Evaluation of the occlusal contact area of molar dental implants comparing two different thicknesses (16 µm and 200 µm) of articulating occlusal papers and forces (200 and 250 N): a pivot in vitro study

Introduction: The goal of this pilot study was to evaluate the differences between checking occlusion on implants crowns using 16 or 200 µm thickness of articulating occlusal paper, and to compare the stained occlusal area between the groups after bite forces of 200 and 250 N. Methods: It was included 10 casts of articulated-type IV gypsum, 10 NiCr crowns, articulating occlusal papers (16 µm and 200 µm thick), and a compression test machine. Compressive forces (200 and 250 N.mm) were applied on models, to check the occlusal contact area of fixed and cemented crowns. The contact areas on the crowns were measured through images obtained by the scanning electron microscope. Statistical tests were performed considering the significant level of 5% (p≤0.05). Results: The stains found using 200 µm of articulating paper were higher than those with 16 µm, independent of the force applied. However, the stains obtained in lower teeth with different strengths (200 and 250N) marked with 16 µm articulating paper were not possible to score. The articulating paper variable had significant statistical results (p=0.002), while the variables force (p=0.443) and articulating paper-force interaction (p=0.607) were not significant. The mean area found in staining using the 200 µm and 16 µm papers was, respectively, 8.3380 mm2 and 3.4759 mm2. Conclusion: It was possible to confirm that 200 µm of articulating occlusal paper showed better and significant results to stain the occlusal area, permitting a more accurate adjustment independent of the force applied.

Prosthetic articulator-based implant rehabilitation virtual patient: A technique bridging implant surgery and reconstructive dentistry.

This technique report describes a fully digital workflow to create a prosthetic articulator-based implant rehabilitation (PAIR) virtual patient for complete-arch or complete-mouth implant rehabilitation. This workflow uses a custom gothic arch tracer during the cone beam computed tomography (CBCT) scan and a 3-dimensional virtual facebow when superimposing data. The PAIR virtual patient possesses reliable centric relation and vertical dimension of occlusion and is compatible with virtual articulators. Computer-aided implant planning and a digital prosthetic design can be seamlessly integrated by using this virtual patient.

Study on the reconstruction of a four-dimensional movement model and the envelope surface of the condyle in normal adults.

The objective of this study was to reconstruct the envelope surface of the condyle and the four-dimensional trajectory model in mandibular border movement in normal adults. Eleven healthy subjects were selected as volunteers. Cone-beam computed tomographic (CBCT) scanning was performed on the volunteers. The three-dimensional (3D) movement path of the mandible was recorded using a virtual articulator (PN-300), which was based on a 3D model of the mandible. We used Proplan CMF 3.0 (Materialise) software to perform this from the DICOM data generated by CBCT scans. The distance of condylar movement was measured in this model during volunteers' mouth opening, protrusion, and lateral excursions. The envelope surface of the condyle was reconstructed by merging a functional condylar surface at each recording moment during the movement of the whole border. In the mandibular digital models, the condyle moved downward firstly, and moved upward to the position of maximum mouth opening. The condyle moved forward and downward during protrusion. The working condyle rotated slightly and the non-working condyle moved forward, downward, and inward during lateral excursions. The mean (SD) movement distance of 11 subjects was 19.04 (4.37) mm during mouth opening (including downward and upward) and 9.75 (2.38) mm during protrusion. During lateral excursions the mean (SD) movement distance of the working condyle was 2.87 (1.13) mm, the mean (SD) movement distance of the non-working condyle was 10.85 (3.25) mm. The envelope surface of healthy volunteers showed a double-peak pattern. The envelope surface of the condyle and four-dimensional movement model can be reconstructed by merging the trajectory of the mandible recorded from the novel virtual articulator PN300 and a 3D image of the mandible.

Update on the parameters influencing the adjustment of the sagittal and transversal condylar inclination of dental articulators.

