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Papers by Juan Fernando Oyarzo

Acta odontológica venezolana

Dentomaxillofacial Radiology, 2008

A 28-year-old woman presented with a history of clicking and mandibular clenching. She was studie... more A 28-year-old woman presented with a history of clicking and mandibular clenching. She was studied clinically and with axial and coronal CT. The patient was going through a tense emotional period and reported tightening of her teeth (clenching); she was under psychological and neurological treatment for depression including pharmacological therapy. She presented slight pain only at maximum mouth opening at the right temporomandibular joint (TMJ) and in the lateral pole on palpation; there was no coincidence between initial and maximal interocclusal contacts because of premature dental contacts. She showed occlusal group function in the right side and canine guidance in the left side with a right contact of balance, local muscular pain in the right deep masseter muscle and in the superior and middle portion of the right trapezium on palpation. On CT, a spherical area of 3 mm diameter with an average density of 2647 HU (SD¡4.7) was found in the upper and posterior area of the lower space of the right TMJ, together with a thicker lower synovial tissue. This observation was confirmed by MRI. Like other joints, the TMJ could present vacuum phenomenon images inside synovial tissue in the presence of degenerative disease. It is important for radiologists to recognize this rare entity.

El objetivo de este estudio in vitro fue describir la superficie coronaria y radicular alrededor ... more El objetivo de este estudio in vitro fue describir la superficie coronaria y radicular alrededor de restauraciones de resina compuesta posterior a su pulido. Materiales y metodo: se realizaron 50 restauraciones estandarizadas sobre la superficie coronaria y 50 sobre la superficie radicular de dientes extraidos por indicacion ortodoncica. Las cavidades se prepararon utilizando fresas cilindricas de carbide (Meissinger®) con alta velocidad (Champion Dental Products Inc) bajo irrigacion y fueron restauradas con resina compuesta hibrida (Filtek® Z 250, 3M®). Fueron separadas aleatoriamente en 5 grupos de 10 restauraciones coronarias y 10 radiculares. Cada grupo fue pulido utilizando un sistema diferente, siguiendo las indicaciones del fabricante. Grupo 1 (PB): Piedras de Arkansas (Dedeco). Grupo 2 (PD): piedras de diamante finas, extrafinas y ultrafinas (Diatech®). Grupo 3 (DOA): discos de oxido de aluminio (Sof lex®, 3M®). Grupo 4 (PG): puntas Enhance ® (Dentsply®). Grupo 5 (FCT): fresas de carburo tungsteno de 16 y 30 cuchillo (Komet®). 10 dientes sin tratamiento se dejaron como grupo control (Grupo 6). Todas las muestras fueron observadas y fotografiadas mediante microscopia electronica de barrido (TEAC Siemens®) y microscopia optica (Carl Zeiss®). Las imagenes se compararon con las del grupo control. Resultados: la comparacion de las microfotografias de los grupos tratados con las del grupo control mostro cambios en la corona y en la raiz en los grupos 1, 2, 3 y 4. En la corona se observo una perdida de las caracteristicas superficiales del esmalte y en la raiz una perdida del cemento y exposicion de dentina. En el grupo 5 algunas muestras presentaron modificacion de la estructura superficial normal y otras no. Conclusion: los 5 sistemas de pulido de resinas compuestas analizados en este estudio modificaron la superficie del esmalte y el cemento. Palabras clave: Sistemas de pulido , Resina compuesta, Meb ABSTRACT The aim of this IN VITRO study was to describe the crown and root surface surrounding composite restorations, after polishing procedures. Materials and Methods: 50 standardized restorations were made over the crown surface and 50 over the root surface of teeth extracted by orthodontics indications. The cavities were prepared using cylindrical carbide burs (Meissinger ) under water irrigation with a high speed hand piece (Champion Dental Products Inc) and restored with hybrid composite (Filtek Z250®, 3M®). They were randomized and separated into five groups of 10 restorations either in crown and root. Each group was polished using different systems, according to manufacturer's instructions. Group 1(PB): Arkansas Stone (Dedeco). Group 2 (PD): Fine, extrafine and ultrafine Diamond Burs (Diatech®). Group 3 (DOA): Aluminum Oxide Discs (Sof lex® 3M®). Group 4 (PG): Enhance® Points (Dentsply®). Group 5 (FCT): 16 and 30 blades Tungsten Carbide Burs (Komet®). 10 teeth without treatment were used as control group (Group 6). All samples were analyzed and photographed by SEM (TEAC Siemens®), and Optical microscope (Carl Zeiss®). The images were compared with control group. Results: The comparison of the microphotography with control group showed changes in both crown and root surfaces in groups 1, 2, 3 and 4. It was seen a loss of the enamel superficial characteristics, in crown surfaces and a loss of the cementum and exposure of dentin in root. In group 5 some specimens resulted in a modification of normal tooth surface characteristics and in others there were no changes. Conclusions: The five composites polishing systems analyzed in this study resulted in enamel and cementum modification.

