Alterações dimensionais em marcas de mordidas humanas simuladas em alimentos: estudo in vitro / Dimensional changes in simulated human bite marks on food: in vitro study

Objetivo: avaliar alterações dimensionais em marcas de mordidas simuladas em um tipo de queijo e de goiabada com o decorrer do tempo. Materiais e Métodos: mordidas foram simuladas em 20 amostras-padrão formato retangular nas medidas 30 x 60 mm e espessura de 20 mm de queijo tipo muçarela (n=10) e goiabada (n=10) com a utilização de um manequim odontológico montado em oclusão normal e acoplado à máquina universal de ensaios mecânicos. Amostras foram mantidas em superfície de vidro em ambiente com temperatura e umidade controladas seguida da aferição das distâncias intercaninas das marcas a cada hora com auxílio de paquímetro digital, durante 120 horas de experimentação. A temperatura e umidade mantiveram-se constantes durante todo período. As medidas obtidas foram estatisticamente analisadas por meio dos testes de Friedman, de Wilcoxon, coeficiente de correlação de Spearman e a partir da análise de regressão linear simples. O nível de significância adotado foi de 5%. Resultados: os alimentos testados mantiveram o padrão das medidas lineares nas primeiras quatro horas (p>0,05). Após esse período, ocorreu uma deformação progressiva, levando ao aumento significativo das medidas (p<0,05). Conclusão: a marca de mordida em queijo tipo muçarela e goiabada apresentou-se dimensionalmente estável nas primeiras quatro horas, pós mordida. Após esse período, as marcas já não apresentaram características favoráveis para serem utilizadas como registro para fins de comparação.

Objective: to evaluate dimensional changes in simulated bite marks in a type of cheese and guava paste over time. Materials and Methods: Bites were simulated on 20 standard rectangular samples. in the measures 30 x 60 mm and thickness of 20 mm of mozzarella cheese (n=10) and guava paste (n=10) using a dental manikin mounted on normal occlusion and coupled to the universal mechanical testing machine. The samples were kept on a glass surface in an environment with controlled temperature and humidity , followed by the measurement of intercanine distances of the marks, every hour, with the aid of a caliper digital, during 120 hours of experimentation. The temperature and humidity remained constant throughout the period. The measurements obtained were statistically analyzed using the Friedman, Wilcoxon, Spearman's correlation coefficient and from the linear regression analysis simple (IBM SPSS. 21.0, 2012, Armonk, NY: IBM Corp.). The level of significance adopted was 5%. Results: the foods tested maintained the pattern of linear measurements in the first four hours (p>0.05). After this period, a progressive deformation occurred, leading to the significant increase in measurements (p<0.05). Conclusion: the bite mark in mozzarella cheese and guava paste it was dimensionally stable in the first four hours, post-bite. After this period, brands no longer have favorable characteristics to be used as a record for comparison purposes.

A comparative study based on the mandibular movement track and the movement parameters of the virtual articulator in simulating occlusal adjustment / 华西口腔医学杂志

OBJECTIVES@#This study aimed to compare the effects of virtual adjustment on occlusal interferences in mandibular posterior single crown and three-unit bridge restorations by using the mandibular movement track and the movement parameters of a virtual articulator.@*METHODS@#Twenty-two participants were recruited. Digital casts of the maxillary and mandibular arches were obtained using an intraoral scanner, and the jaw registration system was used to record the data of the mandibular movement track and the movement parameters of the articulator. Four kinds of restorations with 0.3 mm occlusal interferences were designed with dental design software. In particular, single crowns were designed for teeth 44 and 46, whereas three-unit bridges were designed for teeth 44-46 and 45-47, and the corresponding natural teeth were virtually extracted. Virtual adjustment of the restorations was performed using two dynamic occlusal recordings, namely, the mandibular movement track and the movement parameters of the virtual articulator. A reverse-engineering software was used to measure the root-mean-square of the three-dimensional deviation of the occlusal surfaces between natural teeth and the adjusted restorations. The differences between the two methods of virtual-occlusion adjustment were compared and analyzed.@*RESULTS@#For the same group of restorations, the three-dimensional deviation of the mandibular movement track group were lower than those of the virtual articulator group, and the differences were statistically significant (P<0.05). For the four groups of restorations adjusted by the same method, the three-dimensional deviation of the 46-tooth single crown was the largest and the smallest three-dimensional deviation was that of the 44-tooth single crown. Statistical differences existed between the 44-tooth single crown and the other groups (P<0.05).@*CONCLUSIONS@#For the occlusal design of posterior single crown and three-unit bridge, the mandibular movement track could be a more effective approach to virtual occlusal adjustment than the movement parameters of the virtual articulator.

