10 years, but its application in the analysis of the skull biomechanics is scarce. The main advantages of the FEA are the realistic mode of approach and the possibility of results being based on analysis of only one model. On the other hand, the main limitation of the FEA studies is the lack of anatomical details in the modeling phase of the craniofacial structures and the lack of information about the material properties.

Biomechanics of the human canine pillar based on its geometry using finite element analysis / Biomecánica del pilar canino en el cráneo humano basada en la geometría utilizando análisis de elementos finitos

This study evaluated the stress distribution based on the canine pillar geometry in human skull, using a finite element analysis. Computed tomography of human skull was used to build a finite element model, which was composed by all bony structures of canine pillar: canine eminence, canine fossa, frontal process of maxilla, glabellum and superciliary arch. A support on the bite contact of maxillary canine tooth and a resultant force of the masticatory muscles was applied in the simulation. Equivalent Von-mises and maximum principal stresses were analyzed along the structures that compose the canine pillar geometry. Von-mises stress presented high stress concentrated at the canine fossa and frontal process of maxilla. Maximum principal stress showed compression areas at the canine fossa and part of frontal process and tensile stress at canine eminence and part of the frontal process. In conclusion, the different stress areas means different force concentrations transmitted along the canine pillar geometry during a peak canine bite.

Este estudio evaluó la distribución de la tensión sobre la geometría del pilar canino en el cráneo humano, utilizando análisis de elementos finitos. Se usó la tomografía computarizada de cráneo humano para construir un modelo de elementos finitos compuesto por todas las estructuras óseas del pilar canino: eminencia canina, fosa canina, proceso frontal del maxilar, glabela y arco superciliar. Se aplicó en la simulación un soporte ubicado sobre el contacto de mordida del diente canino maxilar y una fuerza resultante de los músculos de la masticación. Tensiones Equivalentes de Von-Mises y tensiones principales máximas fueron analizadas a lo largo de las estructuras que componen la geometría de pilar canino. La tensión de Von-Mises fue alta y concentrada en la fosa canina y proceso frontal del maxilar. La tensión principal máxima mostró áreas de compresión en la fosa canina y parte del proceso frontal y la tensión de tracción en la eminencia canina y parte del proceso frontal. Las diferentes áreas de tensión significan diferentes concentraciones de tensiones transmitida a lo largo de la geometría del pilar canino durante una mordedura canina máxima.

Comparison of distance and symmetry in the mental foramen obtained in situ and in radiographic images of Brazilians / Comparação da distância e simetria dos forames mentonianos obtidos em loco e em imagens radiográficas na população brasileira

The precise location of the mental foramina is of paramount importance when using implantology to carry out oral rehabilitation procedures not affecting crucial anatomic structures. Panoramic radiography has become the imaging method of choice in many of these cases because of its lower cost and the fact that with it a general assessment of the maxillofacial complex can be made. This study set out to evaluate the distance between the mental foramina and the relationship between them and the mandibular base, and the posterior border of the mandible ramus, as well as the relationship between the bilateral mandibular foramina. The morphometric procedures were carried out by three examiners experienced in Dental Radiology, firstly on 58 human mandibles, with the aid of digital calipers and then on the respective panoramic radiographs of the mandibles, with Image J software, with and without the aid of artificial markers for delimitating the areas of interest. Using Friedman's statistical analysis, there were statistically significant differences between various measurements analyzed and compared to the gold standard, which points to the need to use more accurate imaging tests.

