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Clinical Oral Investigations Apr 2024Reconstruction of a three-dimensional jaw position determined by a bite recording is an important aspect of prosthetic therapy. Different materials are used for this...
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.
Topics: Humans; Jaw Relation Record; Mandible; Dental Articulators; Vertical Dimension; Silicones
PubMed: 38556612
DOI: 10.1007/s00784-024-05637-y -
The Journal of Prosthetic Dentistry Mar 2024This dental technique describes a novel cost-effective workflow for integrating mandible kinematics into a static virtual patient. Computed tomography data are segmented...
This dental technique describes a novel cost-effective workflow for integrating mandible kinematics into a static virtual patient. Computed tomography data are segmented and merged with intraoral surface scans and a target tracking video reproducing the mandible movements. A 4-dimensional dynamic virtual patient is created by using an open-source software program, and all patient-specific parameters can be exported for individualization of a virtual or analog articulator.
Topics: Humans; Dental Articulators; Mandible; Movement; Software; Tomography, X-Ray Computed
PubMed: 35304002
DOI: 10.1016/j.prosdent.2022.02.011 -
Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi... Apr 2024This clinical study aimed to assess the trueness of three intraoral scanners for the recor-ding of the maximal intercuspal position (MIP) to provide a reference for...
OBJECTIVES
This clinical study aimed to assess the trueness of three intraoral scanners for the recor-ding of the maximal intercuspal position (MIP) to provide a reference for clinical practice.
METHODS
Ten participants with good occlusal relationship and healthy temporomandibular joint were recruited. For the control group, facebow transferring procedures were performed, and bite registrations at the MIP were used to transfer maxillary and mandibular casts to a mechanical articulator, which were then scanned with a laboratory scanner to obtain digital cast data. For the experimental groups, three intraoral scanners (Trios 3, Carestream 3600, and Aoralscan 3) were used to obtain digital casts of the participants at the MIP following the scanning workflows endorsed by the corresponding manufacturers. Subsequently, measurement points were marked on the control group's digital casts at the central incisors, canines, and first molars, and corresponding distances between these points on the maxillary and mandibular casts were measured to calculate the sum of measured distances (D). Distances between measurement points in the incisor (D), canine (D), and first molar (D) regions were also calculated. The control group's maxillary and mandibular digital casts with the added measurement points were aligned with the experimental group's casts, and D, D, D, and D values of the aligned control casts were determined. Statistical analysis was performed on D, D, D, and D obtained from both the control and experimental groups to evaluate the trueness of the three intraoral scanners for the recording of MIP.
RESULTS
In the control group, D, D, D, and D values were (39.58±6.40), (13.64±3.58), (14.91±2.85), and (11.03±1.56) mm. The Trios 3 group had values of (38.99±6.60), (13.42±3.66), (14.55±2.87), and (11.03±1.69) mm. The Carestream 3600 group showed values of (38.57±6.36), (13.56±3.68), (14.45±2.85), and (10.55±1.41) mm, while the Aoralscan 3 group had values of (38.16±5.69), (13.03±3.54), (14.23±2.59), and (10.90±1.54) mm. Analysis of variance revealed no statistically significant differences between the experimental and control groups for overall deviation D (=0.96), as well as local deviations D (=0.98), D (=0.96), and D (=0.89).
CONCLUSIONS
With standardized scanning protocols, the three intraoral scanners demonstrated comparable trueness to traditional methods in recording MIP, fulfilling clinical requirements.
Topics: Humans; Molar; Incisor; Mandible; Maxilla; Computer-Aided Design; Imaging, Three-Dimensional; Dental Impression Technique
PubMed: 38597082
DOI: 10.7518/hxkq.2024.2023277 -
The Journal of Prosthetic Dentistry May 2024Various techniques have been developed for a 3-dimensional (3D) virtual patient. However, those techniques do not enable the registration of the alignment of the facial...