A clinical application study of digital manufacturing simple intraoral Gothic arch-tracing device in determining the centric relation of complete dentures / 北京大学学报(医学版)

OBJECTIVE@#To verify the consistency between the digital manufacturing simple intraoral Gothic arch-tracing device and the traditional intraoral Gothic arch-tracing device in determining the centric relation of complete dentures restoration.@*METHODS@#Ten outpatients with edentulous jaws were selec-ted, and the centric relation of the patients was determined by digital manufacturing of simple intraoral Gothic arch-tracing device (T1) and traditional intraoral Gothic arch-tracing device (T2); the difference of clinical operation time between the two methods was recorded; the upper and lower edentulous jaw plaster models were scanned with two kinds of centric relation, the Standard Triangle Language (STL) files imported into Geomagic studio software to apply the best fitting of multiple points of the both upper jaw models, the fitted STL files imported into the 3 shape viewer software, and the maximum position deviations of the vertical, labial (buccal) and lingual directions of the mandibular midline area and molar areas in T1 and T2 groups measured. During the clinical complete dentures try-in, we observed whether there was midline deviation in the mouth of T1 group and T2 group, and whether the occlusion of posterior teeth was stable or not.@*RESULTS@#The mean time spent on determining the centric relation of T1 and T2 groups was (41.90±2.64) min, (57.50±2.37) min respectively. Paired t test was conducted in the two groups, P < 0.01 with significant statistical difference; The mean maximum position deviation between T1 group and T2 group of the midline mandibular region in labial lingual direction was (0.32±0.14) mm, that was (0.40±0.23) mm in vertical direction; the mean maximum position deviation of molar area in buccal lingual direction was (0.35±0.23) mm and that was (0.33±0.20) mm in vertical direction. In the vertical and horizontal directions, the maximum position deviation of mandibles between group T1 and group T2 was controlled within 0.5 mm. In the process of clinical complete dentures try-in, there was no deviation from the center line of dentures. There was not warping, swinging and other poor stability phenomena in T1 and T2 groups.@*CONCLUSION@#The digital manufacturing of simple intraoral Gothic arch-tracing device can be used to determine the centric relation of complete dentures, which can not only save time of clinical operation, but also ensure the accuracy of the centric relation.

Three dimensional analysis and comparison of human anterior teeth and experimentally created bitemark depressions

A system was proposed to scan dental models to record three-dimensional features seen in the anterior teeth to create a database of dental profiles. Dental casts were randomly selected to create indentations in cowhide leather. Reid Bite Reader was used to measure the bite forces generated by Reynolds Controlled Bite Force Generator to make the teeth impressions. Using the Immersion MicroScribe® 3D, information from the 53 bitemark depressions and 62 sets of dental casts were transferred to an Excel Spreadsheet. Software was developed to perform the 3D comparison using metric and pattern analysis. Statistical analysis showed 100% success when comparing both arches together of the dental casts with the bitemarks or different dental casts.

Method and accuracy of determining the jaw position of repositioning splint with the aid of digital technique / 北京大学学报(医学版)