A localização precisa do forame mentoniano tornou-se uma necessidade premente para a execução de procedimentos de reabilitações orais, empregando a implantodontia, que não afetem estruturas anatômicas importantes, sendo a radiografia panorâmica o método de imagem de escolha em muitos desses casos por ter baixo custo e pela possibilidade de avaliação geral do complexo maxilo facial. Este trabalho teve como objetivo avaliar a distância entre os forames mentonianos e a sua relação com a base mandibular, borda posterior do ramo da mandíbula e a relação entre os forames mandibulares bilateralmente. As morfometrias foram realizadas por três experientes avaliadores em Radiologia Odontológica, primeiramente em 58 mandíbulas humanas, com o auxílio de paquímetro digital e depois nas respectivas radiografias panorâmicas das mandíbulas, com o software Image J, com e sem o auxílio de marcadores artificiais para delimitação das áreas de interesse. Por meio da utilização da análise estatística de Friedman, observaram-se diferenças estatísticas significativas em diversas medidas analisadas, quando comparadas ao padrão ouro, fato que demonstra a necessidade da utilização de exames por imagem mais precisos.

Stress distribution in human zygomatic pillar using three-dimensional finite element analysis / Distribución de la tensión en el pilar cigomático humano usando análisis de elementos finitos tridimensional

This paper aimed to analyze stress distribution in human zygomatic pillar during masseter muscle contraction using three-dimensional finite element analysis. A three-dimensional model and hemi facial skull were produced based on CT-scan data. An adult male skull with structural anatomy integrity was used as model. Muscles forces were applied at origin of elevator muscles and supports was applied at the occlusal surfaces at first and second molars to simulate a masticatory load and stimulate the zygomatic pillar. Supports were applied to the occlusal contacts. Symmetry conditions were placed at the mid-sagittal plane. For the top and back cutting plane, constraints were used. Equivalent Von-Mises Stress and Maximum Principal Stress analysis were performed from the stress fields along the zygomatic pillar. It was represented by stress concentration at the alveolar process, zygomatic bone, frontal and temporal process of zygomatic bone and superciliary arch. Stress line indicates distribution of stress from maxilla toward the frontal and temporal bone. The stresses occurred due to resultant occlusal forces is mainly supported by the zygomatic bone, non-uniformly distributed and predominantly through the zygomatic pillar. This study contributed to better understanding of stress distribution in zygomatic pillar to understand the influence of chewing on zygomatic pillar morphology and also be useful for clinical practice.

El objetivo de este artículo fue analizar la distribución de la tensión en el pilar cigomático humano durante la contracción del músculo masetero utilizando análisis de elementos finitos tridimensionales. Un modelo de tres dimensiones de dientes del hemicráneo facial fueron producidos sobre la base de datos de CT-scan. Se utilizó como modelo un cráneo adulto de sexo masculino con la integridad de la anatomía estructural. Fuerzas musculares se aplicaron en el origen de los ascensores de los músculos de la mandíbula y soportes se aplicaron a la superficie oclusal del primer y segundo molar para simular una carga masticatoria y estimular el pilar cigomático. Condiciones de simetría se colocaron en el plano mediano. Se utilizaron restricciones en los planos superior y posterior. El análisis de las tensiones equivalentes von-Mises y máximo director se realizó a través del campo de esfuerzos a lo largo del pilar cigomático. Fue representada la concentración de esfuerzos en el proceso alveolar, hueso cigomático, proceso frontal y temporal del hueso cigomático y el arco superciliar. La línea de tensión indica la distribución de la tensión del maxilar hacia el hueso frontal y temporal. Las tensiones se produjeron debido a las fuerzas oclusales resultantes, que se apoyan principalmente por el hueso cigomático, distribuidas de manera no uniforme y sobre todo a través del pilar cigomático. Este estudio ha contribuido a una mejor comprensión de la distribución de la tensión en el pilar cigomático para entender la influencia de la masticación sobre la morfología de este pilar y ser de utilidad en la práctica clínica.

