Dental Anatomy and Nomenclature for the Radiologist.

Head and neck imaging studies frequently encompass the oral cavity and human dentition. Given the relatively wide prevalence of dental disease, the likelihood of detecting incidental dental pathology is high. This article provides an overview of dental terminology, anatomy, restorations, and associated computed tomography imaging artifacts necessary to more effectively interpret and communicate findings related to teeth.

A review of pediatric radiology.

In most dental schools, the focus is on teaching students how to treat adults, with little emphasis placed on treating children. The goal of this article is to review some basic concepts in pediatric radiology to help general practitioners have a better understanding of when to take radiographs on children, which radiographs should be taken, what to look for when examining the radiographs and possible ways to treat the problems diagnosed from the radiographs.

Criterio de selección en diagnóstico por imágenes / Selection criteria in imaging diagnosis

Las radiografías odontológicas son herramientas esenciales para el diagnóstico bucomaxilofacial: panorámica (PAN), periapical (PER) y bite-wing (BW), las cuales se pueden utilizar en forma individual o combinadas entre sí (American Dental Assoc. Council on Scientific Affairs, JADA, 2006). Aunque las dosis de radiación utilizadas por los odontólogos no son altas, la cantidad de exposiciones a que son sometidos los pacientes pueden ser excesivas. En USA y en la UE se han publicado guías sobre portección radiológica dental (BOE, Reegulations on Ionizing Radiation Protection in State Oficial Bulletin, 2001; Brown, 1980; Oficial Journal of the European Communities, 1996; European Guidelines on Radiation Protection in Dental Radiology, 2004), estableciendo el uso de las radiografías para evitar irradiaciones rutinarias innecesarias.

Content-based access to oral and maxillofacial radiographs.

OBJECTIVES: Content-based access (CBA) to medical image archives, i.e. data retrieval by means of image-based numerical features computed automatically, has capabilities to improve diagnostics, research and education. In this study, the applicability of CBA methods in dentomaxillofacial radiology is evaluated. METHODS: Recent research has discovered numerical features that were successfully applied for an automatic categorization of radiographs. In our experiments, oral and maxillofacial radiographs were obtained from the day-to-day routine of a university hospital and labelled by an experienced dental radiologist regarding the technique and direction of imaging, as well as the displayed anatomy and biosystem. In total, 2000 radiographs of 71 classes with at least 10 samples per class were analysed. A combination of co-occurrence-based texture features and correlation-based similarity measures was used in leaving-one-out experiments for automatic classification. The impact of automatic detection and separation of multi-field images and automatic separability of biosystems were analysed. RESULTS: Automatic categorization yielded error rates of 23.20%, 7.95% and 4.40% with respect to a correct match within the first, fifth and tenth best returns. These figures improved to 23.05%, 7.00%, 4.20%, and 20.05%, 5.65% and 3.25% if automatic decomposition was applied and the classifier was optimized to the dentomaxillofacial imagery, respectively. The dentulous and implant systems were difficult to distinguish. Experiments on non-dental radiographs (10,000 images of 57 classes) yielded 12.6%, 5.6% and 3.6%. CONCLUSION: Using the same numerical features as in medical radiology, oral and maxillofacial radiographs can be reliably indexed by global texture features for CBA and data mining.

Posicionamento condilar em pacientes classes I, II e III de Angle: avaliação através de radiografias transcranianas / Condilar positioning in patients with malocclusions of Angle class I, II and III: evaluation through transcranial x-rays

O propósito deste trabalho foi comparar a posição da cabeça da mandíbula na cavidade articular em pacientes portadores de más oclusões classes I, II e III de Angle. Foram utilizadas radiografias transcranianas das articulações temporomandibulares de 50 pacientes assintomáticos, dos gêneros masculino e feminino, com idade entre 18 e 25 anos, encaminhados para tratamento odontológico na Clínica Integrada da UNICOR- Três Corações. Para comparar valores dos espaços articulares anterior, superior e posterior tanto em máxima interscupidação quanto em repouso para os lados direito e esquerdo, foi utilizado o teste de Kruskal-Wallis (p<0,05). Os resultados permitiram concluir que não houve diferença estatisticamente significante entre os lados direito e esquerdo para a maioria das medidas dos espaços articulares em máxima intercuspidação e em repouso, entre os tipos de más oclusões. Em relação ao deslocamento condilar, nos casos de classe I, ocorreu posicionamento condilar concêntrico em maior proporção, nos casos de classe II houve predominância da posição posteriorizada, e na classe III os côndilos apresentaram maior tendência para deslocamento anterior. Concluiu-se que o posicionamento condilar na cavidade articular varia significativamente entre os tipos de maloclusão de Angle, sendo a radiografia transcraniana um exame complementar que pode contribuir para o diagnóstico das maloclusões, bem como das alterações da ATM

Radiation exposure in dental radiology: a 1998 nationwide survey in Switzerland.