OBJECTIVE@#To establish the workflow of determining the jaw position of repositioning splint with the aid of digital technique, and to evaluate the accuracy of this workflow and compare the accuracy of raising different vertical dimensions in vitro.@*METHODS@#A volunteer was recruited. The data of full-arch scans, cone beam computed tomography (CBCT) image and ultrasonic jaw motion tracking of the volunteer were acquired. The full-arch scans were merged with the CBCT image, which were then matched to the jaw motion tracking reference system. The jaw position of repositioning splint was determined when the anterior teeth opening was 3 mm and the condyle was in centric relation of the fossa in the sagittal plane. A digital repositioning splint was designed in the software based on virtual articulator and fabricated with additive manufacturing technique. After the splint was tried in, another CBCT image was taken and a qualitative analysis was conducted to compare the position of condyle between these two CBCT images. In the in vitro study, standard dental plaster casts with resin ball markers attached to the base were mounted onto a fully adjustable articulator in the intercuspal position. The dental casts were scanned by an extraoral scanner to establish digital models. The ultrasonic jaw motion tracking device was used to obtain simulated jaw movements on the articulator, which was repeated for three times. The digital models and data of jaw movements were merged in one coordination with the aid of bite forks. The jaw position of repositioning splint was determined by adjusting data of jaw movements, each of which was used to determine three vertical jaw positions 4 mm, 5 mm, and 6 mm with the horizontal jaw position of protrusion 2 mm. The virtual articulators with differently adjusted jaw movements were applied in designing repositioning splints, and the final repositioning splints and virtual jaw relationships were exported in STL format. Then the repositioning splints were fabricated with additive manufacturing technique and tried in plaster casts on the mechanical articulator, which were scanned and the jaw relationships on the mechanical articulator were exported later. The virtual jaw relationships and scanned jaw relationships were registered according to lower models and displacement of upper models was calculated. Ball markers were fit to acquire the coordinates of centers and absolute difference values of centers along three coordinating axes X, Y, and Z were calculated. One-way analysis of variance was conducted using SPSS 18.0 software to compare deviations of the three different vertical jaw relationships in two-side test and the significance level was 0.05.@*RESULTS@#With the aid of multi-source data fusion and individualized jaw motion, the clinical workflow of determining jaw position of repositioning splint was preliminarily established. The designed jaw position was realized on the right and the condyle was more inferior than the designed position on the left. Both displacement of the upper models and absolute difference values of centers showed no significant differences (P>0.05) in different vertical jaw dimensions. The displacement of the upper models was (0.25±0.04) mm. The absolute difference values of centers along the three coordinating axes X, Y, and Z were respectively (0.08±0.01) mm, (0.30±0.02) mm, and (0.21±0.04) mm.@*CONCLUSION@#A novel method of determining the jaw position of repositioning splint with the aid of digital technique is established. It is proved to be feasible by try-in after multi-data fusion, computer-aided design and computer-aided manufacturing. As is shown in vitro, it is accurate to apply this method in adjusting jaw position. Further clinical trial will be designed to evaluate its clinical effect.

Accuracy of intercuspal occlusion in 3D reconstruction with the dental articulator position method / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the three-dimensional (3D) reconstruction accuracy of the intercuspal occlusion (ICO) of the dental casts, by the dental articulator position method, and provide a reference for clinical application.@*METHODS@#The standard dental casts in ICO were mounted on average values articulator, and five pairs of milling resin cylinders were respectively attached to the base of both the casts. 100 μm articulating paper and occlusal record silicone rubber were used to detect the occlusal contact number between the posterior teeth of casts mounted on articulator in ICO. The occlusal contact numbers NA detected by the two methods were calculated simultaneously, as the reference. After the upper and lower casts were scanned separately, and the buccal data of casts in ICO were scanned with the aid of the dental articulator position, registration was carried out utilizing the registration software. Then the digital casts mounted in ICO as well as the buccal occlusal data were saved in standard tessellation language (STL) format. Geomagic Studio 2013 software was used to analyze the contact number NS between digital upper and lower casts by the "deviation analysis" function. The differences were compared between NS and NA, to evaluate the sensitivity and positive predict value (PPV) of the model scanner to reproduce the occlusal contact with the aid of dental articulator position. The distance DR between the centers of the circles at the top surface of the upper and lower corresponding cylinders was obtained by the three-coordinate measuring system Faro Edge, as the reference value. The Geomagic Studio 2013 software was used to construct the cylinders of digital casts and the distance DM between the centers of the circles at the top surface of the corresponding cylinders were measured, as the test value. The one-sample T test was used to analyze the variable differences between DM and DR.@*RESULTS@#The PPV of reproducing the occlusal contact point was 0.76 and sensitivity was 0.81. The distance error of the opposite cylinder was (0.232±0.089) mm. There was no statistical difference between the feature points 5-5', while there were statistical differences between the other feature points.@*CONCLUSION@#By the dental articulator position method, the model scanner reproduces the occlusal contact point with high sensitivity and PPV, and that meets clinical needs. Meanwhile, the distance between the feature points is greater than the reference value, which will lead to occlusal disturbance, and require clinical grinding.

Comparação clínica entre diferentes técnicas para registro de relação central em indivíduos edêntulos / Clinical comparison between different techniques for //registering a central relation in edentulous individuals

