Comparison of the accuracy of different types of bite recordings - an in vitro study.

OBJECTIVES: Reconstruction of a three-dimensional jaw position determined by a bite recording is an important aspect of prosthetic therapy. Different materials are used for this purpose. In the dental technical workflow, recordings are used to mount a lower jaw cast in a patient-like spatial position relative to the upper jaw cast. We evaluated the accuracy of positioning under the influence of different jaw positions and materials. MATERIALS AND METHODS: In an experimental setup, comprising an articulator, a pair of metal casts, and an optoelectronic measurement system, the spatial position of the incisal point and two condylar points were measured. To evaluate the accuracy of repeated repositioning of casts in the technical workflow, 324 measurements were taken from 108 recordings, consisting of silicone bite-stops made of addition curing silicone with 95 shore hardness, acrylic wafers, and wax recordings. The recordings were obtained in four jaw relations differing in vertical and protrusive components. RESULTS: Of the three materials/material combinations examined, silicone showed the most consistent results across all measurements, followed by the acrylic wafer system, and then wax recordings. Generally, recordings with smaller gaps between the jaws and no protrusive components showed greater deviations compared to jaw positions with greater protrusion and higher vertical dimensions. CONCLUSIONS AND CLINICAL RELEVANCE: To achieve reliable model mounting with high accuracy, recordings should include the use of a frontal jig and four small recording platelets made of silicone, especially if only a slight elevation of the vertical dimension is needed.

Maxillomandibular relationship record methods for computer-engineered complete dentures: a scoping review.

OBJECTIVES: The purpose of this scoping review was to identify different methods employed for recording the maxillomandibular relationship (MMR) for computer-aided designed and manufactured (CAD-CAM) complete dentures (CDs). MATERIALS AND METHODS: This scoping review followed the PRISMA-ScR guidelines and was developed according to Arksey and O'Malley and The Joanna Briggs Institute protocol. The methods were registered on the Open Science Framework (< osf.io/rf4xm> ). The focus question was: "What are the different techniques for recording the maxillomandibular relationship in the digital workflow used in CECDs?" Two investigators searched 3 online databases [MEDLINE (PubMed), Scopus, and Science Direct] independently. The inclusion criteria were clinical studies and reviews that assessed techniques for recording MMR using digital workflow for manufacturing of CECDs. A descriptive analysis was performed considering the study design, manufacturing system, clinical steps, and tools for the determination of MMR, and the difficulty level of procedures. RESULTS: 4779 articles were identified in the electronic search and 10 studies were included for data analysis. The review identified 4 commercially available CAD-CAM denture systems and 3 innovative methods suitable for abbreviating the number of appointments (2 to 4 visits). The trial denture is inherent to the procedure for the Baltic System and 3 innovative techniques. Three techniques (2 innovative and WholeYouNexteeth) demonstrated lower difficulty levels for performing the clinical procedures, regardless of the professional skills. CONCLUSIONS: The commercially available and innovative techniques for the recording of MMR may provide predictability of the treatment. The techniques are effective, however, rely on the learning curve and the patient's clinical condition. CLINICAL RELEVANCE: Recording of the maxillomandibular relationship is paramount for the manufacturing and functionality of complete dentures. Clinicians should be aware of the different tools and techniques described for registering the jaw relationship.

In vivo evaluation of T-Scan in quantifying occlusal contact.

BACKGROUND: The T-scan system has been used previously to analyse occlusion, but the quantitative analysis of occlusal contact by T-Scan system has yet to be reported. OBJECTIVES: To evaluate the reliability and validity of T-Scan system for quantitatively measuring occlusal contact area and occlusal contact number. METHODS: Twenty-two individuals with normal occlusion, 11 men and 11 women, were recruited for the study. Two occlusal analysis methods, including silicone transmission analysis method (STA) and T-Scan occlusion analysis method (TSO), were used to make quantitative analysis to measure occlusal contact area (OCA) and occlusal contact number (OCN). A test-retest check was performed with an interval of 2 weeks. The values of intraclass correlation coefficients (ICC) between test-retest of each method were calculated for reliability evaluation. Pearson correlations analysis, paired t-tests, regression analysis and Bland-Altman analysis were performed for validity evaluation. RESULTS: The ICC values of STA were greater than those of TSO for OCA while for OCN, ICC values of TSO were greater than STA. The higher OCA and OCN values were found in TSO compared with STA. Pearson's correlation coefficient indicated strong relations between TSO and STA (0.730-0.812) for OCA, while good relations between then (0.569-0.583) for OCN. Paired t-test showed a significant difference between the OCA and OCN values between TSO and STA. Bland-Altman analysis showed good agreement between OCA and OCN values of TSO and STA both in men and women. Regression analysis identified a linear correlation between OCA values obtained from these two methods. CONCLUSIONS: T-Scan method showed strong reliability for measuring OCA and OCN quantitatively. Strong correlations were found between OCA values from TSO and STA method, but the validity of TSO for measuring OCN needs to be promoted. CLINICAL SIGNIFICANCE: T-Scan system demonstrates good potential in quantitative analysis of occlusion, which will expand its clinical application.