OBJECTIVES: To measure the frequencies of dental radiological examinations in Switzerland and to determine the associated collective radiation doses. METHODS: To evaluate the frequencies, a sample of 376 dental practitioners and other institutions performing dental radiology were requested to fill in questionnaires designed to measure, amongst others, frequencies of dental radiodiagnoses according to type of examination, patient age and gender, dental specialty and type of surgery. The associated collective radiation doses were determined by multiplying the relevant frequencies with dose estimates obtained from recent measurements and calculations. RESULTS: The total number of dental examinations performed in Switzerland in 1998 was 4.1 million (581 per 1000 population). Periapical, bitewing and panoramic radiographs were the most frequent types of dental examinations. The collective dose associated with dental radiology was 71 person.Sv. This amounts to an annual average effective dose to the population of 10 muSv per caput, which is in agreement with the figures reported for countries of similar healthcare level. Various features such as the age distribution of the radiographed patients, the forms of collimators used, film consumption and the use of digital imaging systems are presented. CONCLUSIONS: Several recommendations for dose reduction are made. These include the re-evaluation of the patterns and justification for prescribing some particular types of dental examinations as well as the avoidance of unnecessary irradiation by the use of rectangular collimation and high sensitivity F-speed films.

Patient characteristics associated with receipt of dental radiographic procedures during a 48-month population-based study of dentate adults.

OBJECTIVE: The objective was to test hypotheses that patient characteristics are associated with receipt of specific types of radiographic procedures. STUDY DESIGN: The Florida Dental Care Study was a prospective cohort study of dentate adults. RESULTS: From 19% to 59% of participants received a full-mouth series, panoramic, bitewing, or periapical radiograph(s), depending on procedure type. Receipt varied with reason(s) for dental visit(s), baseline clinical condition, race, approach to care (problem-oriented or regular dental attender), and socioeconomic status. CONCLUSION: These findings underscore the distinction between what dentists hypothetically would prescribe, compared to what is actually received, receipt that results from the interaction between dentist recommendations and what patients will accept and pay for. Blacks and lower-income persons received dental radiograph types that were consistent with less comprehensive dental treatment, even with entry into the dental care system, reason(s) for incident dental visit(s), baseline clinical status, and regular versus problem-oriented attendance taken into account.

Comparison of radiation levels from computed tomography and conventional dental radiographs.

BACKGROUND: With the increasing use of computed tomography (CT) in oral diagnosis and treatment planning, concern has been expressed about the high levels of radiation used, and the associated risks. OBJECTIVES: The purpose of this study was to compare the radiation doses of facial CT scans with the radiation doses taking a lateral cephalometric radiograph, a panoramic radiograph (OPG), an occlusal film, and an intra-oral periapical radiograph. METHODS: An Alderson-Rando anthropomorphic phantom head was used for the analysis. Thirty-six lithium fluoride thermoluminescent dosimeters were placed in the phantom head in locations representing radiosensitive sites. Standard facial CT scans and conventional radiographs (lateral cephalometric, OPG, maxillary occlusal, intra-oral periapical) were then taken of the phantom head. RESULTS: The following radiation doses were measured: maxillo-mandibular CT scan, 2.1 mSv; maxillary CT scan, 1.40 mSv; mandibular CT scan, 1.32 mSv; lateral cephalometric radiograph, 0.005 mSv; OPG, 0.010 mSv; maxillary occlusal, 0.007 mSv; intra-oral periapical radiograph, 0.005 mSv. CONCLUSIONS: CT scans produce significantly more ionising radiation than conventional radiographs. This factor should be taken into account when considering a CT scan as an alternative to a survey with conventional radiographs. While CT scans offer many advantages over conventional radiography the high radiation dose to patients, and the cost of this procedure should be considered.