As reabilitações protéticas baseadas em técnicas adequadas podem promover um melhor desempenho, conforto e longevidade à prótese, com o intuito de restabelecer o equilíbrio muscular e articular com o seu uso. Uma das etapas da reabilitação é o registro da relação central (RC) do indivíduo. Para que este registro seja feito, a literatura descreve diversas técnicas aplicáveis, partindo de métodos fisiológicos, guiados ou gráficos. Infelizmente, não existe um consenso se diferentes técnicas para registro da RC oferecem resultados semelhantes. Diante disto, o objetivo deste estudo foi comparar a semelhança entre diferentes técnicas para registro da RC em indivíduos edêntulos, levando em consideração a posição condilar em relação à cavidade glenóide no sentido anteroposterior e o tempo para realização de cada registro, adotando-se uma técnica inicial como controle (técnica do arco gótico extra oral) e uma posição fixada em articulador como referência. Foram incluídos no estudo 12 voluntários (2 homens e 10 mulheres, idade média de 68,58 anos) desdentados bimaxilares usuários de prótese total insatisfatória, considerando critérios de inclusão específicos. Diferentes técnicas foram analisadas pelo posicionamento em um articulador personalizado para mensurar movimentos no sentido anteroposterior, sendo elas: arco gótico extra oral (AGEO), deglutição (D), manipulação frontal associada ao levantamento da língua (MFLL) e arco gótico intra oral (AGIO). Todos os registros foram realizados pelo mesmo operador no mesmo período do dia, com intervalo de 30 minutos entre cada registro e o tempo para realização de cada técnica foi mensurado. Os dados relacionados à confiabilidade das técnicas e o tempo de realização das mesmas foram submetidos à Análise de Variância um fator, seguido do teste de Tukey. Todas as análises foram realizadas com significância de 5%. Considerando as medidas da posição condilar do lado direito, houve diferença estatística (P < 0,05) no registro da técnica D em relação ao registro de AGEO, onde a mandíbula posicionou-se mais anteriorizada. No lado esquerdo, não houve diferença estatística entre os grupos. O registro das técnicas MFLL e AGIO não mostrou diferença estatisticamente significativa em comparação à técnica AGEO em relação a posição de registro da RC em ambos os lados. Em relação ao tempo para realizar cada registro, as técnicas AGEO e AGIO apresentaram diferenças significativas em relação as técnicas D e MFLL, despendendo maior tempo. Pode-se concluir que a técnica D apresentou maior diferença quando comparada às técnicas MFLL e AGIO sobre a posição condilar, onde esta posicionou-se retruída. Os registros de AGEO, MFLL e AGIO não apresentaram diferenças significativas, bem como entre as técnicas D e AGEO. Considerando-se semelhança posição condilar em cada técnica registrada e tempo para execução, as técnicas MFLL mostrou-se adequada, por promover menor tempo clínico ao paciente durante o registro e ser estatisticamente semelhante ao controle. A técnica D também mostrou-se interessante, apresentando-se semelhante ao controle, com erro padrão equilibrado e fisiologicamente confortável ao paciente. Mais estudos precisam ser realizados sobre o comportamento das estruturas do sistema estomatognático quanto quando ao registro de posição condilar protruido ou retruido a longo prazo(AU)

Prosthetic rehabilitation based on appropriate techniques can promote better performance, comfort and longevity to the prosthesis, in order to restore muscle and joint balance with its use. One of the stages of rehabilitation is the registration of the individual's central relationship (CR). For this record to be made, the literature describes several applicable techniques, starting from physiological, guided or graphic methods. Unfortunately, there is no consensus on whether different techniques for recording CR offer similar results. In view of this, the aim of this study was to compare the similarity between different techniques for recording CR in edentulous individuals, taking into account the condylar position in relation to the glenoid cavity in the anteroposterior direction and the time to perform each record, adopting a technique initial as a control (extra oral gothic arch technique) and a position fixed on the articulator as a reference. Twelve volunteers (2 men and 10 women, mean age 68.58 years) were included in the study, toothless bimaxillary users of unsatisfactory complete dentures, considering specific inclusion criteria. Different techniques were analyzed by positioning in a personalized articulator to measure movements in the anteroposterior direction, namely: extra oral gothic arch (AGEO), swallowing (D), frontal manipulation associated with tongue lifting (MFLL) and intra oral gothic arch (AGIO ). All records were made by the same operator at the same time of the day, with an interval of 30 minutes between each record and the time to perform each technique was measured. The data related to the reliability of the techniques and the time they were performed were submitted to one-way analysis of variance, followed by the Tukey test. All analyzes were performed with a 5% significance level. Considering the measurements of the condylar position on the right side, there was a statistical difference (P <0.05) in the registration of technique D in relation to the registration of AGEO, where the mandible was positioned more anteriorly. On the left side, there was no statistical difference between the groups. The registration of the MFLL and AGIO techniques showed no statistically significant difference compared to the AGEO technique in relation to the CR registration position on both sides. Regarding the time to perform each record, the AGEO and AGIO techniques showed significant differences in relation to the D and MFLL techniques, spending more time. It can be concluded that technique D presented a greater difference when compared to the techniques MFLL and AGIO on the condylar position, where it was retracted. The records of AGEO, MFLL and AGIO showed no significant differences, as well as between the techniques D and AGEO. Considering the similarity of the condylar position in each registered technique and time for execution, the MFLL techniques were shown to be adequate, as they promote less clinical time for the patient during registration and are statistically similar to the control. Technique D was also interesting, being similar to the control, with balanced standard error and physiologically comfortable to the patient. More studies need to be carried out on the behavior of the structures of the stomatognathic system regarding the recording of protruded or retracted condylar position at long term(AU)