Contact point marking with the OccluSense system-an in vitro study on reliability and validity.

BACKGROUND: Occlusal contacts can be stained and thereby visualised employing occlusal indicators. Qualitative and quantitative indicators are differentiated. The hybrid system OccluSense supposedly combines analogue contact marking and digital registration of contacts. The reliability and validity of its contact marking have not yet been validated. OBJECTIVES: The aim of this controlled randomised in-vitro study was to examine the reliability and validity of analogue contact staining with OccluSense compared to Arti-Fol and the reference standard Gnatho-Film. MATERIALS AND METHODS: An experimental apparatus was designed to simulate static occlusion. The occlusal contacts were stained 50 times with Gnatho-Film to determine the average number and location of contacts registered. For comparison, the contacts were pre-stained with Gnatho-Film and then registered with Arti-Fol or OccluSense 50 times each. Every staining was statistically evaluated and compared to Gnatho-Film alone, regarding the number and location of contacts. Based on the observed characteristic staining behaviour of OccluSense, a modified evaluation strategy was developed for its colour markings (OccluSense (mod.)). RESULTS: Both evaluations of OccluSense determine that the same number of contacts was registered in over 94% of all cases. Neither OccluSense nor Arti-Fol stain the exact same number of contacts as Gnatho-Film, but the modified evaluation OccluSense (mod.) did improve the results for validity. CONCLUSION: When employing the modified evaluation strategy, OccluSense staining achieves similar reliability and validity as the reference standard. Pre-colouring of occlusal contacts with Gnatho-Film and the modified evaluation strategy, might become standard for analysing occlusal contacts stained by OccluSense in the future.

Digital application of three-dimensional diagnosis and treatment with a virtual articulator.

OBJECTIVE: The purpose of this article was to introduce a method for the digital application of three-dimensional (3D) diagnosis and treatment with a virtual articulator and 3D data. CLINICAL CONSIDERATION: With the use of cone-beam computed tomography (CBCT) and intraoral and facial scans, we can create a virtual articulator and evaluate the mandibular position in maximum intercuspation and centric-related occlusion for the patient with an unstable occlusion and temporomandibular disorders (TMD). Based on this, we treated a case using a digital mandibular position indicator (MPI) and fabricated a stabilization splint using a 3D printer. This approach eliminates the traditional impression or model mounting process and the analog face bow transfer. Furthermore, the design of the stabilization splint is accomplished using software. CONCLUSIONS: The approach outlined in this article offers the potential for a digital diagnosis and treatment process by seamlessly integrating CBCT, intraoral scans, and facial scans with a high degree of accuracy. This may enhance precision in diagnosis and treatment planning, especially for patients with complicated TMD, in addition to facilitating effective communication with orthodontic patients who require thorough attention. CLINICAL SIGNIFICANCE: Utilizing a virtual articulator and digital MPI for the occlusal evaluation of patients with TMD and unstable occlusion makes it possible to diagnose and analyze the occlusal condition accurately. This approach also allows for precision and efficiency in treatment.

In Vitro Assessment of Dimensional Accuracy of Three Different Types of Interocclusal Recording Materials.