Various techniques have been developed for a 3-dimensional (3D) virtual patient. However, those techniques do not enable the registration of the alignment of the facial and intraoral digital scans, the registration for the mounting on the virtual articulator, and the integration of the natural head position (NHP) together. In the present manuscript, a scan body system is described that assists with the translation of the horizon orientation within the NHP of the patient into a computer-aided design software program. Additionally, the scan body system facilitates the facial and intraoral alignment, as well as the mounting of the maxillary virtual cast on the virtual articulator. This scan body system facilitates the integration of the 3D virtual patient and reduces chair and laboratory time.
Topics: Humans; Imaging, Three-Dimensional; Computer-Aided Design; Head; User-Computer Interface; Software; Posture; Dental Articulators; Virtual Reality
PubMed: 35672165
DOI: 10.1016/j.prosdent.2022.04.016 -
International Journal of Computerized... Jun 2024There is an ongoing debate about the benefits of the facebow and individual articulator settings in prosthodontics when compared with simpler methods. The present study...
AIM
There is an ongoing debate about the benefits of the facebow and individual articulator settings in prosthodontics when compared with simpler methods. The present study aims to determine whether the implementation of novel algorithmic articulator concepts may be an alternative to avoid dynamic interference contacts during the design process of fixed posterior restorations, and to what extent the occlusal morphology of the restoration is affected.
MATERIALS AND METHODS
From a chairside CAD database, a total of 50 clinical patient cases documenting 61 planned fixed restorations in the posterior tooth region were selected. A common CAD software program was used for the automated knowledge-based design process. When designing the restorations, functional concepts were applied, including the pure static occlusion, the average articulation, three different articulator settings as a control, and a combination of a broad range of articulation parameters (the full range dynamic articulation). The resulting dynamic contact points were compared both visually and metrically with a monitoring software program.
RESULTS
There is a highly significant difference in avoiding dynamic interference contacts when applying the full range dynamic articulation compared with the pure static occlusion (P < 0.001) and the average articulation (P < 0.001). Furthermore, the superimposition revealed that the surface of the restorations showed nearly no visual morphologic changes after virtually grinding-in the interpenetrating contact points.
CONCLUSION
The full range dynamic articulation can be used for the design of small fixed posterior restorations to avoid most dynamic interference contacts without the need for determining individual parameters for each patient.
Topics: Humans; Algorithms; Dental Prosthesis Design; Computer-Aided Design; Dental Occlusion; Dental Restoration, Permanent; Software; Dental Articulators
PubMed: 37823544
DOI: 10.3290/j.ijcd.b4494379 -
The Journal of Prosthetic Dentistry May 2024Different techniques of transferring the maxillary cast into the analog semi-adjustable articulator by using the true horizontal or gravity reference plane have been...
Different techniques of transferring the maxillary cast into the analog semi-adjustable articulator by using the true horizontal or gravity reference plane have been reported. However, procedures are required for recording this reference plane and transferring the maxillary cast into the virtual semi-adjustable articulator. In the present manuscript, a technique is described for registering the true horizontal or gravity plane in relationship to the natural head position of the patient by using an optical jaw tracking system. Additionally, the recorded true horizontal plane is used to transfer the maxillary cast into the virtual semi-adjustable articulator by using a dental computer-aided design program. This technique facilitates the maxillary cast transfer into the virtual articulator by using the true horizontal plane recorded with an optical jaw tracking system, maximizing the functionality of the optical jaw tracking device.
PubMed: 38714458
DOI: 10.1016/j.prosdent.2024.03.049 -
The Journal of Prosthetic Dentistry Feb 2024This technique uses 3 or 4 two-dimensional (2D) photographs, including a frontal headshot with a facebow and lip retractors, a profile headshot with a facebow and lip...
This technique uses 3 or 4 two-dimensional (2D) photographs, including a frontal headshot with a facebow and lip retractors, a profile headshot with a facebow and lip retractors on the right or left side, and a frontal headshot with a facebow during maximum smile without retractors. These 2D photographs are used to digitally mount casts on a virtual articulator.