Restabelecimento da dimensão maxilomandibular em prótese total pela técnica do arco inferior: relato de caso clínico / Reproduction of the maxillo-mandibular dimension in complete denture by the lower arc technique: clinical case report

O registro da relação maxilo-mandibular (RMM) é considerado um passo crítico na confecção de novas próteses totais (PT) pois exige uma precisão técnica capaz de permitir o seu reestabelecimento, de forma confortável e equilibrada com a musculatura oral. O registro é obtido em dois planos, um vertical e outro horizontal: o plano vertical é determinado pela dimensão vertical (DV) e o plano horizontal é estabelecido pela relação cêntrica (RC). Ambos recuperam o suporte labial, altura incisal, linha do sorriso e o corredor bucal de forma natural e personalizada. Esse registro pode ser obtido, iniciando pelo arco inferior, seguindo a fisiologia e anatomia orofacial. Nessa técnica, considerase três princípios fisiológicos: crista alveolar, situada sobre o rebordo alveolar, musculatura relacionada que determinará o corredor bucal e posição lingual do rodete e a linha úmida do lábio inferior que determinará a altura do rodete inferior. Dessa forma, este trabalho tem por objetivo descrever por meio de condução de caso clínico a técnica de restabelecimento da RMM em paciente edentado bimaxilar iniciando pelo arco inferior(AU)

The maxillo-mandibular relation (MMR) is considered a critical step in the preparation of new complete denture (CD), since it requires a technical precision capable of allowing its reestablishment, in a comfortable and balanced way with the oral musculature. The register is obtained in two planes, one vertical and one horizontal: the vertical plane is determined by the vertical dimension (VD) and the horizontal plane is established by the centric relation (CR). Both recover the lip support, incisal height, smile line and buccal corridor in a natural and personalized way. This record can be obtained, beginning with the lower arch, following the physiology and orofacial anatomy. In this technique, three physiological principles are considered: alveolar crest, located on the alveolar ridge, related musculature that will determine the buccal corridor and the lingual position of the wax rim and the humid line of the lower lip which will determine the height of the lower wax rim. Thus, this study aims to describe, by way of conducting a clinical case, the technique of restoration of RMM in a bimaxillary edentulous patient starting with the inferior arch(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.

Accuracy comparison of buccal bite scans by five intra-oral scanners

PURPOSE: The purpose of this study was to investigate the accuracy of the interocclusal relationship between upper and lower teeth according to the buccal interocclusal record scan using various intraoral scanner systems. MATERIALS AND METHODS: The upper and lower full arch Models with normal occlusion were scanned with 5 intraoral scanners (Cerec Omnicam, CS3500, iTero, Trios, True Definition). Buccal interocclusal record scan was taken only at the left side while occlusion was intentionally raised by 1 mm, 2 mm, 3 mm, and 4 mm with metal cylinder core embedded within polyvinylsiloxane bite registration material at the right molar region. The superimposition analysis was done to evaluate overall three-dimensional deviation and cross-section analysis was done to evaluate the degree and the direction of deviation of interocclusal relationship. RESULTS: From the superimposition study, Cerec Omnicam showed the least deviation (165.5 µm) and CS3500 (369.0 µm) showed the largest (P < 0.01). And the deviation was greater in 3, 4, 2 mm group than 1 mm (P < 0.01). From the cross-section study, Cerec Omnicam showed the farthest deviation (−242.8 µm) and CS3500 showed the closest deviation (312.5 µm) and a significantly high value was shown in 3 mm group. CONCLUSION: Every intraoral scanner has different accuracy in reproducing interocclusal relationship.

Fabrication of complete dentures for a patient with odontogenic myxoma: A case report / 대한치과보철학회지

Odontogenic myxoma of the jaws is a rare benign odontogenic tumor. In this case, a 61-year-old male patient had a chief complaint about maxillary anterior gingival mass and excisional biopsy result confirmed odontogenic myxoma. The clear acrylic resin custom tray was designed to minimize displacement of flabby tissue which remained after the surgery. Neutral zone and external impression technique could provide satisfactory result in terms of denture stability and retention during jaw relation record and wax denture try-in procedure. This clinical report describes fabrication of complete dentures for a patient with odontogenic myxoma in regard to flabby tissue and neutral zone.