Orthodontic Extrusion of the Upper Central Incisor: A Rare Case of Pulp Mummification / Extrusión Ortodóncica del Incisivo Central Superior: un Caso Raro de Momificación Pulpar

Due to its anatomical positioning, the central upper incisors are the most affected teeth when related to trauma injuries in the craniofacial region, among with nose traumas. In childhood, traumatic injury is most often caused by bicycle accidents, sports, recreational activities or falls. The aim of this report is to describe a treatment for intrusion of the left maxillary central incisor and the subsequent complications in an 8-year-old boy. Also, the report emphasizes the importance of careful long-term follow-up monitoring intruded permanent teeth. Pulp tissue, as other tissues in the human body, tends to change with traumas. Some of those changes are natural while others occur as result of injuries to the dentin-pulp complex such as caries lesions, periodontal disease, calcifications, as in the present report, or restorative dental procedures. Normally conducted endodontic treatment must take place to obtain maximal results, but only after the re-stabilization of the tooth.

Debido a su localización anatómica, los incisivos centrales superiores son los dientes más afectados cuando se refieren a las lesiones traumáticas de la región craneofacial, entre los traumas nasales. En la infancia, lesión traumática suele ser ocasionado por accidentes de bicicleta, deportes, actividades recreativas o caídas. El objetivo de este artículo es describir un tratamiento para la intrusión del incisivo central superior izquierdo y las complicaciones posteriores en un niño de 8 años de edad. Asimismo, el informe hace hincapié en la importancia de cuidado a largo plazo con un seguimiento intrusión dientes permanentes. Tejido de la pulpa, como otros tejidos en el cuerpo humano, tiende a cambiar con traumas. Algunos de estos cambios son naturales, mientras que otros se producen como consecuencia de las lesiones del complejo dentina-pulpa, como las lesiones de caries, enfermedad periodontal, calcificaciones, como en el presente informe, restauración o intervención dental. Tratamiento endodóntico a cabo normalmente deben tener lugar para obtener los máximos resultados, pero sólo después de la re-estabilización del diente.

Emissary foramens of the human skull: anatomical characteristics and its relations with clinical neurosurgery / Forámenes emisarios del cráneo humano: características anatómicas y sus relaciones con la neurocirugía clínica

The recognition of emissary foramens is important not only for understanding the regional neurovascular anatomy, but also to distinguish normal from potentially abnormal structures. Thus, the aim of this study was to review the literature on anatomical and clinical aspects of the mastoid, parietal and sphenoid emissary foramens. It was found that the emissary foramen presents importance in clinical practice because it acts as a route of spread of extracranial infection to the intracranial structures and also possible complications in neurosurgery, due to its influence in the performance of techniques such as radiofrequency rhizotomy for treatment of trigeminal neuralgia. The anatomical knowledge of the emissary foramens is important due to variability in their incidence in the human skull and its relation to the dura mater sinuses.

El reconocimiento de forámenes emisarios es importante no sólo para la comprensión de la anatomía neurovascular regional, sino también para distinguir lo normal a partir de estructuras potencialmente anormales. El objetivo de este estudio fue revisar la literatura sobre los aspectos anatómicos y clínicos del proceso mastoide, huesos parietal y esfenoides y forámenes emisarios. El foramen emisario adquiere importancia en la práctica clínica debido a que actúa como una vía de propagación de la infección extracraneal a las estructuras intracraneales, y también con las posibles complicaciones en neurocirugía, debido a su influencia en el desarrollo de técnicas como rizotomía por radiofrecuencia en el tratamiento de neuralgia del trigémino. El conocimiento anatómico de los forámenes emisarios es importante debido a la variabilidad en su incidencia en el cráneo humano y su relación con los senos de la duramadre.

Incidence of the mandibular accessory foramina in Brazilian population

In adults, the mandibular accessory foramina are variables and are located on the medial surface of the mandible in positions above or below of the mandibular foramen. The aim of this study was to evaluate the incidence of the mandibular accessory foramina in Brazilians human mandibles and discuss the clinical aspects related to the presence of these foramina. Were evaluated 222 mandibles, adults, irrespective of gender. Was observed that 27.93% and 43.24% of the mandibles presented at least one mandibular accessory foramina located on the medial surface in position below and above, respectively, of the mandibular foramen. Unilaterally, the mandibular accessory foramina were observed below and above of the mandibular foramen in 22.07% and 25.22%, of the mandibles, respectively, and 5.85% and 18.02% bilaterally, respectively. This study demonstrated that the incidence of mandibular accessory foramen in the Brazilian population is significant and should be considered in the planning and execution of procedures in several areas of dental clinical practice in order to avoid complications.