AIM: The aim of the current study was to evaluate the dimensional accuracy of three various interocclusal recording materials. MATERIALS AND METHODS: A total of 90 disc-shaped samples were prepared using polyether paste, wax, and polyvinyl siloxane material with the support of stainless steel die. For the purposes of this investigation, three frequently utilized interocclusal recording materials were chosen, and 30 samples from each material were prepared. Group I: Bite registration using polyether paste; Group II: Bite registration using wax; Group III: Bite registration using polyvinyl siloxane material. No samples were exposed to direct sunlight during storage and were kept at room temperature. Using a 10x universal measuring microscope, each sample disc was examined for the presence of horizontal and vertical lines inscripted in the die. For each of the samples, readings were taken at different time periods of 24, 48, and 72 hours. RESULTS: After 24 hours, the less dimensional changes were found in polyether paste group (0.11 ± 0.07) followed by polyvinyl siloxane material group (0.19 ± 0.04) and wax group (0.25 ± 0.12). After 48 hours, the less dimensional changes were found in polyether paste group (0.34 ± 0.02) followed by polyvinyl siloxane material group (0.42 ± 0.01) and wax group (0.94 ± 0.12). After 72 hours, the least dimensional changes were found in polyether paste group (0.46 ± 0.14) followed by polyvinyl siloxane material group (0.92 ± 0.03) and wax group (1.14 ± 0.09). CONCLUSION: The present study concluded that both the material and time factors had an impact on dimensional stability. The most dimensionally stable group was the polyether paste group, which was followed by the polyvinyl siloxane and wax material groups. CLINICAL SIGNIFICANCE: Interocclusal recording material records the occlusal connection between real or artificial teeth for occlusal rehabilitation planning and for creating removable and fixed dentures. The creation of a clinically acceptable prosthesis is dependent upon the accuracy of the patient's diagnostic or working casts and the interocclusal record. How to cite this article: Sonkesriya S, Subramanian D, Saha P, et al. In Vitro Assessment of Dimensional Accuracy of Three Different Types of Interocclusal Recording Materials. J Contemp Dent Pract 2023;24(12):936-939.

Evaluation of the accuracy of a fully digital method of measuring sagittal condylar inclination.

OBJECTIVES: This clinical study aimed to evaluate the accuracy of a fully digital technique for measuring sagittal condylar inclination (SCI), as well as validating whether differences existed between the left and right SCI values of the same participant, to provide a reference for clinical practice. METHODS: Ten participants with good occlusal relationship and normal temporomandibular joint were recruited. Three methods were used to measure the SCI values of the participants, namely, A (mechanical facebow transferring and mechanical articulator-based measuring method with physical protrusive interocclusal registration), B (face scan-based virtual facebow and virtual articulator-based measuring method with digital protrusive interocclusal registration), and C (jaw motion tracking system-based measuring method). With the group subjected to methods A and C as the control, the SCI values obtained by the three methods were statistically analyzed. The left and right SCI values of the same participant were also compared. RESULTS: The left and right SCI values measured by method A were 41.70°±7.09° and 42.80°±8.62°, those by method B were 35.09°±12.49° and 37.63°±12.10°, and those by method C were 39.43°±8.72° and 38.45°±6.91°. No significant difference existed among the SCI values measured by the three methods (P>0.05). Meanwhile, no statistical difference existed between the SCI values on the left and right sides of the same participant (P>0.05). CONCLUSIONS: The accuracy of the virtual facebow and digital protrusive occlusal registration based SCI measuring method was the same as that of mechanical facebow based and jaw motion tracking system-based methods. The SCI values on the left and right sides of the same participant were similar. Clinically, an appropriate SCI measurement and setting strategy can be selected based on the actual situations.

Precise jaw relation recorder: An innovative device for prosthodontic rehabilitation.

BACKGROUND: The orchestration of jaw relations in edentulous scenarios poses a significant challenge, demanding acumen, and expertise from the clinician. A myriad of devices, substances, and methodologies are employed to gauge the transverse, vertical, and horizontal spectrums of jaw relations. Traditionally, a synthesis of assorted devices and techniques has been requisitioned to chronicle the spatial dynamics between the maxilla and mandible. Yet, the absence of a solitary apparatus capable of concurrently documenting the triad of jaw relations has been a notable lacuna in prosthodontic rehabilitation. PURPOSE: This discourse expounds on an innovative contrivance, termed the Precise Jaw Relation Recorder. This pioneering instrument is adept at capturing the tripartite jaw relation processes: the occlusal plane's alignment in parallelism to the ala-tragus line, the vertical dimension at repose, and the occlusion as well as the centric relation. The device's strategic utility lies in its ability to facilitate the creation of prostheses that are not only functionally superior but also aesthetically more pleasing. CONCLUSION: Its implementation is a stride toward refining the accuracy of prosthodontic outcomes, thereby elevating the standard of patient care in dental practice.

Discrepancia anteroposterior en registro de relación céntrica con apoyo central intraoral en cubetas rodetes acrílicas (BOPAYACU) e inducción manual en adultos mayores desdentados totales / Anteroposterior discrepancy in centric relation record with intraoral central support in acylic impaction cups (BOPAYACU) and manual induction in edentulous older adults