OBJECTIVES: The literature review aimed to compile and summarize the results of research relating to the recordings of condylar displacements obtained with extraoral devices, to guide clinicians to set dental (virtual) articulator parameters. The meta-analysis was undertaken to assess the sagittal condylar inclination (SCI) and transversal condylar inclination (TCI, also known as Bennett angle) values according to horizontal reference planes, movement studied, and patient characteristics: dental status, interocclusal relationship, skeletal pattern, and signs and symptoms of temporomandibular disorders (TMD). DATA SOURCES: A bibliographic search was conducted in the three following electronic databases: MEDLINE, EMBASE, and Cochrane Library and Best Evidence. The review was restricted to trials involving participants meeting the following criteria: (1) adult, (2) no previous surgery in the temporomandibular region, and (3) no serious comorbidity conditions. Descriptive statistics were calculated for all study groups and were compared by applying a one-way ANOVA. CONCLUSION: All 20 articles selected corresponded to a total of 933 subjects evaluated. The recording devices and horizontal reference planes had a significant impact on the SCI values. Age, dental status, and the presence of symptoms and signs of TMD in subjects had no influence on SCI values, unlike Angle class II, division 2, the class II sagittal pattern, or the increased vertical skeletal pattern SCI parameters (P < .05). The mean TCI value was 8 degrees and was independent of individual patient characteristics and the extraoral recording device used. For accurate kinematic simulation, the patient's personal plane of reference must be transferred to the system.

Application of the Digital Articulator in Surgery-First Approach.

ABSTRACT: Orthognathic surgery with surgery-first concept inevitably leads to an increase in posterior vertical dimension and anterior mandibular movement, causing a relapse. This case report introduces a digital technique for predictable surgical outcome in mandibular setback with the surgery-first orthognathic concept using digital articulator. Intraoral scans and a digital articulator were used to simulate the mandibular position after surgery and to predict postoperative increase in vertical dimension and its expecting forward movement of mandibile. This was incorporated in surgical planning. Sequential cone-beam computed tomography evaluation showed stable condylar position at 3 and 6 months after surgery. Thus, a digital articulator can be used to simulate the surgical outcome and to predict postsurgical increase in vertical dimension for better treatment planning.

Correção de Hiperplasia Hemimandibular com cirurgia de estágio único e uso de prototipagem: relato de caso / Correction of Hemimandibular Hyperplasia with single-stage surgery and use of prototyping: Case Report

Introdução:O tratamento da assimetria facial causada pela hiperplasia hemimandibularvemsendodebatidohádécadase, ainda assim,existem algumas controvérsias quanto aomelhor manejo dessacondição. Relato de caso:Revisão de literatura acerca das abordagens cirúrgicas descritas, e, apresentação de caso clínico de uma pacientecomassimetriafacial. Foram realizadas a cirurgiadepredictibil idadenoarticuladorsemi-ajustáveleprototipagem dos maxilares feita a partir de tomografia computadorizada. A paciente foi submetida a cirurgia ortognática com nivelamento da basilar mandibular e condilectomia no mesmo tempo cirúrgico. Considerações finais:Após acompanhamento por 48 meses, a paciente não apresenta recidiva e segue com a oclusão estável. Segue, também, sem dor nas articulações temporomandibulares. Dessaforma, foi alcançado um aspecto mais harmonioso da face, uma vez que a paciente se queixava de que a assimetria causava transtornos sociais a ela... (AU)

Introduction: The treatment of facial asymmetry caused by hemimandibular hyperplasia has been debated for decades and, even so, there are some controversies regarding the best management of this condition. Case report: Literature review about the surgical approaches described, and presentation of a clinical case of a patient with facial asymmetry. Predictability surgery was performed on the semi-adjustable articulator and prototyping of the jaws using computed tomography. The patient underwent orthognathic surgery with leveling of the mandibular basilar and condylectomy at the same surgical time. Final considerations: After 48 months of follow-up, the patient has no recurrence and continues with stable occlusion. There is also no pain in the temporomandibular joints. In this way, a more harmonious aspect of the face was achieved, since the patient complained that the asymmetry caused social disorders to her... (AU)

Registering Maxillomandibular Relation to Create a Virtual Patient Integrated with a Virtual Articulator for Complex Implant Rehabilitation: A Clinical Report.

The virtual patient, a unique computer simulation of the patient's face, teeth, oral mucosa, and bone, provides an extraordinary mechanism for digital dental implant surgery planning and prosthetic design. However, the seamless registration of digital scans with functional information in the context of a virtual articulator remains a challenge. This report describes the treatment of a 47-year-old male with full-mouth guided immediate implant placement and immediate loading of CAD/CAM interim prostheses. Utilizing a novel digital workflow, a multifactorial registration of the vertical dimension of occlusion, centric occlusion, and facebow record were completed digitally and paired within a digital articulator. Utilizing this innovative approach, a complex treatment plan and procedure was executed smoothly with a successful prosthetic outcome demonstrating good fit, occlusion, esthetics, and patient reported satisfaction.