A simple technique for impression taking of teeth and functionally generated paths

The objective of this case report is to introduce a simple technique for simultaneously taking a closed-mouth impression and functionally generated path (FGP) for a full coverage crown restoration. A monolithic zirconia crown was the restoration of choice. An alginate impression of the abutment tooth was taken to fabricate a custom-made closed-mouth impression tray covering the abutment tooth and the adjacent teeth. The tray had an FGP table and an abutment tray in cameo and intaglio surfaces, respectively. The impression was taken with silicone impression material after adjusting the abutment tray and inscribing the FGP using self-curing acrylic resins. Plaster casts were made from the impression, and a zirconia crown was fabricated. The crown was cemented to the abutment tooth with minimal adjustments. This simple technique resulted in a well-fitting crown that accounted for mandibular movements. Using the custom closed-mouth impression tray incorporating an FGP table simultaneously aids in fabricating an accurately fitting restoration that incorporates harmonious mandibular movements using a single impression capture.

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.

Accuracy of several implant bite registration techniques: an in-vitro pilot study

PURPOSE: This study evaluated the accuracies of different bite registration techniques for implant-fixed prostheses using three dimensional file analysis. MATERIALS AND METHODS: Implant fixtures were placed on the mandibular right second premolar, and the first and second molar in a polyurethane model. Aluwax (A), Pattern Resin (P), and Blu-Mousse (B) were used as the bite registration materials on the healing abutments (H) or temporary abutments (T). The groups were classified into HA, HP, HB, TA, TP, and TB according to each combination. The group using the bite impression coping was the BC group; impression taking and bite registration were performed simultaneously. After impression and bite taking, the scan bodies were connected to the lab analogs of the casts. These casts were scanned using a model scanner. The distances between two reference points in three-dimensional files were measured in each group. One-way ANOVA and Duncan's test were used at the 5% significance level. RESULTS: The smallest distance discrepancy was observed in the TB group using the temporary abutments. The Blu-Mousse and HP groups showed the largest distance discrepancy. The TB and BC groups showed a lower distance discrepancy than the HP group (P=.001), and there was no significant difference between the groups using the temporary abutments and healing abutments (P>.05). CONCLUSION: Although this study has limitations as an in-vitro investigation, the groups using the temporary abutments to hold the Blu-Mousse record and bite impression coping showed greater accuracy than the group using the healing abutments to hold the pattern resin record.

Integrating 3D facial scanning in a digital workflow to CAD/CAM design and fabricate complete dentures for immediate total mouth rehabilitation

PURPOSE: To integrate extra-oral facial scanning information with CAD/CAM complete dentures to immediately rehabilitate terminal dentition. MATERIALS AND METHODS: Ten patients with terminal dentition scheduled for total extraction and immediate denture placement were recruited for this study. The patients were submitted to a facial scanning procedure using the in-office PritiMirror scanner with bite registration records in-situ. Definitive stone cast models and bite records were subsequently submitted to a lab scanning procedure using the lab scanner (iSeries DWOS; Dental Wings). The scanned models were used to create a virtual teeth setup of a complete denture. Using the intra-oral bite records as a reference, the virtual setup was incorporated in the facial scan thereby facilitating a virtual clinical evaluation (teeth try-in) phase. After applying necessary adjustments, the virtual setup was submitted to a CAM procedure where a 5-axis industrial milling machine (M7 CNC; Darton AG General) was used to fabricate a full-milled PMMA immediate provisional prosthesis. RESULTS: Total extractions were performed, the dentures were immediately inserted, and subjective clinical fit was evaluated. The immediate provisional prostheses were inserted and clinical fit, occlusion/articulation, and esthetics were subjectively assessed; the results were deemed satisfactory. All provisional prostheses remained three months in function with no notable technical complications. CONCLUSION: Ten patients with terminal dentition were treated using a complete digital approach to fabricate complete dentures using CAD/CAM technology. The proposed technique has the potential to accelerate the rehabilitation procedure starting from immediate denture to final implant-supported prosthesis leading to more predictable functional and aesthetics outcomes.