Objetivo: Comparar la discrepancia anteroposterior medida a nivel de la platina incisiva de 2 métodos de registro intermaxilar en la misma sesión que la im-presión definitiva en adultos mayores desdentados totales. Materiales y métodos. Se incluyeron en el es-tudio 20 pacientes (n=20) con edad promedio de 70 años. En cada uno de ellos se obtuvieron registros intermaxilares con cubetas rodete de acrílico: uno con inducción manual (IM) y otro autoinducido con el sistema de cubeta rodete de acrílico y apoyo central único utilizando una superficie palatina de registro curva (BYC). Los modelos fueron montados en un ar-ticulador Whip Mix modelo 2240 al que se le adicio-nó un dispositivo de papel milimetrado, Orthodent, a nivel de la platina incisiva, para registrar las dife-rencias existentes entre las posiciones obtenidas. El análisis estadístico se llevó a cabo mediante el cálcu-lo de intervalos de confianza (95%) para las diferen-cias medias y prueba de t de student para datos apa-reados (nivel de significancia: α<0,05). Resultados. En el plano mesiodistal a nivel de la platina incisiva se encontró diferencia estadísticamente significativa entre las dos variables de registro (p<0,001). A este nivel el BYC proporcionó registros más retrusivos que IM. Media aritmética (desviaciones estándar) en milímetros: 3,82 (2,1). Conclusión. El sistema de re-gistro con cubetas rodete acrílicas y BYC incorpora-do a las mismas proporciona un registro intermaxi-lar más retrusivo que IM en adultos mayores des-dentados totales cuando se realizan dichos registros en la misma sesión que la impresión definitiva (AU)

Objective: To compare the anteroposterior discre-pancy measured at the level of the incisal plate of 2 methods of intermaxillary registration in the same session as the definitive impression in fully edentu-lous older adults. Materials and methods. Twenty pa-tients (n=20) with an average age of 70 years were included in the study. On each of them, intermaxillary recordings were obtained with acrylic rims trays: one with manual induction (MI) and the other with a self-induced system and single central support using a curved recording palatal surface (BYC). The models were mounted in a Whip Mix model 2240 articula-tor to which an Orthodent graph paper device was added, at the level of the incisal plate, to record the di-fferences between the positions obtained. Statistical analysis was carried out by calculating confidence intervals (95%) for mean differences and T-student for paired data (significance level: α<0.05). Results. On the mesiodistal plane at the level of the incisal plate, a statistically significant difference was found between the two recording variables (p<0.001). At this level the BYC provided more retrusive recordings than MI. Arithmetic mean (standard deviations) in mi-llimeters: 3.82 (2.1). Conclusions. The registration system with acrylic rim trays and BYC incorporated into them provides a more retrusive intermaxillary registration than MI in fully edentulous older adults when such registrations are made in the same ses-sion as the final impression.(AU)

Application of 3D Electromagnetic Articulography in Dentistry: Mastication and Deglutition Analysis. Protocol Report / Aplicación de la Articulografía Electromagnética 3D en Odontología: Análisis de la Masticación y Deglución. Reporte de Protocolo

ABSTRACT: The Stomatognathic System (SS) is an integrated and coordinated morphofunctional unit, consisting of skeletal, muscular, angiological, nervous, glandular and dental structures that work in harmony to perform different functions such as chewing, swallowing, speaking, breathing, tasting and esthetics. The study of SS physiology is crucial to achieving a correct maintenance of its normal function or restoration. Thus, we developed a protocol to record mandibular movement, chewing and swallowing (saliva and water) by using the 3D-electromagnetic articulograph AG501 at the Oral Physiology Laboratory of the Research Centre for Dental Sciences (CICO). This tool has been used for decades in speech and phonetic research and it is able to record, present and evaluate articulated structure movement data in real time. The articulograph provides an ordered data matrix (values ??for the x, y, z axes, among others) for the recorded movement, which is stored in binary files that can be processed by different software. One of these is MATLAB®, allowing us to perform a quick, clear and understandable analysis. The existence of a standardized methodology for recording allows an accurate description of the stages to perform different types of measurements according to the researcher's objective. This has opened the way for a new type of oral physiology analysis based on study reproducibility, which is considered one of the bases of scientific methodology.

RESUMEN: El Sistema Estomatognático es una unidad morfo-funcional integrada y coordinada, constituida por estructuras esqueléticas, musculares, angiológicas, nerviosas, glandulares y dentales que actúan en armonía para realizar diferentes funciones como la masticación, deglución, fonoarticulación, respiración, degustación y estética. Es importante el estudio de la fisiología del SE para lograr un correcto mantenimiento de su función normal, o para la restauración de este. Es así como en el Laboratorio de Fisiología Oral del Centro de Investigación en Ciencias Odontológicas (CICO) hemos desarrollado un protocolo para el registro del movimiento mandibular, masticación y deglución (saliva y agua), utilizando el articulógrafo electromagnético 3D AG501, el cual ha sido utilizado desde hace décadas en la investigación del habla y la fonética y que es capaz de grabar, presentar y evaluar en tiempo real datos del movimiento de estructuras articuladas. El articulógrafo provee de una matriz de datos ordenados (valores para los ejes x, y, z, entre otros) para el movimiento registrado, el cual se almacena en archivos binarios que pueden procesarse a través de diferentes softwares. Uno de ellos es MATLAB®, el cual nos permite realizar un análisis de forma rápida, clara y comprensible. La existencia de una estandarización metodológica de registro, permite describir de forma exacta las etapas para llevar a cabo distintos tipos de mediciones según el objetivo del investigador. De esta forma se abre la puerta a una nueva forma de análisis en la fisiología oral que se sustenta en la reproducibilidad de la investigación que es considerada una de las bases de la metodología científica.