Comparison of the postoperative and follow-up accuracy of articulator model surgery and virtual surgical planning in skeletal class III patients.

The aim of this study was to evaluate the postoperative and follow-up accuracy of using an intermediate occlusal splint between articulator model surgery (AMS) and virtual surgical planning (VSP) in double-jaw operations. Thirty skeletal class III patients were randomly allocated to have AMS or VSP. In the AMS group surgical planning was done through conventional articulator model surgery, and an intermediate occlusal splint made of acrylic resin was used. In the VSP group the surgical simulation was done virtually, and the same intermediate splint was used in the software and then fabricated using rapid prototyping technology. Preoperatively, one week postoperatively, and 1∼2-years later we obtained follow-up cone-beam computed tomographic (CT) images of each patient. Absolute linear differences between planned and actual outcomes, as well as planned and follow-up outcomes, were evaluated. There was no significant difference in either postoperative accuracy or follow-up accuracy between the methods, and there was no significant difference in the rate of skeletal relapse. Planning transfer by intermediate splint might therefore be the dominant factor in the final inaccuracies. The potentially greater accuracy of VSP may be realised with the help of new positioning devices instead of an intermediate splint.

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)

Quantification of the inaccuracy of conventional articulator model surgery in Le Fort 1 osteotomy: evaluation of 30 patients controlled by the Orthopilot® navigation system.

Occlusal splints are commonly used to position the maxilla during traditional orthognathic surgery. We aimed to quantify the inaccuracy of the maxillary positioning (in three dimensions) in traditional model surgery with the Orthopilot® navigation system. Thirty Le Fort I osteotomies were made using a standard technique. The position of the maxilla was recorded by the navigation system and defined by three values of translation and three of rotation. The recorded data were compared with the planned data. The accuracy of positioning was classified in distinct classes with three major criteria (conformity, non-conformity, and failure) according to the discrepancy. The positioning of the maxilla was in conformity with operative planning in 3/30 of our Le Fort I osteotomies (95% CI 2% to 27%) and in failure in 22/30 (95% CI 54% to 88%). The dispersion of the discrepancy was more important in the sagittal plane, particularly for the sagittal rotation and for the back-front translation, which reflected greater inaccuracy in this plan. The frontal orientation of the maxilla was better controlled. The risk of maxillary malposition was proportional to the planned maxillary advancement.

Terapia combinada de láser diódico y plano desprogramador neuromuscular en pacientes con disfunción temporomandibular / Combined therapy of diode laser and neuromuscular deprogrammer splint in patients with temporomandibular disorder

La desprogramación neuromuscular juega un papel importante en el tratamiento de la disfunción temporomandibular, uno de los principales inconvenientes es el periodo prolongado del tratamiento, lo cual influye en la aceptación del paciente o el abandono del tratamiento. El diagnóstico es crucial para planificar el tratamiento ya que cubre una amplia gama de variables para tratarlo, por lo que en este caso es un paciente dolicofacial, con problemas de disfunción temporomandibular de origen muscular, por lo cual se optó por utilizar laserterapia de bajo nivel como coadyuvante de tratamiento, dando como resultado una mejor aceptación y colaboración de la desprogramación del paciente en un periodo de tiempo más corto (AU)

Neuromuscular deprogramming plays an important role in the treatment of temporomandibular dysfunction, one of the main drawbacks is the prolonged period of treatment, which influences the acceptance of the patient or the abandonment of treatment. The diagnosis is crucial to plan the treatment since it covers a wide range of variables to treat it, so in this case it is a dolichofacial patient, with problems of temporomandibular dysfunction of muscular origin, which is why we chose to use low-level laser therapy, level as a coadjutant of treatment, resulting in a better acceptance and collaboration of the deprogramming of the patient in a shorter period of time (AU)

Guarda oclusal gnatológica: técnica de elaboración, procesado y polimerizado por microondas / Gnathological occlusal guard: technique of elaboration, processing and polymerization by microwaves