PubMed: 38418301
DOI: 10.1016/j.prosdent.2024.01.032 -
Journal of Dentistry Aug 2023The aim of this study was to clinically evaluate the accuracy of a digital axiographic recording system in tracing the sagittal condylar inclination.
OBJECTIVES
The aim of this study was to clinically evaluate the accuracy of a digital axiographic recording system in tracing the sagittal condylar inclination.
METHODS
An axiographic examination that records the sagittal condylar path during protrusive/retrusive movement was performed on ten patients. Each subject was registered five different times by two different systems: 1) the Cadiax Gamma Diagnostic 4 computerized system as the control; 2) the Zebris Jaw Motion Analyser+ Optic System as the tested digital axiographic recording system. The records obtained allow to calculate the kinematic terminal transverse horizontal axis and the sagittal condylar inclination (SCI) at 3 and 5 mm along the pro-retrusive path. A linear mixed model was used to analyze if there was a statistically significant difference between the two systems.
RESULTS
The mean left SCI value recorded by Zebris system were 49.81 ± 10.64° at 3 mm, 48.10 ± 11.04° at 5 mm, while the values recorded by Gamma system were 55.16° at 3 mm, 52.18° at 5 mm. The mean right SCI value recorded by Zebris system were 54.53 ± 10.26° at 3 mm, 51.85 ± 8.55° at 5 mm, while the values recorded by Gamma system were 49.68° at 3 mm, 48.23° at 5 mm. Linear mixed model showed no significant statistical difference between the two systems.
CONCLUSIONS
Based on preliminary results, the Zebris Jaw Motion Analyzer+ Optic System demonstrates comparable accuracy to the Cadiax Gamma Diagnostic 4 when measuring sagittal condylar inclination.
CLINICAL SIGNIFICANCE
The digital axiographic recording system enables to evaluate sagittal condylar inclination and to adjust virtual articulators in a digital workflow.
Topics: Humans; Mandibular Condyle; Jaw Relation Record; Movement; Dental Articulators; Biomechanical Phenomena
PubMed: 37331577
DOI: 10.1016/j.jdent.2023.104583 -
Journal of Pharmacy & Bioallied Sciences Feb 2024The transfer of interocclusal data from the patient's mouth to articulators utilizing various types of recording media is necessary for the production of dental...
UNLABELLED
The transfer of interocclusal data from the patient's mouth to articulators utilizing various types of recording media is necessary for the production of dental prostheses. Occlusal errors in the final prosthesis result from any discrepancies in these interocclusal records.
MATERIALS AND METHODS
The purpose of this study was to assess the linear dimensional changes in the four elastomeric interocclusal recording materials as well as the material's resistance to compression during the cast mounting on the articulator.
RESULT
All four elastomeric materials showed decreasing stability over time and 2 mm thickness showed the highest compression resistance with minimal articulation error.
CONCLUSION
Dimensional stability depends on material and time factors, and compressive resistance decreases with increasing thickness.
PubMed: 38595621
DOI: 10.4103/jpbs.jpbs_1047_23 -
The Journal of Prosthetic Dentistry Jan 2024Jaw tracking systems can record mandibular movement such as the repeatable reference position and excursive movements of the mandible. A technique for integrating the...
Integrating the repeatable reference position and excursive movements of the mandible acquired using a jaw tracker into the design procedures of an occlusal device: A technique.
Jaw tracking systems can record mandibular movement such as the repeatable reference position and excursive movements of the mandible. A technique for integrating the recorded repeatable reference position of the mandible and excursive movements captured using an optical jaw tracking system into the design procedures of an occlusal device is described. The mandibular motion of the patient is directly used to design the occlusal device, replacing the virtual articulator. The described technique aims to reduce the delivery time by incorporating the recorded motion of the patient into the virtual design of the occlusal device.
PubMed: 38238212
DOI: 10.1016/j.prosdent.2023.12.011