Influence of Class II Elastics on Centric Relation and Centric Occlusion Discrepancy after Orthodontic Treatment / Influencia de los Elásticos de Clase II sobre la Discrepancia de Relación Céntrica para la Oclusión Céntrica Después del Tratamiento Ortodóncico

ABSTRACT: The objective of this study was to verify the influence of the use of Class II intermaxillary elastics on centric relation (CR) to centric occlusion (CO) occlusal discrepancy. A total of 30 patients had been at the contention stage for at least three months were divided in two groups: G1 - 15 had been submitted to intramaxillary orthodontic mechanics only, and G2 - 15 had used Class II intermaxillary elastics. Distances of horizontal and vertical overlap and the distance or coincidence of the mandibular dental midline in relation to the maxillary midline were measured in CR and CO positions. Intergroup comparisons were performed using the Mann-Whitney test. No statistically significant differences (P>0.05) were found between G1 and G2. Both in the horizontal and vertical directions, these discrepancies were smaller than or equal to 1mm in 96.66 % of the patients. In the transverse plane, there was no discrepancy in 63.33 % of the patients, and in 33.33 % these discrepancies were equal to 0.5 mm. The use of Class II elastic didn't be capable of increasing the occlusal discrepancies between CR and CO.

RESUMEN: El objetivo de este estudio fue verificar la influencia del uso de los elásticos intermaxilares Clase II en la discrepancia oclusal entre la relación céntrica (RC) y la oclusión céntrica (OC). Un total de 30 pacientes que permanecieron en la fase de contención durante al menos tres meses se dividieron en dos grupos: G1 - 15 fueron sometidos solamente a la mecánica ortodóncica intramaxilar, y G2 - 15 habían utilizado elásticos de clase II intermaxilar. Se midieron las distancias de traslapo horizontal y vertical y la distancia o coincidencia de la línea mediana dentaria mandibular con respecto a la línea mediana maxilar en las posiciones RC y OC. Las comparaciones entre grupos se realizaron mediante la prueba de Mann-Whitney. No se encontraron diferencias estadísticamente significativas (P> 0.05) entre G1 y G2. Tanto en las direcciones horizontal como vertical, estas discrepancias fueron menores o iguales a 1 mm en el 96,66 % de los pacientes. En el plano transversal, no hubo discrepancia en el 63,33 % de los pacientes, y en un 33,33 % estas discrepancias fueron iguales a 0,5 mm. El uso de la clase II elástica no logró aumentar las discrepancias entre RC y OC.

Diagnóstico cefalométrico de la relación sagital intermaxilar, ángulo ANB y pruebas alternativas: artículo de revisión / Cephalometric diagnosis of intermaxillary sagittal relationship, ANB angle and alternative tests: a review article

La manifestación clínica de la relación sagital entre los maxilares superior e inferior ha sido utilizada de forma fiable y válida, hasta la actualidad. El objetivo de este trabajo ha sido realizar una revisión histórica y análisis del estado arte del Ángulo ANB como prueba diagnóstica gold estándar de la relación sagital intermaxilar necesaria para decidir el tipo de tratamiento ortodóncico u ortopédico a aplicar, así como un estudio de los diferentes factores que pueden afectar la validez de este test de diagnóstico, además de hacer una revisión de pruebas diagnósticas alternativas propuestas por diferentes autores, establecer su funcionalidad en la toma de decisiones clínicas terapéuticas. Se realiza una revisión de las diferentes metodologías estadísticas como estudios de correlación y uso del análisis deCaracterística Operativa Relativa (ROC), que observa la sensibilidad y la especificidad de la prueba y es un indicador de su habilidad diagnóstica. Esta revisión sistemática se la ha realizado en base a información bibliográfica (1952-2015) a través de Biblioteca virtual, en Postgrado de Ortodoncia de la Facultad de Odontología de la Universidad de Buenos Aires.