Los trastornos temporomandibulares (TTM) constituyen un problema en la población en general cuyos signos y síntomas tienen un carácter multifactorial que debe ser abordado de manera interdisciplinaria para poder brindar una mejor oportunidad de éxito y estética en los tratamientos. Las guardas oclusales forman parte del tratamiento en los TTM, se deben conocer sus indicaciones, contraindicaciones, ventajas y desventajas, debido a que las guardas oclusales cumplen ciertas funciones y objetivos. La guarda oclusal elaborada por la técnica de polimerización en microondas (GOTMI) reduce signifi cativamente el tiempo de elaboración en el laboratorio, proporciona un aparato de alta calidad y baja porosidad. La GOTMI es un aparato que proporciona un método indirecto y no invasivo modifi cando la oclusión, recuperando el tejido u órganos dentales perdidos, reorganiza la actividad refl eja neuromuscular, relaja la musculatura, promueve el reposicionamiento del disco articular, protege los dientes, oclusión y estructuras de sostén periodontal, además de mejorar la estética y la autoestima del paciente. La GOTMI disminuye el dolor en la ATM y la neuromusculatura, proporciona alivio a las cefaleas tensionales, elimina las interferencias oclusales, es un distribuidor de fuerzas oclusales, además de provocar un mayor número de contactos de igual intensidad de fuerza contra la superfi cie oclusal en todos los dientes. Existen varios métodos para la confección de las guardas oclusales, en el presente trabajo se describe la elaboración de una guarda oclusal programada con los principios de oclusión orgánica. La técnica de polimerización por microondas es innovadora debido a que este proceso consiste en la generación de calor dentro de la resina mediante ondas electromagnéticas producidas por un generador llamado magnetrón. Las moléculas de metilmetacrilato son capaces de orientarse por el campo electromagnético a una frecuencia de 2,450 MHz, y cambian su dirección cinco billones de veces por segundo aproximadamente, lo que implica numerosas colisiones intermoleculares y causa una rápida polimerización (AU)

Temporomandibular disorders (TMD) are a problem in the general population whose signs and symptoms have a multifactorial character that must be addressed by an interdisciplinary team to provide a better chance of success and aesthetic treatments. Occlusal guards are part of TMD treatment, you should know the indications, contraindications, advantages, and disadvantages, because the occlusal guards perform certain functions and objectives. The occlusal guard by Iztacala modifi cation provides an indirect and noninvasive method modifying occlusion, recovering the lost dental tissue or organs, reorganizes the neuromuscular refl ex activity, relaxes the muscles, promotes articular disc repositioning, protecting the teeth and supporting occlusion structures, it also improves aesthetics and self-esteem. The occlusal guard Iztacala modifi cation has the advantage of decreasing TMJ pain, provides relief to tension headaches, elimination of occlusal interferences, is a distributor of occlusal forces as well as causing a greater number of contacts equal intensity of force against the occlusal surface of all teeth. There are several methods for the fabrication of occlusal guards, in this paper the development of an occlusal guard programmed with the principles of organic occlusion is described, using as a basis a rigid acetate and acrylic for programming, in addition to providing your cosmetic use and function. The acquisition or denial of treatment with an occlusal splint depends on the choice, preparation, occlusal guard adjustment and patient cooperation (AU)

Tratamiento de Clase II primera división, con mordida abierta anterior y alteración de la articulación temporomandibular / Class II treatment, first division, with anterior open bite and temporomandibular joint alteration

El éxito de todo tratamiento ortodóncico, radica en buscar la estabilidad a largo plazo, razón por la cual el sistema debe funcionar correctamente y, para ello, todos los elementos que conforman el sistema estomatognático y su musculatura, deberían sincronizarse con las articulaciones temporomandibulares (ATM), guiados por una correcta relación oclusal, tanto en oclusión como en desoclusión, siendo determinantes las óptimas relaciones dentarias para obtener la adecuada posición; cóndilo; disco; eminencia y claves para la estabilidad neuromuscular, dentaria y articular(AU)

The success of every orthodontic treatment lies upon looking for long term stability, this is the reason why the system must work correctly, and for that every element that shapes the stomatognathic system and its musculature should be synchronized with the temporomandibular joints (TMJ), guided by a correct occlusal relation, both in occlusion and desocclusion, being determinants the optimal dental relations to obtain the adequate position, condyle, disc, eminence, and keys for the neuromuscular, dental and articular stability (AU)

[Maxillo-facial surgery in skeletal Class II: repercussions on the temporo-mandibular joints]. / La chirurgie des cas de classe II et ses répercussions sur les articulations temporo-mandibulaires.