Adenoma pleomorfo intra-óseo; presentación de un caso y revisión bibliográfica / Intraosseous pleomorphic adenoma: case report and review of the literature central pleomorphic adenoma of the maxilla

Se presenta un caso de adenoma pleomorfo intra-óseo, localizado en el maxilar superior (región paramediana izquierda), con una evolución de aproximadamente un año, en un paciente del sexo femenino, de 31 años de edad. El adenoma pleomorfo es el tumor más común de las glándulas salivales, afectando principalmente a la parótida. La ubicación intraoral más frecuente de este tumor es en el paladar. En el presente caso está situado intra-óseamente, (localización rara) con un posible origen a partir de restos epiteliales glandulares atrapados en la embriogénesis. La revisión bibliográfica permitió identificar 142 casos de localización intra-ósea, (24 por ciento en el maxilar superior). Fue observada una pequeña predilección por el sexo femenino (56 por ciento), estando el 55 por ciento de los casos en edades comprendidas entre la 5ª y 7ª décadas de vida, siendo el 94 por ciento de estos tumores, malignos, con especial preferencia del carcinoma mucoepidermoide (65 por ciento). Los adenomas pleomorfos intra-óseos son raros, ocupando el 6º. Dentro de estos, el que afecta al maxilar superior ocupa el 2º lugar, según la bibliografía revisada. De los 5 casos previamente presentados la media de edad fue de 58,8 años (AU)

Repercusiones de la corrección quirúrgicadel prognatismo inferior en la vía aérea / Repercussion of surgical correction of mandibular prognatism on the airways

Se muestra un caso clínico de Clase III tratado en forma convencional mediante ortodoncia y cirugía; a través de él se hace énfasis en la importancia de la vía aérea superior, la cual puede verse afectada como consecuencia de la reducción quirúrgica del maxilar inferior. (AU)

Cirugía periapical de 29 dientes. Comparación entre técnica convencional, microsierra y uso de ultrasonidos / Peripical surgery of 29 teeth. A comparison of convencional techique, microsaw and ultrasound

Objetivos: Evaluar clínica y radiológicamente los resultados obtenidos en cirugía periapical mediante la utilización de diferentes técnicas. Material y Métodos: Se han analizado 29 dientes unirradiculares (en 29 pacientes) que presentaban patología periapical tras un tratamiento endodóntico correcto. Se han formado tres grupos: A) 10 pacientes en los que la osteotomía, apicectomía y preparación cavitaria se hicieron con instrumental rotatorio; B) 10 pacientes a los que se les realizó la osteotomía y la resección apical con instrumental rotatorio, y la preparación retrógrada con ultrasonidos; y C) con 9 pacientes en los que se utilizó la microsierra para la osteotomía y los ultrasonidos para preparar la cavidad en la raíz. Todos los casos fueron obturados con IRMO. Se realizaron controles clínicos y radiográficos a los 10 días, 1 mes, 6 meses y 1 año. Resultados: Al término del estudio, se obtuvo un éxito clínico en 17 pacientes (58,6 por ciento), que no presentaron sintomatología, y 16 (55,2 por ciento) mostraron una imagen radiográfica con regeneración ósea completa (curación completa). El éxito clínico al año fue para el grupo B del 70 por ciento, en el grupo C del 66,7 por ciento y del 40 por ciento en el grupo A. La completa curación radiográfica tuvo lugar en un 30 por ciento en el grupo A, en el 60 por ciento en el B y en el 77,8 por ciento en el C. El grupo A presentó 3 fracasos y 2 en el C, no existió ningún fracaso en el grupo B. Conclusiones: La técnica más satisfactoria fue cuando se usaron los ultrasonidos para la preparación de la cavidad (AU)

Machine classification of dental images with visual search.

RATIONALE AND OBJECTIVES: The authors performed this study to assess the performance of a computer-based classification system that uses gaze locations of observers to define the subspace for machine learning. MATERIALS AND METHODS: Thirty-two dental radiographs were classified by an expert viewer into four categories of disease of the periapical region: no disease (normal tooth), mild disease (widened periodontal ligament space), moderate disease (destruction of the lamina dura), and severe disease (resorption of bone in the periapical area). There were eight images in each category. Six observers independently viewed the images while their eye gaze position was recorded. They then classified the images into one of the four categories. A sample of image space was used as input to a machine learning routine to develop a machine classifier. Sample space was determined with three techniques: visual gaze, random selection, and constrained random selection. K analyses were used to compare classification accuracies with the three sampling techniques. RESULTS: With use of the expert classification as a standard of reference, observers classified images with 57% accuracy, and the machine classified images with 84% accuracy by using the same gaze-selected features and image space. Results of kappa analyses revealed mean values of 0.78 for gaze-selected sampling, 0.69 for random sampling, 0.68 for constrained random selection, and 0.44 for observers. The use of sample space selected with the visual gaze technique was superior to that selected with both random-selection techniques and by the observers. CONCLUSION: Machine classification of dental images improves the accuracy of individual observers using gaze-selected image space.