The clinical manifestation of anteroposterior relationship between the upper and lower jaws has been used in a reliable and valid untiltoday. The aim of this study was to conduct a historical review and state of the art analysis of ANB angle as a diagnostic gold standardsagittal intermaxillary relationship needed to decide the type of orthodontic or orthopedic treatment to apply, and a study of the differentfactors that can affect the validity of the diagnostic test, in addition to a review of alternative diagnostic tests proposed by differentauthors, establish their functionality in making therapeutic clinical decisions. Reviews of the different statistical methodologies ascorrelation studies and analyzes of Relative Operating Characteristic (ROC) were performed, noting the sensitivity and specificity of thetest, being an indicator of its diagnostic utility. This systematic review has made based on bibliographic information (1952-2015) through Virtual Library in Orthodontics Graduate School of Dentistry at the University of Buenos Aires.

Comparación de la posición condilar entre dos técnicas de registro de relación céntrica mediante tomografía espiral / Condylar position comparison between two centric relation recording methods, by means of a spiral tomography technique

Objetivo: El objetivo de este estudio fue comparar la variación de la posición del cóndilo mandibular entre la técnica de registro de relación céntrica auto-inducida de tipo activa y otra de manipulación mandibular de tipo chin-point. Método: En una muestra por conveniencia de 9 sujetos (4 hombres y 5 mujeres), se estudiaron un total de 18 articulaciones témporomandibulares determinando la variación de la posición condilar con el uso de imágenes obtenidas mediante tomografía espiral, utilizando para ambas técnicas un deprogramador anterior de Neff para estandarizar el grosor del material de registro. Resultados: Se observó que con la técnica chin-point, el cóndilo adopta una posición más posterior (55.6 por ciento) y superior (72.2 por ciento) respecto a la auto-inducida de tipo activa, con diferencias estadísticamente significativas (p<0.001, t-test). En promedio se observó que la técnica chin-point produjo una magnitud de desplazamiento de 1.5mm en dirección cefálica y 1.1mm hacia posterior, tomando como referencia la posición registrada con la técnica auto-inducida de tipo activa. Conclusiones: La técnica chin-point produce una posición condilar más posterior y superior que la técnica auto-inducida de tipo activa.

Objective: The aim of this study was to compare the mandibular condylar position between two centric relation recording methods: Active self-induced type and chin-point manipulation. Method: In a convenient sample of 9 subjects (5 females and 4 males), the condylar position variation was determined in the 18 temporomandibular joints by means of a spiral tomography radiographic technique. To standardize the thickness of the registration material, a Neff anterior deprogramming appliance was used. Results: It was observed that with the chin-point technique, the condyle adopted a significantly more superior (72.2 percent) and posterior (55.6 percent) position compared to the active self-induced technique (p<0.001, t-test). Regarding magnitudes, chin-point produced an average of 1.5mm cephalic and 1.1mm posterior displacements, using the position obtained with the active self-induced technique as a reference. Conclusions: Chin-point technique generates a more superior and posterior condylar position that the one determined by the active self-induced.

Thickness and marking quality of different occlusal contact registration strips

Objectives Evaluate the thickness and the marking quality of different occlusal contact registration strips (OCRS) and a possible correlation between them. Material and Methods The following OCRS were selected: Accufilm II, BK20, BK21, BK22, BK23, BK28, and BK31. The thickness was measured in three points of the OCRS with an electronic measuring device (TESA), and the mean was calculated. To produce the marks on the strips, composite resin specimens were adapted to a universal testing machine (Versat 2000) with 40 kgf load cell at a speed of 1.0 mm/min. The mark images were photographed with a stereoscopic microscope (Stemi SV11) and processed and analyzed by the 550-Leica Qwin® analyzer. Results Values (μm) found in the 1st and 2nd thickness measurements were: Accufilm II - 16.4 and 14.2; BK20 - 10.0 and 8.1; BK21 - 9.5 and 8.0; BK22 - 9.7 and 8.7; BK23 - 9.8 and 7.9; BK28 - 12.8 and 10.0; and BK31 - 8.4 and 8.0, respectively. The mean (mm2) values found in the mark areas were: Accufilm II - 0.078; BK20 - 0.035; BK21 - 0.045; BK22 - 0.012; BK23 - 0.022; BK28 - 0.024; and BK31 - 0.024. The results were submitted to the Kruskal-Wallis (p<0.05) and Pearson’s correlation tests. Conclusions Only in the 2nd measurement, the OCRS thickness observed was similar to the value indicated by the manufacturers; the Accufilm II and the BK28 strips showed the better marks; and no correlation was found between the thickness and the marking area. .

