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Some temporomandibular joint (TMJ) disorders start during childhood. An early treatment can avoid later surgical operation. However, it is difficult to design an early treatment because of the radiation that computed tomography scanner causes to children [1]. Also, the orthopantomography (OPG) is a planar image that causes difficulty to study the TMJ [2]. Thus, the purpose of this study is to design a computational tool able to represent the stresses at the TMJ by using an OPG image. For that purpose, a parametric finite element (FE) model of the human TMJ using active shape models (ASM) [3] obtained by OPGs was developed.

Many of the temporomandibular joint (TMJ) disorders occur during growth. An early treatment would improve the life of the patients and avoid later surgical treatment [1]. Nowadays, TMJ treatments are exclusively performed from a clinical point of view. Finite elements (FE) models are not used due to the complex geometry of the TMJ and because the properties of the soft tissues are unknown [2]. Thus, the purpose of this study is multiple: 1. To diagnose the TMJ disorder in a child patient using FE analysis. 2. To characterize the behaviour of the tissues of the TMJ using porous-fibrous material models. 3. To numerically design a non-invasive treatment. 4. To clinically perform the designed treatment.

It is well known that the periodontal ligament (PDL) plays a key role in transferring loads from the teeth to the alveolar bone, and it is becoming increasingly difficult to ignore that PDL performs greatly in tooth movements [1]. Some authors stress that the use of 3D geometry is mandatory; and plane models should never be used to simulate the tooth/bone system under load [2]. Although, more recent studies [3] proposed porohyperelastic models, the material properties of PDL are still not clarified [2][3]. The aim of this study is to validate and evaluate a finite element (FE) model based on the real geometry of a specimen extracted from a fresh human cadaver obtained by computer micro-tomography (µCT). For that purpose, the PDL behaviour was defined as a porous hyperelastic anisotropic material.

Background. Temporomandibular joint (TMJ) disorders (TMD) are defined as a subgroup of craniofacial pain problems that involve the masticatory musculature, the temporomandibular joints (TMJs), and associated structures. Pain and/or limited mouth opening are the main symptoms. The prevalence of treatment need for TMD in adults was estimated to be 15.6%. The cause of TMD remains unknown; however, TMJ overloads are a recognized factor. Aims. The main goal of this work is to assess an association between functional, dynamic and anatomical characteristics of the masticatory system in patients suffering TMD-pain condition and in healthy groups. With this in mind, our team conducted a series of studies to explain this situation, using strictly the scientific method. Method. The masticatory function of 21 completely dentate participants with chronic temporomandibular disorders (all but one with unilateral symptoms) was assessed by observing them eat almonds, inspecting the lateral horizontal movement of the jaw, with kinesiography, and by means of interview. The condylar path in the sagittal plane and the lateral anterior guidance angles with respect to the Frankfort horizontal plane in the frontal plane were measured on both sides in each individual. Results. Sixteen of 20 participants with unilateral symptoms chewed on the affected side; the concordance (Fisher’s exact test, P = .003) and the concordance-symmetry level (Kappa coefficient k = 0.689; 95% confidence interval [CI], 0.38 to 0.99; P=.002) were significant. The mean condylar path angle was steeper (53.47(10.88) degrees versus 46.16(7.25) degrees; P = .001), and the mean lateral anterior guidance angle was flatter (41.63(13.35) degrees versus 48.32(9.53) degrees P = .036) on the symptomatic side. Study power: with a sample size of 19, and assuming a two-sided test at the 0.05 level, the study had power of 0.8 to detect a value of Kappa of 0.6 or larger when testing the null hypothesis that Kappa = 0. Interpretation. The results of this study support the use of a new term based on etiology, ‘‘habitual chewing side syndrome’’, instead of the nonspecific symptom-based ‘‘temporomandibular joint disorders’’; this denomination is characterized in adults by a steeper condylar path, flatter lateral anterior guidance, and habitual chewing on the symptomatic side. Additionally, because muscular activity is responsible for TMJ-loads, muscular coactivation was assessed using surface electromyography (sEMG); although limited, sEMG could inform about some subclinical condition and about the type of muscular co-activation and their asymmetry in TMD patients, that could be of interest to elucidate the physiology of this conditionand showing moderate discriminatory capacity between TMD or healthy subjects. Lastly, this study evaluated incisal forces and muscular coactivation simultaneously. It is suggested that mean incisal forces promote equilibrated muscular coactivation; however, submaximal incisal effective forces required the activation mainly of masseter muscles; due that masseter muscles are responsibles for TMJ-loads, this study allow infer TMJ loads increases during submaximal incisal bitting; probably this task should be avoided in TMD patients. Funding. This study was financed with a grant PI11/02507 from the Institute of Health Carlos III of the Ministry of Science and Innovation of the Government of Spain. It was completed with the equipment granted by the General Directorate of Universities and Research; Department of Education and University. Xunta de Galicia. Official Journal No. 143 Galicia, July 22, 1996. And the Department of Innovation, Industry and Commerce. Xunta de Galicia, April 30, 2004. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Over the course of the dental practice, both workers and patients are exposed to a wide variety of microorganisms susceptible to cause infection. The rigorous control normally followed during disinfection and sterilization of dental equipment in dental clinics may not be followed with the orthodontic or prosthodontic equipment sent to the dental laboratory. This doctoral thesis aims to review the practices of cross contamination control in prosthetic laboratories, determine the situation in Galicia, evaluate the audiovisual resources available on the Internet for self-training, analyze the knowledge about dental impression disinfection amongst undergraduate dental students during their clinical years at the University of Santiago de Compostela and create a self-training tool adapted to the needs of the undergraduate students.

Traballo Fin de Grao en Odontoloxía. Curso 2020-2021 Objetivo: a partir de una revisión bibliográfica, determinar cuál es la altura ósea mínima para poder llevar a cabo una elevación de seno atraumática de forma predecible. Material y métodos: para la elaboración de esta revisión bibliográfica se realizó una búsqueda de artículos científicos consultando las bases de datos PubMed y Cochrane. Se utilizaron como criterios de búsqueda las palabras “osteotome”, “transcrestal”, “sinus floor”, “elevation”, “augmentation” y “residual bone height”. Se seleccionaron los estudios publicados en los últimos 5 años en inglés y castellano. Resultados: Después de la búsqueda y evaluación de la literatura según los criterios de inclusión y exclusión, entraron en la selección final 13 artículos. Los resultados de estos estudios se resumieron en una tabla y, seguidamente, se llevó a cabo una discusión con las conclusiones de los diferentes autores. Conclusiones: La altura ósea remanente del maxilar posterior no influye en la supervivencia de implantes colocados tras una elevación de seno atraumática. Esta técnica cerrada se puede realizar en alturas menores de 4 mm, siempre y cuando se asegure una estabilidad primaria adecuada. Los injertos óseos no son requisito para lograr mayor éxito en la técnica de elevación de seno atraumática. Los implantes cortos, con modificaciones de superficie y en su macrodiseño, podrían alcanzar una supervivencia similar a la de los implantes largos