These interventions usually aimed at the correction of the skeletal discrepancy by mandibular retrognatism with an advancement of the distal portion of the mandible after mandibular osteotomy. The position of the condyle is determined during the osteosynthesis with miniplates. Condyles are set back in relation with the supine position of the patient and the weakness of his (her) curarized muscle. All studies show that surgery of mandibular advancement causes a lateral, torque and backward movement of the condyles, all harmful to the condyles. Factors that predispose to condylar resorption are "the patient": a woman, young (between 15 and 40), high mandibular angle, with a history of temporo-mandibular disorders and surgical overload applied to the condyles. What are the possible solutions to avoid failures? Patient preparation before surgery and surgery simulation with an articulator, condylar position control during surgery, working with surgeons to achieve a condylar portion stabilization system (with the CAD), quickly set up a mobilization of the mandible by physiotherapy.

The face bow is irrelevant for making prostheses and planning orthognathic surgery.

BACKGROUND: The author addresses whether the face bow is irrelevant for all types of prosthetic work and for planning orthognathic surgery. METHODS: The author searched electronic databases to find studies whose investigators used the strongest clinical evidence (that is, randomized clinical trials) and studies whose investigators incorporated the use of cinefluorography. The author found 13 studies and 1 Internet video that provided strong evidence to support the irrelevancy of the face bow transfer. RESULTS: Evidence indicates that the face bow has nothing to do with speech, the fit and comfort of the prostheses, ridge morphology, facial contours, the color of the teeth and denture bases, the arrangement of the artificial teeth, chewing efficiency stability, and the psychological aspects of prosthodontic treatment. The cinefluorographic example showed that there was no condylar axis of rotation during functional activity, a sawing action of the mandibular incisors during the incising of toast and the mandible moving in a back and forth, rocking chair-like movement during functional activity. CONCLUSIONS: Eliminating the face bow transfer reduces the patient's chair time and the dentist's overhead expenses. The author found evidence in the results of randomized controlled trials and an online video that justify eliminating the use and teaching of the 133-year-old technique known as the face bow transfer. PRACTICAL IMPLICATIONS: Patients expect their physicians and dentists to perform only treatment procedures that are essential. The findings of this study show that the face bow transfer treatment procedure is not absolutely necessary to mount dental models on an articulator. Students', professors', schools', patients', and taxpayers' time and money can be saved by no longer teaching this 133-year-old treatment procedure.

Precision of a CAD/CAM-engineered surgical template based on a facebow for orthognathic surgery: an experiment with a rapid prototyping maxillary model.

OBJECTIVE: We examined the precision of a computer-aided design/computer-aided manufacturing-engineered, manufactured, facebow-based surgical guide template (facebow wafer) by comparing it with a bite splint-type orthognathic computer-aided design/computer-aided manufacturing-engineered surgical guide template (bite wafer). STUDY DESIGN: We used 24 rapid prototyping (RP) models of the craniofacial skeleton with maxillary deformities. Twelve RP models each were used for the facebow wafer group and the bite wafer group (experimental group). Experimental maxillary orthognathic surgery was performed on the RP models of both groups. Errors were evaluated through comparisons with surgical simulations. We measured the minimum distances from 3 planes of reference to determine the vertical, lateral, and anteroposterior errors at specific measurement points. The measured errors were compared between experimental groups using a t test. RESULTS: There were significant intergroup differences in the lateral error when we compared the absolute values of the 3-D linear distance, as well as vertical, lateral, and anteroposterior errors between experimental groups. The bite wafer method exhibited little lateral error overall and little error in the anterior tooth region. The facebow wafer method exhibited very little vertical error in the posterior molar region. CONCLUSIONS: The clinical precision of the facebow wafer method did not significantly exceed that of the bite wafer method.

Avances en la planificación de casos tratados con ortodoncia y cirugía ortognática. Parte 2 / Advances in planning the cases treated with orthodontics and orthognathic surgery. Part 2

En estos artículos los autores presentan una nueva línea de instrumentos de precisión usados en el procedimiento de laboratorio para la preparación de modelos set-up, corrección de modelos set-up y cirugía de modelos de acuerdo con el plan de tratamiento ortodóncico y quirúrgico. Se describen en este artículo el Set-Up Model Maker (SUM), el Occlusal Plane Reference (OPR) y el Surgical Model Accuracy Device (SMAD), y se explica su utilización a través del tratamiento de un caso clínico con clase III esquelética y mordida abierta...

In these articles the authors introduce a new line of precision instruments used in the laboratory procedure for set-up models preparation, set-up models correction and model surgery according to the orthodontic and surgery treatment plan. The Set-Up Model Maker (SUM), the Occlusal Plane Reference (OPR) and the Surgical Model Accuracy Device (SMAD) are described in this article, and its use is explained through the case report of a treatment of a skeletal class III case with open bite...

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...