Medwave

Temporomandibular disorders (TMDs) are complex multi-system disorders for which common traditiona... more Temporomandibular disorders (TMDs) are complex multi-system disorders for which common traditional dental-centric approaches to research and care unfortunately continue to prevail. A committee appointed by the National Academies of Sciences, Engineering and Medicine (NAM) of the United States of America summarized important recommendations regarding the urgent need to transform, from the predominantly biomedical model, the research, professional education/training, and patient care for TMDs into the biopsychosocial model that is standard in the rest of pain medicine. The release of the Consensus Study Report identifies eleven short-term and long-term recommendations regarding gaps and opportunities oriented towards the situation in the US, which are equally applicable to the situation in Chile. The first four recommendations focus on basic and translational research, public health research and strengthening clinical research. The next three recommendations concern risk assessment, d...

Revista Médica Clínica Las Condes

Journal of Oral Rehabilitation

Journal of Oral Research, 2016

Journal Oral Of Research, 2013

Resumen: Los pacientes con trastornos temporomandibulares (TTM) presentan trastornos psicológicos... more Resumen: Los pacientes con trastornos temporomandibulares (TTM) presentan trastornos psicológicos y psiquiátricos frecuentemente. Estos pacientes a menudo muestran somatización, depresión, ansiedad, reacción al estrés y catastrofismo, lo que juega un rol en la predisposición, iniciación y perpetuación de los TTM y en la respuesta al tratamiento. Esta revisión presenta opciones terapéuticas que comprometen al eje psicológico de los pacientes con TTM, las cuales buscan principalmente reducir la ansiedad y la tensión emocional presentes, modificar las distintas percepciones del dolor y cómo afrontarlo. Existen diversas posibilidades, dentro de las cuales se encuentran: educación del paciente, identificación de las situaciones que incrementan esa tensión para evitarlas, enseñanza de técnicas de relajación como biofeedback, hipnosis y yoga. En cuanto al tratamiento psicológico, la que presenta mejor resultado para los TTM, es la terapia cognitiva conductual (TCC). La intervención psicológica adecuada y eficaz puede reducir el dolor de los TTM, disminuyendo la probabilidad de que el cuadro se haga más complejo. Dentro de las alternativas de tratamiento psicológico para los TTM, un tratamiento estándar conservador (educación, instrucción de autocuidado, evitación de movimientos dolorosos, dieta blanda), incluso el más breve, puede ser suficiente a corto plazo para la mayoría de los pacientes que presentan TTM, sobretodo en los casos de cuadros agudos. La adición de una TCC, por parte de un especialista, entrega habilidades de afrontamiento que se sumarán a la eficacia, especialmente en los casos crónicos, obteniendo mejores resultados a largo plazo.

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 1999

The purpose of this article is to conduct a narrative review of current evidence regarding the un... more The purpose of this article is to conduct a narrative review of current evidence regarding the understanding, evaluation, management, and treatment of temporomandibular disorders to provide a broad perspective and updated introduction to an important and controversial subject with rapidly changing developments and limited well-designed research. Studies were identified through a search of MEDLINE for 3 topics (temporomandibular disorder, temporomandibular joint, and chronic pain) over a 10-year period (January 1988 to August 1998) and of bibliographies of identified studies and review articles. More than 5000 articles were produced. In-depth review of all of this literature was beyond the scope of the present article, which is intended to provide an overview. The amount and diversity of the literature and the limitations of covering such a broad topic being recognized, the papers selected were those that reviewed limited topics or studied focused areas. This report is not a systematic (qualitative) or meta-analysis (quantitative) review. An acknowledged limitation of this narrative review method lies in the potential for bias in selection. The referenced works do not include all papers reviewed; only pertinent literature and reviews with comprehensive references were selectively included. Advances in basic and clinical science have resulted in important changes in the understanding and management of temporomandibular disorders. Many treatments are not supported by research, and the role of dentistry is changing to a more diagnostic and management-based model from the hands-on treatment procedures of the past. The present science-based understand-ing of a biopsychosocial disorder is important in properly and responsibly dealing with patients with temporomandibular disorders.

Journal of Applied Oral Science Revista Fob, Jun 1, 2014

O bjectives: This study investigated the relationship between urease and arginine deiminase syste... more O bjectives: This study investigated the relationship between urease and arginine deiminase system (ADS) activities and dental caries through a cross-sectional study. Material and Methods: Urease and ADS activities were measured in saliva and plaque samples from 10 caries-free subjects and 13 caries-active. Urease activity was obtained from the ammonia produced by incubation of plaque and saliva samples in urea. ADS activity was obtained from the ammonia generated by the arginine-HCl and Tris-maleate buffer. Specific activity was defined as micromoles of ammonia per minute per milligram of protein. Shapiro-Wilk statistical test was used to analyze the distribution of the data, and Mann-Whitney test was used to determine the significance of the data. Results: The specific urease activity in saliva and plaque was significantly higher in individuals with low DMFT scores. ADS activity in saliva (6.050 vs 1.350, p=0.0154) and plaque (8.830 vs 1.210, p=0.025) was also higher in individuals with low DMFT scores. Conclusions: Cariesfree subjects had a higher ammonia generation activity by urease and arginine deiminase system for both saliva and plaque samples than low caries-active subjects. High levels of alkali production in oral environment were related to caries-free subjects.