Levantamento de marcas de mordidas humanas em vítimas de violência periciadas no Instituto Médico Legal de Feira de Santana-BA, entre 2007 e 2014 / Bites brand survey on human violence victims examined in the Legal Medical Institute of Feira de Santana-BA, between 2007 and 2014

Objetivo: Descrever a prevalência de marcas de mordidas em vítimas de violência periciadas no Instituto Médico Legal de Feira de Santana no período de 2007 até 2014, levando em consideração a análise do perfil sociodemográfico das vítimas, a relação destas com os supostos agressores, bem como fatores inerentes às particularidades da violência, características da mordida e região do corpo atingida. Métodos: Estudo de casuística, de caráter exploratório com base em dados secundários, produzidos a partir das perícias realizadas por peritos odontolegistas registradas em laudos arquivados no Instituto Médico Legal (IML), no período de 2007 à 2014. Resultados: Os resultados apontam um maior índice de vítimas do sexo feminino (78,1%), entre 20-60 anos (53,1%), faiodermas, estudantes (28,6%) e naturais de Feira de Santana (56,2%). A região de cabeça e pescoço (29,2%) e membros superiores (29,2%) tiveram destaque nas agressões e a maioria das vítimas apresentaram mais de uma lesão, apresentando-se clinicamente como escoriações (34,2%) e equimoses (31,6%). Em nenhum dos casos houve tentativa de identificação do agressor pela mordida. Conclusão: Desse modo, conclui-se que a maior parte das vítimas de violência física que apresentaram lesão provocada por mordida humana era do sexo feminino, faioderma e adultos. Os supostos agressores na maioria dos casos tem ou tiverem um vínculo conjugal com a vítima. As marcas de mordidas foram predominantes na região de cabeça e pescoço e membros superiores. Como manifestação clínica destacou-se as escoriações e equimoses.(AU)

Aim: To describe the prevalence of bitemarks in victims of physical violence logged in forensics reports at the Legal Medical Institute (IML) of Feria de Santana, BA, Brazil, between 2007 and 2014, taking into account the analysis of the sociodemographic profile of the victims, their relationships with their aggressors, as well as factors inherent to the particularities of the violence, characteristics of thebite, and the region of the body that was affected. Methods: Exploratory study of the cause, based on secondary data, identified in forensics reports carried out by dental forensics experts, duly recorded in reports at the IML from 2007 to 2014. Results: The results point out a higher index of female victims (78.1%), between 20 and 60 years of age (53.1%), light-skinned black students (28.6%), and natives of the city of Feira de Santana (56.2%). The head and neck region (29.2%) and upper limbs (29.2%) were the most commonly attacked regions, and the majority of victims presented more than one lesion, appearing clinically as excoriations (34.2%) and ecchymosis (31.6%). None of the cases attempted to identify the aggressor through the bitemark. Conclusion: Therefore, it can be concluded that the majority of the victims of physical violence who presented lesions provoked by human bites were female, light-skinned back, adults. The supposed aggressors, in the majority of cases, have or had some form of marital relationship with the victim. Bitemarks were predominantly found in the head and neck region and upper limbs. Excoriations and ecchymosis stood out as the main clinical manifestations.(AU)

Paralelismo entre plano oclusal y plano de Camper / Parallelism between the occlusal plane and the Camper's line

Objetivo: El propósito de este estudio fue verificar la relación de paralelismo entre el plano oclusal y 3 definiciones de plano de Camper en una población eugnásica chilena. Material y métodos Estudio transversal. Se seleccionaron 60 adultos jóvenes chilenos eugnásicos (32 hombres y 28 mujeres) entre 18 y 35 años. Se utilizaron telerradiografías de perfil digitales y fotografías faciales laterales estandarizadas. Se superpuso la cefalometría en las fotografías laterales con el programa Quick-Ceph®. Los planos de Camper se trazaron desde 3 diferentes puntos de inicio en el tragus (superior, medio e inferior) hacia el punto más inferior del ala de la nariz. Se midieron los ángulos formados entre el plano oclusal y los 3 planos de Camper resultantes con el programa Screen Protractor®. Resultados El análisis ANOVA muestra diferencias significativas entre los 3 ángulos. El ángulo promedio entre el plano de Camper medio y el plano oclusal fue -0,63°. En hombres, el plano de Camper medio fue más paralelo al plano oclusal (1,11°) y en mujeres el plano de Camper superior fue el más paralelo con el plano oclusal (1,39°). Conclusión El paralelismo fue verificado para el plano de Camper medio en hombres y para el plano de Camper superior en mujeres.