Incidence of retromolar foramen in human mandibles: ethnic and clinical aspects / Incidencia del foramen retromolar en mandibulas humanas: aspectos étnicos y clínicos

The retromolar foramen allows the passage of the neurovascular bundles that contribute to nutrition and innervation of the pulp and periodontium of the lower teeth. Knowledge of this anatomical variation may prevent complications in the anesthesia and surgical procedures in this area and serve as an anatomical landmark for ethnic identification. The aim of this study was to evaluate the impact of the retromolar foramen in human mandibles of adult Brazilians and discuss the clinical and ethnic related to the presence of this foramen. Were evaluated 222 human mandibles, dry, adults, Brazilians, independent of gender. The evaluation was performed by two examiners who standardized search from a previous anatomical study. The mandibles were analyzed: the presence of the retromolar foramen (bilateral or unilateral), the presence of the foramen on right and left sides, and the number of foramens present on each side. It was found that 59 had at least one mandible retromolar foramens resulting in an incidence of 26.58 percent The retromolar foramen was present unilaterally in 41 mandibles and 18 bilaterally, with incidences of 18.47 percent and 12.16 percent respectively. On the right side, the retromolar foramen was present in incidences of 16.22 percent and 18.92 percent respectively. The analysis of the right side of the mandibles revealed that 47.46 percent, 21.21 percent and 3.03 percent had one, two and three foramens, respectively. The left side showed 55.93 percent, 16.22 percent and 8.11 percent of the 222 mandibles with one, two and three retromolar foramens, respectively. The incidence of retromolar foramen in the Brazilian population is significant and should be considered in the planning and execution of procedures in several areas of clinical practice dentistry in order to avoid complications. Moreover, it was found that the incidence of retromolar foramen contributes to differentiation of ethnic groups in the area of forensic anthropology...

El foramen retromolar permite el paso de los haces neurovasculares que contribuyen a la nutrición y inervación de la pulpa y periodonto de los dientes mandibulares. Conocer sus variaciones anatómicas pueden prevenir complicaciones de la anestesia y procedimientos quirúrgicos, y servir de punto de referencia anatómico para la identificación étnica. El objetivo de este estudio fue evaluar el impacto del foramen retromolar en mandíbulas humanas de brasileños adultos y discutir la relación clínica y étnica de la presencia de este foramen. Se evaluaron 222 mandíbulas humanas secas de adultos brasileños, independiente del sexo. La evaluación fue efectuada por dos examinadores que realizaron búsquedas estándar de un estudio anatómico anterior. En las mandíbulas se examinaron: la presencia del foramen retromolar (bilateral o unilateral), lados (derecho e izquierdo), y el número de forámenes presentes en cada lado. En 59 mandíbulas se observó al menos un foramen retromolar, una incidencia del 26,58 por ciento. El foramen retromolar estuvo presente de manera unilateral en 41 mandíbulas, bilateralmente en 18, con una incidencia del 18,47 por ciento y 12,16 por ciento, respectivamente. En el lado derecho, el foramen retromolar estuvo presente en el 16,22 por ciento y 18,92 por ciento respectivamente. El análisis de la parte derecha de la mandíbula reveló que 47,46 por ciento, 21,21 por ciento y 3,03 por ciento tuvo uno, dos y tres forámenes, respectivamente. El lado izquierdo mostró 55,93 por ciento, 16,22 por ciento y 8,11 por ciento con uno, dos y tres forámenes retromolares, respectivamente. La incidencia del foramen retromolar en la población brasileña es significativo y se debe considerar en la planificación y ejecución de los procedimientos en varias áreas de la odontología clínica con el fin de evitar complicaciones. Por otra parte, se constató que la incidencia del foramen retromolar contribuye a la diferenciación de los grupos étnicos en el área de la...