Métodos de registro de la relación céntrica: ¿Son una necesidad en el diagnóstico y tratamiento de ortodoncia? / Recording methods for centric relation: are they a need in orthodontics

Esta revisión bibliográfica se refiere a los métodos de registro de la Relación Céntrica (RC) con un recorrido de la literatura desde 1921a la actualidad en busca de aclarar su definición. Esta controvertida posición cráneo mandibular lleva a una evolución en las técnicasde su registro.El objetivo es describir los métodos de registro, clasificarlos, aportar conocimiento y demostrar su necesidad en el momento del diagnósticoy el plan de tratamiento de acuerdo a las definiciones más aceptadas de RC.

This literature review analyzes the methods of recording Centric Relation (CR) with a previous revision throughout the years seekingto clarify its definition.This controversial craniomandibular position has gone through many changes in it’s registration techniques. A description of the techniquesis made until arriving to the most recent ones according the current accepted definition. The aim is to describe the methods ofrecording, classify them and provide information in order to choose a method in orthodontics diagnosis and treatment, and demostrateits need according to the most accepted definition of Centric Relation.

Estudio preliminar de patrones de mordedura según forma del cráneo, mediante el análisis morfológico y morfométrico de semiarcadas dentarias de perro doméstico (Canis familiaris) con fines de identificación / Preliminary study of bite patterns according to skull shape, by morphological and morphometric analysis of dental semi arcs of domestic dog (Canis familiaris) for identification

La Odontología forense es una rama de las Ciencias Forenses que se utiliza para establecer la identidad de una víctima o victimario mediante el estudio de las huellas de mordeduras, estimación de edad cronológica, entre otros. Dada la inexistencia de este tipo de estudios en Chile y la magnitud que alcanza el problema de mordidas de perros en Chile, se compararon los patrones de huellas de mordedura según forma del cráneo, mediante el análisis morfológico y morfométrico de semiarcadas dentarias de perro doméstico (Canis familiaris) con fines médico legal. Para ello se obtuvieron modelos dentarios en yeso e impresiones de huellas de mordedura en cera de tres razas puras: Bóxer, Dálmata y Ovejero Alemán. Las mediciones contemplaron la distancia máxima externa entre caninos superiores e inferiores y la distancia máxima externa entre incisivos superiores e inferiores. Los principales resultados muestran que sólo la distancia máxima entre caninos superiores permitiría identificar la raza en forma estadísticamente significativa (p0,05) en los modelos de yeso. En el estudio ciego y desde el punto de vista morfométrico se identificaron especialmente los Dálmata con un alto grado de sensibilidad y especificidad. Un poco menor y en forma variable se observó en Bóxer y Ovejero Alemán. El estudio morfológico permitió identificar e individualizar al 100 por ciento de los perros. Por tanto los métodos morfométricos y morfológicos son herramientas complementarias para identificar e individualizar a un posible perro agresor.

Forensic dentistry is a branch of Forensic Sciences used to establish the identity of a crime victim or perpetrator, among these studies are bite marks and dental chronological age studies. In the absence of such studies in Chile and considering the widespread problem of dog bites in Chile, bite patterns were compared according to skull shape, by morphological and morphometric analysis of dental semi arcs of domestic dog (Canis Familiaris) for medico legal purposes. Plaster dental models and impressions of bite marks were obtained of three pure breeds: Boxer, Dalmatian and German shepherd. Measures included he maximum external distance between upper and lower canine, and maximum external distance between upper and lower incisors. Main results show that only the maximum distance between upper canine would allow statistically significant race identification, (p0.05) in cast models. In a blind study and from a morphometric point of view, Dalmatians were identified with a high rate of sensitivity and specificity. A somewhat lesser and variable form was observed in Boxer and German Shepherd. The morphological study allowed identification and individualization of 100 percent of dogs. Therefore, both morphological and morphometric methods are useful and complementary tools to identify and individualize a potentially aggressive dog.

Avaliação de marcas de mordidas em alimentos produzidas por próteses dentárias / Evaluation of bite marks made by dental prostheses in foods