Objective: The aim of this study was to verify the parallelism between the occlusal plane and three different Camper's line definitions in a Chilean eugnathic population. Material and methods Cross-sectional study was conducted on 60 Chilean eugnathic young adults (32 males and 28 females) between 18 and 35 years old. Lateral digital standardised cephalometric radiographs and facial photographs were used. The cephalometric analysis was superimposed over the lateral photographs with Quick-Ceph® software. The Camper's line was traced from three different starting points at the Tragus (upper, middle and lower) to the lowest point below the nostrils. The angles obtained between the occlusal plane and the resulting Camper's lines were measured with Screen Protractor® software. Results The ANOVA test showed significant differences for the obtained angles. The mean parallelism between the medium Camper's line and the occlusal plane was -0.63°. In males, the medium Camper's line was more parallel to the occlusal plane (1.11°), and for females, the upper Camper's line was the most parallel to the occlusal plane (1.39°). Conclusion The parallelism was verified for the medium Camper's line in males, and for the upper Camper's line in females.

Relación entre el espesor del registro interoclusal en céntrica y el error oclusal en la posición retruída de contacto en el articulador semiajustable de tipo arcon / Relation between the thickness of the interocclusal centric registration and occlusal error in the retruded contact position in an arcon semiadjustable articulator

Objetivo. Relacionar el espesor del registro interoclusal en céntrica con el error oclusal en la posición retruída de contacto en el articulador semi ajustable, tipo arcon. Materiales y métodos. Se utilizó un juego de modelos de 42 alumnos de la asignatura de Oclusión de una universidad particular, con oclusión clase I, dentición natural, completa hasta segunda molar, libres de signos-síntomas de trastornos temporomandibulares, y con contacto prematuro unilateral y posterior perfectamente verificable. Para reproducir la posición retruída de contacto, se tomaron tres registros de relación céntrica (espesores de 1, 2 y 3 mm). Se observaron tres contactos prematuros a los que se les denominó A1, B1, C1 de acuerdo a los tres registros usados, su ubicación se registró usando folio de 8 µm y cinta de 12 µm. Se cuantificó el error oclusal usando un calibrador digital. Resultados. El error oclusal fue de 0,0 mm,0,46 mm, y 2,01 mm, para el registro A, B y C, respectivamente. El test de Friedman determinó que hay diferencias significativas en el error oclusal presentado por los tres tipos de registro (p=0,00). La prueba de signo de rangos de Wilcoxon, demostró que existen diferencias significativas en el error oclusal ocurrido entre los pares de registros...

Objective. To relate the thickness of the centric interocclusal record with occlusal error in retruded contact position in arcon type se-miadjustable articulator. Materials and methods. A set of 42 casts of occlusion students were taken from a private university presenting occlusion Class I, natural and complete dentition to second molar, free of signs and symptoms of temporomandibular disorders, and with premature and unilateral contact perfectly verifiable. To reproduce the retruded contact position three centric relation records were taken with different thicknesses of 1. 2 and 3 mm. Tree premature contacts were observed and were called A1, B1, C1, according to the three records used, its location were recorded using foil tape of 8 and 12 pm. Occlusal error was quantified using a digital caliper. Results. The occlusal error was 0.0 mm, 0.46 mm and 2.01 mm, for the record A, B and C, respectively. Friedman test determined a significant difference in occlusal errors introduced by the three record types (p = 0.00). Wilcoxorf s Sign Test Rank showed significant differences in the occlusal error that occurred between pairs of records A...

Stability of phonetics to determine the horizontal jaw relation in healthy adults / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The aim of this study was to compare the mandibular position when speaking with the intercuspal position and to check the stability of phonetics when determining the horizontal jaw relation in healthy adults.</p><p><b>METHODS</b>A total of 19 healthy volunteers were recruited. Seven Chinese letters, namely, /xi/, /er/, /yi/, /ci/, /mi/, /ni/, and /ri/, were chosen in the test. O-bite was used to record the mandibular position when speaking these letters. A full-adjusted articulator was used to find the mandibular position during speech, and the mandibular position was measured using a vernier caliper. The mandibular position during speech with intercuspal position was compared in both anterior-posterior and left-right directions of the horizontal plane. Multi-factor analysis of variance was conducted for the statistical analysis of the effect of objects and letters on the mandibular position.</p><p><b>RESULTS</b>1) The mandibular position was in front of the intercuspal occlusion position when speaking all seven letters, and almost no deviation was observed in the left and right directions (the mandibular position value of 82% was in the range of 0.5 mm). 2) Different objects had different mandibular positions during speech, whereas different letters did not. The distance between the centric relation position and the intercuspal position had a positive correlation with the range of the mandibular position during speech.</p><p><b>CONCLUSION</b>The mandibular position was in front of the intercuspal position when speaking all seven words in the test. In the same object, the mandibular position was stable during speech.</p>