Craniofacial morphometry for craniofacial implant / Morfometría craneofacial para implante craneofacial

Craniofacial implants are being increasingly used to treat patients with sequelae of oncological resections, trauma, and congenital deficiencies, among other issues. The aim of this investigation was to establish the minimum and maximum bone dimensions present in the most used places for the insertion of craniofacial implants. A descriptive study was designed analyzing 40 human skulls using cone-beam computed tomography; in the volumetric reconstruction the points most often used in clinical investigations for the insertion of implants were selected, representing the orbital, perinasal, zygomatic bone and periauricular regions, measuring the distance between the cortical bones on the sagittal, axial and coronal planes; comparisons between gender and with other investigations with a similar aim were also made. In the supraorbital area, values of 7.92+/-1.82 mm were found and in the lateral area values of 7.54+/-0.98 mm, allowing the placement of implants 5 or 6 mm in length. In the area of the zygomatic bone, dimensions of 10.4+/-2.35 mm were obtained, allowing the placement of implants 8 mm in length. In the periauricular area values were obtained of 2.93+/-0.55 mm in the superior region and 3.1+/-0.7 mm in the inferior region, whereas in the perinasal area implants 4 mm in length can be placed. We concluded that the craniomaxillofacial bone structure presents acceptable widths for the installation of implants; the periauricular region presents lower dimensions, with the possibility of intracranial communication in areas above the external auditory meatus...

Los implantes craneofaciales están siendo cada vez más utilizado para tratar a pacientes con secuelas de resecciones oncológicas, traumatismos, y deficiencias congénitas, entre otras. El objetivo de esta investigación fue establecer las dimensiones óseas mínimas y máximas presentes en los lugares más utilizados para la inserción de implantes craneofaciales. Se diseño un estudio descriptivo que analizó 40 cráneos humanos utilizando cono Tomografía computarizada Cone-Beam; en la reconstrucción volumétrica fueron seleccionados los puntos más utilizados en las investigaciones clínicas para la inserción de implantes, que representan la orbital, hueso perinasal, hueso cigomático y regiones periauriculares. La medición de la distancia entre los huesos corticales en los planos sagital, axial y coronal, y las comparaciones entre el sexo y otras investigaciones con el mismo objetivo fueron realizadas. En el área supraorbital, se encontraron valores de 7,92 +/- 1,82 mm y en las áreas laterales de 7,54 +/- 0,98 mm, lo que permite la colocación de implantes de 5 o 6 mm de longitud. En el área del hueso cigomático se obtuvieron,dimensiones de 10,4 +/- 2,35 mm, permitiendo la colocación de los implantes de 8 mm de longitud. En la región periauricular se obtuvieron valores de 2,93 +/- 0,55 mm en la región superior y 3,1 +/- 0,7 mm en la región inferior, mientras que en lo zona perinasal se puede colocar implantes de 4 mm de longitud. Llegamos a la conclusión de que la estructura de los huesos craneomaxilofaciales presenta anchos aceptables para la instalación de implantes; la región periauricular presenta menores dimensiones, con la posibilidad de comunicación intracraneal en zonas sobre el meato auditivo externo...