O estudo de marcas de mordidas em alimentos é uma importante vertente da Odontologia Legal, pois através do seu emprego é possível identificar ou excluir suspeitos de atos criminosos. O objetivo deste trabalho foi avaliar a viabilidade de identificação através de marcas de mordidas em alimentos, realizadas por próteses dentárias. A amostra foi composta por 10 (dez) pares de próteses, confeccionadas em um laboratório e montadas em um articulador tipo charneira. Após numeração das mesmas e dos alimentos, foi realizado um sorteio. Em seguida, procedeu-se a realização das mordidas nos alimentos (quatro chocolates, quatro queijos e duas bananas), sem o conhecimento dos pesquisadores. Modelos de gesso das próteses e dos alimentos mordidos foram confeccionados, utilizando alginato e gesso pedra. Em seguida, empregou-se a técnica da análise métrica. Nesta etapa realizou-se a mensuração do diâmetro mésio-distal de cada dente nos modelos dos alimentos e das próteses, utilizando um paquímetro digital. Posteriormente, foi feita comparação direta do alimento mordido com os modelos das próteses. Dos dez alimentos mordidos foi possível identificar com precisão a prótese responsável pela impressão dentária em 7 deles. Entretanto, no queijo 01 e 02 e no chocolate 03 não foi possível identificar o autor, mas excluir 8, 5 e 8 suspeitos, respectivamente. De acordo com os resultados obtidos pode-se comprovar que é possível a identificação de marcas de mordidas produzidas por próteses, contribuindo assim com as perícias realizadas na área de Odontologia Legal.

Comparative study of intermaxillary relationships of manual and swallowing methods

This study compared the mandibular displacement from three methods of centric relation record using an anterior jig associated with (A) chin point guidance, (B) swallowing (control group) and (C) bimanual manipulation. Ten patients aged 25-39 years were selected if they met the following inclusion criteria: complete dentition (up to the second molars), Angle class I and absence of signs and symptoms of temporomandibular disorders and diagnostic casts showing stability in the maximum intercuspation (MI) position. Impressions of maxillary and mandibular arches were made with an irreversible hydrocolloid impression material. Master casts of each patient were obtained, mounted on a microscope table in MI as a reference position and 5 records of each method were made per patient. The mandibular casts were then repositioned with records interposed and new measurements were obtained. The difference between the two readings allowed measuring the displacement of the mandible in the anteroposterior and lateral axes. Data were analyzed statistically by ANOVA and Tukey's test at 5 percent significance level. There was no statistically significant differences (p>0.05) among the three methods for measuring lateral displacement (A=0.38 ± 0.26, B=0.32 ± 0.25 and C=0.32 ± 0.23). For the anteroposterior displacement (A=2.76 ± 1.43, B=2.46 ± 1.48 and C=2.97 ± 1.51), the swallowing method (B) differed significantly from the others (p<0.05), but no significant difference (p>0.05) was found between chin point guidance (A) and bimanual manipulation (C). In conclusion, the swallowing method produced smaller mandibular posterior displacement than the other methods.

Este estudo comparou o deslocamento mandibular a partir de 3 métodos de registro da relação cêntrica usando um jig anterior associado com: (A) guia da ponta do mento; (B) deglutição grupo controle (C) manipulação bimanual. As moldagens dos arcos maxilares e mandibulares foram feitas com hidrocolóide irreversível. Os modelos de estudo de cada paciente foram obtidos e montados em máxima intercuspidação como uma posição de referência no microscópio. Foram obtidos 5 registros de cada método em 10 pacientes. Os modelos mandibulares foram reposicionados com os registros interpostos e novas medidas foram obtidas. A diferença entre as duas leituras permitiu a medida do deslocamento mandibular nos eixos ântero-posterior e laterais. ANOVA não demonstrou diferença estatisticamente significativa entre os 3 métodos em relação ao registro do deslocamento lateral (A = 0,38 ± 0,26, B = 0,32 ± 0,25 e C = 0,32 ± 0,23). Quanto ao deslocamento anteroposterior, ANOVA e o teste de Tukey (a=0,05) indicaram diferença estatisticamente significante entre os três métodos (A=2,76 ± 1,43, B=2,46 ± 1,48 e C=2,97 ± 1,51). Não houve diferença estatisticamente significante entre A e C. A deglutição propiciou menor deslocamento mandibular posterior que os outros métodos.

Avaliação das dimensões programáveis dos articuladores semi-ajustáveis / Assessment of the programmable dimensions of the semi-adjustable articulador

O articulador semi-ajustável tem o propósito de reproduzir as relações maxilomandibulares estáticas e, parcialmente, as dinâmicas. No entanto, parte destas características depende da qualidade da fabricação dos aparelhos. O objetivo foi aferir os componentes responáveis pela determinação do ângulo de Bennett (AB), da eminência articular (EA) e da distância intercondilar (DI) do articulador semi-ajustável (ASA) Dentflex...

Registro de mordida neuromuscular para ortopedia con Tens / Neuromuscular bite recording for orthopedics with Tens

El propósito de este artículo es difundir la odontología neuromuscular, su fundamento, filosofía y en esta oportunidad, aplicarla a la toma del registro de mordida para la confección de aparatología de ortopedia funcional.