Comparación antropométrica entre mandíbulas de las poblaciones uruguaya y brasileña / Anthropometric comparison between mandibles from Uruguayan and Brazilian populations

Las mandíbulas humanas pertenecientes a la población uruguaya presentan ciertas diferencias anatómicas con las de la brasileña. Tal hecho parecería deberse a las particularidades raciales y étnicas de cada país. Este estudio examinó las características morfológicas de 100 mandíbulas de uruguayos y las cotejó con las correspondientes a idéntico número de piezas óseas de brasileños, por medio de trece mediciones estipuladas por Humphrey et al. (1999). Las variaciones significativas entre los valores promedios fueron determinadas mediante el test de Mann-Whitney (alfa=5 por ciento). Se constataron expresivas discrepancias entre algunas de las dimensiones analizadas, producto de las modificaciones de forma y estructura de las mandíbulas de ambos grupos. Las uruguayas exhibieron guarismos clara o ligeramente superiores en prácticamente todas las medidas realizadas, salvo en lo que respecta a la altura de la sínfisis (sutilmente mayores en sus homólogas brasileñas). Las divergencias más evidentes correspondieron a la altura de la incisura, altura de la rama y longitud mandibular, y las menos notorias al ancho mandibular, altura de la sínfisis y ancho bicoronoideo. Los factores que pueden haber inducido a las mismas resultan realmente profusos, incluyendo tanto a las adaptaciones funcionales del sistema estomatognático como a las biomecánicas, estimuladas por la diferente consistencia de la dieta, o la propia miscegenación.

The human mandibles belonging to Uruguayan population present some anatomic differences with those belonging to Brazilian population. This appears to be determined by racial and ethnic characteristics of each country. This study examined the morphological characteristics of 100 Uruguayan mandibles and compared them with similar number of Brazilian bones, using thirteen measurements stipulated by Humphrey et al. (1999). The significant variations in mean values were calculated by Mann-Whitney test (alpha=5 percent). Expressive discrepancies were observed between the two populations regarding some of analyzed dimensions. The Uruguayan mandibles showed higher values in almost all measurements when compared to the Brazilian ones, except for the mandibular symphysis height, which was lightly higher in Brazilian mandibles. Differences were observed in notch and ramus height, mandibular length, mandibular width, symphysis height and bicoronoid width. Several factors could be responsible for these morphological discrepancies, including functional and biomechanical adaptations of stomatognathic system, stimulated by different consistency of the diet or miscegenation.

Estudio morfométrico del seno maxilar mediante tomografías computadorizadas: evaluación de la reconstrucción total de piso sinusal / Morphometric study of maxillary sinus by computed tomography: assessment of sinus floor bone reconstruction

La rehabilitación con implantes dentales en maxila posterior es compleja debido a la presencia del seno maxilar con sus diferentes variaciones anatómicas; el objetivo de este trabajo fue determinar el volumen óseo intrasinusal necesario para realizar la instalación de uno o mas implantes dentarios sin invadir la membrana sinusal. En 22 cráneos fueron evaluados 40 senos maxilares mediante tomografías computadorizadas (TC) realizando mediciones en los cortes axiales, coronales y sagitales. Se clasificaron los senos maxilares según el remanente de hueso alveolar y se instalo un implante de forma virtual en el lugar del primer molar superior, mediante el software implant view. Con estas medidas volumétricas finales se estableció las indicaciones reconstructivas intra sinusales a partir de los sitios donantes intrabucales mas frecuentemente evaluados en la literatura mundial. El grupo I (1mm a 4mm de reborde alveolar remanente) presentaba déficit óseo de hasta 1,98 cm3, el grupo II (4mm a 7mm) presentaba déficit de 1,06cm3; el grupo III (7mm a 10mm) presentaba un déficit de 0,67 cm3; a partir de estos resultados podemos concluir que los sitios intrabucales pueden ser utilizados en la mayoría de los grupo estudiados, incluyendo las reconstrucciones bilaterales.

Rehabilitation with dental implants in posterior maxilla is difficult because of the presence of maxillary sinus with anatomical variations. The aim of this research was to evaluate the sinus volume to install one or more implants without invading the sinus membrane. Forty (40) maxillary sinuses were evaluated in 22 skulls by computed tomography measuring in the axial, coronal and sagittal slice. The sinus were classified according to the remaining alveolar bone and a dental implant in the place of the upper first molar was virtually installed by implant view software. With this final volumetric measurement the surgical indications were established for inlay reconstruction from intra oral donor sites frequently evaluated in world literature. Group I (1mm to 4mm of alveolar ridge) showed a bone deficit of 1.98 cm3, group II (4mm to 7mm) showed a deficit of 1.06 cm3; group III (7mm to 10mm) showed a 0.67 cm3 deficit. In view of these results we concluded that intra oral donor site can be used for the three study groups and in some cases in bilateral reconstruction.

Use of homologous bone grafts in maxillary sinus lifting / Uso de injertos de hueso homólogo en la elevación del seno maxilar

Homologous bone has been considered a viable alternative in bone reconstruction in the posterior maxillary area to perform surgeries for the maxillary sinus lifting. The aim of this study was to perform a literature review about the advantages and risks inherent in the use of homologous bone graft coming from the tissue bank to perform the surgery for maxillary sinus lifting. A literature review was conducted on MEDLINE (PubMed), Scielo, Scopus and Lilacs, and based on manuscripts and books published from 1980 to 2010. After reading the titles and abstracts of the manuscripts, 69 studies were selected because of their correlations with the aim of the current study. The use of homologous grafts from bone banks showed greater osteogenic potential and a slow remodeling least compared to other grafts to increase the volume of the posterior bone of the maxilla in surgery for maxillary sinus lifting.

De hueso homólogo se ha considerado una alternativa viable en la reconstrucción ósea en la zona posterior del maxilar para cirugías de la elevación del seno maxilar. El objetivo de este estudio fue el desempeño de una revisión de la literatura sobre las ventajas y riesgos inherentes en el uso de injerto de hueso homólogo proveniente del banco de tejidos para la cirugía de elevación del seno maxilar. Una revisión de la literatura se hizo en MEDLINE (PubMed), Scielo, Scopus y Lilacs, y en base a manuscritos y libros publicados desde 1980 hasta 2010. Después de leer los títulos y resúmenes de los manuscritos, 69 estudios fueron seleccionados debido a su correlación con el objetivo de este estudio. El uso de injertos homólogos de los bancos de hueso mostró un mayor potencial osteogénico y una remodelación lento por lo menos en comparación con otros injertos para aumentar el volumen del hueso posterior del maxilar superior en la cirugía de elevación del seno maxilar.

Short implants in oral rehabilitation

Introduction and objective: The placement of short dental implants is used as an alternative treatment modality to bone grafting procedures. The aim of this study was to discuss, through a literature review, the features, indications and biomechanical aspects of short implants, as well as to report the clinical factors that influence on their indication. Literature review and conclusion: It was found that short implants osseointegration can be compromised by risk factors that must be controlled to achieve treatment success. In conclusion, the main indication of short implants is to avoid an invasive surgery at atrophic areas of maxilla and mandible. Furthermore, implant design associated with surface treatment are factors that compensate its short length.

Estudio morfométrico de la región orbitaria para la instalación de implantes craneofaciales / Morphometric study of orbital region for craneofacial implant applications

El objetivo de esta investigación es establecer las relaciones morfométricas presentes en las regiones periorbitarias utilizadas para la instalación de implantes craneofaciales. Se diseñó un estudio descriptivo utilizando 40 cráneos humanos de entre 20 y 60 años del Laboratorio de Anatomía del Departamento de Morfología de la Facultad de Odontología de Piracicaba de la Universidad Estadual de Campinas. Fueron realizadas tomografías volumétricas cone beam y a partir de la reconstrucción virtual se precisaron los puntos de análisis, basados en la literatura científica, tanto clínica como anatómica de la región. Se realizaron divisiones de la órbita respetando distancias mínimas y reparos anatómicos como el seno frontal y seno maxilar. En las mediciones realizadas, se observó que el área supraorbitaria presentaba una distancia ósea sagital de 8,14mm +/- 1,91mm, el reborde infraorbitario de 7mm +/- 1,71mm y el área lateral de órbita un promedio de 7,91mm +/- 1,15mm. Considerando que los implantes de mayor dimensión son de 6mm, la instalación de implantes en estas regiones está totalmente asegurada en términos de requerimientos de cantidad ósea regional.

The aim of this research was to study the morphometric relation present in periorbital region, used in the installation of craniofacial implants. A descriptive study was carried out using 40 skulls between 20 and 60 years of age from the Laboratório de Anatomia do Departamento de Morfologia da Facultade de Odontologia de Piracicaba da Universidade Estadual de Campinas. Volumetric tomography with cone beam technique was used along with virtual reconstruction, with the point of analysis being selected based on the clinical and anatomical scientific literature. Orbital division was realized with minimal distance from the frontal and maxillary sinus. During measurement it was observed that the superior orbital rim presented a sagittal bone distance of 8.14mm +/- 1.91 mm; inferior orbital rim of 7mm +/- 1.71 mm, and the lateral orbital presented an average of 7.91 mm +/- 1.15 mm, considering that craniofacial implants present up to 6 mm in length, the installation of implants in this area is considered safe in terms of regional bone quantity requirements.

Comportamento dos músculos cervicais em indivíduos com fala esofágica e laringe artificial / Behavior of cervical muscles in individuals with esophageal speech and artificial larynx

OBJETIVO: avaliar através da eletromiografia de superfície o comportamento dos músculos esternocleidomastóideo e paraespinhais cervicais bilateralmente em pacientes que se comunicam por meio da fala esofágica e laringe artificial, para determinar se o tipo de voz utilizada altera o comportamento dos músculos cervicais. MÉTODOS: foram avaliados dez voluntários (duas mulheres e oito homens), idade média de 49,7 anos, com laringectomia total, tempo de pós-operatório médio de 2,6 anos, com limitação dos movimentos do pescoço, divididos em dois grupos: grupo 1: cinco voluntários (laringe artificial); grupo 2: cinco voluntários (voz esofágica); grupo 3 controle (sete voluntários). RESULTADOS: na fonação não houve alteração no padrão de ativação muscular dos indivíduos que utilizam a voz esofágica e a laringe artificial, com relação ao grupo controle. No entanto, na condição de repouso houve diferença significativa, comparando-se os valores médios de Root Mean Square dos grupos 1 e 2 com o grupo 3, para o músculo esternocleidomastóideo direito e para os músculos paraespinhais cervicais direito. CONCLUSÃO: o tipo de opção vocal não interferiu no padrão de ativação muscular durante a fonação, bem como não existiu diferença no padrão de ativação muscular na fonação dos voluntários quando comparados a indivíduos sem intercorrências no aparelho fonador.

PURPOSE: to evaluate by the surface electromyography the behavior of the sternocleidomastoid and cervical paraspinalis muscles, bilaterally in patients who use esofagic and artificial larynx as alternative to talk and to determine if these conditions modify the cervical muscles behavior. METHODS: ten volunteers were evaluated (two women, eight men), with average age: 49. 7 years, with total laryngectomy, average time of postoperative: 2.6 years, with neck movements limitation, divided in two groups: group 1 with five volunteers (artificial larynx); group 2 with five volunteers (esofagic voice); and group 3 control (seven volunteers). RESULTS: there was no significant difference in the muscular activation pattern during phonation in individuals with esofagic voice and the artificial larynx compared to the control group, however, in the rest condition, there was a significant difference comparing the average values of Root Mean Square (RMS) of groups 1 and 2 with group 3, for the right sternocleidomastoid muscle and the right cervical paraspinalis muscles. CONCLUSION: the vocal option did not interfere on the muscular activation pattern during the phonation, as well as there was no difference in the muscular activation pattern comparing the experimental groups with the control group.