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The European Journal of Prosthodontics... Mar 2023To determine whether the use of single or combined mechanical and virtual articulators, as well as facebows, jaw motion trackers, face scanners, and related devices,...
AIMS
To determine whether the use of single or combined mechanical and virtual articulators, as well as facebows, jaw motion trackers, face scanners, and related devices, actually improve the efficacy of the prosthesis obtained in terms of lifespan and patient-related outcomes. To coin the terms Analogic and Digital Virtual Patients (AVP and DVP) as an attempt to analyze, clarify and synthesize terminology and workflows related to previously so-called devices.
MATERIALS AND METHODS
A scoping review was accomplished involving different databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA-ScR) checklist and JBI guidance were followed to extract data regarding the Population, Context and Concept established.
RESULTS
Available literature on the efficacy of using devices and techniques related to both AVP and DVP workflows showed arguable study designs, great heterogeneity, and questionable quality.
CONCLUSIONS
The terms AVP and DVP have been coined as a first step to clarify and simplify concepts and workflows related to the use of both mechanical and virtual articulators, as well as facebows, or facial and intraoral scanners, among others. This scoping review cannot claim that an AVP approach leads to more effective and efficient prosthetic restorations.
PubMed: 36927617
DOI: 10.1922/EJPRD_2485Pradies17 -
BMC Oral Health Mar 2023Precise occlusal design of implant-supported fixed prostheses is difficult to achieve by the conventional wax-up method, often requiring chairside adjustments. The...
BACKGROUND
Precise occlusal design of implant-supported fixed prostheses is difficult to achieve by the conventional wax-up method, often requiring chairside adjustments. The computer-aided design (CAD) method is promising. This study aims to compare the occlusal contacts and clearance of posterior implant-supported single crowns designed by the CAD and conventional methods.
METHODS
Sample size calculation indicated fourteen samples per group. Two sets of type-IV plaster casts with a single implant analog inserted in the posterior teeth region were mounted as master casts in a mechanical articulator in maximal intercuspal position (MIP). Seven working cast sets were obtained from each master cast by a closed tray technique, and mounted in MIP. Two implant-supported single crowns were designed with an occlusal clearance to achieve light occlusal contact in each working cast set by CAD and conventional method, separately. For the CAD group, the crown was designed in digital models obtained by scanning the working casts. For the conventional group, wax-up of the crown was prepared on the working casts and scanned to generate a STL file. In the working and master casts, mean and minimum occlusal clearances in the designed occlusal contact area of the both finished prostheses were calculated using the occlusal clearance (OC) and occlusal record (OR) method. The prostheses' occlusion was evaluated in master casts.
RESULTS
For the evaluation in the working casts, both design methods had similar mean occlusal clearances by the OC method (195.4 ± 43.8 vs. 179.8 ± 41.8 μm; P = 0.300), while CAD group resulted in a significantly larger minimum occlusal clearance in the designed occlusal contact area (139.5 ± 52.3 vs. 99.8 ± 43.8 μm; P = 0.043). Both design methods had similar mean and minimum occlusal clearances by the OR method (P > 0.05). For the evaluation in the master casts, both design techniques had similar mean and minimum occlusal clearances, number and distribution of occlusal contacts, and lateral interference ratios (P > 0.05).
CONCLUSION
Occlusal contact and clearance of posterior implant-supported single crowns designed by the CAD method can be at least as good as those designed by the conventional wax-up method.
Topics: Humans; Crowns; Computer-Aided Design; Dental Occlusion; Research Design; Dental Impression Technique; Dental Prosthesis Design
PubMed: 36918877
DOI: 10.1186/s12903-023-02847-w -
The Journal of Advanced Prosthodontics Feb 2023To compare the sagittal condylar inclination (SCI) in dentate individuals measured by the different methods with mechanical articulator (MA), virtual articulator (VA),...
PURPOSE
To compare the sagittal condylar inclination (SCI) in dentate individuals measured by the different methods with mechanical articulator (MA), virtual articulator (VA), and a jaw tracking device (JTD) system.
MATERIALS AND METHODS
A total of 22 healthy dentate participants were enrolled in this study. For MA workflow, the SCI was obtained by a semi-adjustable articulator with protrusive interocclusal records. The SCI was also set on a VA by aligning intraoral scan (IOS) with cone beam computed tomography (CBCT) and facial scan (FS), respectively. These virtual workflows were conducted in a dental design software, namely VA and VA. Meanwhile, a JTD system was also utilized to perform the measurement. Intraclass correlation was used to assess the repeatability within workflows. The bilateral SCI values were compared by Wilcoxon matched-pairs signed rank test for each workflow, and Kruskal-Wallis test and post hoc p-value Bonferroni correction were used to compare the differences among four workflows. The agreement of VA, VA, and JTD compared with MA was evaluated by Bland-Altman analysis.
RESULTS
Intraclass correlation of the SCI revealed a high degree of repeatability for each workflow. There were no significant differences between the left and right sides ( > .05), except for VA ( = .028). Significant differences were not found between MA and VA ( > .05). Bland-Altman plots indicated VA, VA, and JTD were considered to substitute MA with high 95% limits of agreement.
CONCLUSION
The workflow of VA provided an alternative approach to measure the SCI compared with MA.
PubMed: 36908753
DOI: 10.4047/jap.2023.15.1.11 -
Journal of Dentistry May 2023To measure the accuracy (trueness and precision) of the maxillomandibular relationship at centric relation position recorded by using 3 different intraoral scanners with...
Accuracy of the maxillomandibular relationship at centric relation position recorded by using 3 different intraoral scanners with or without an optical jaw tracking system: An in vivo pilot study.
PURPOSE
To measure the accuracy (trueness and precision) of the maxillomandibular relationship at centric relation position recorded by using 3 different intraoral scanners with or without an optical jaw tracking system.
MATERIAL AND METHODS
A completely dentate volunteer was selected. Seven groups were generated: conventional procedure (control group), 3 IOSs: Trios4 (Trios4 group), Itero Element 5D Plus (Itero group), i700 (i700 group), and 3 groups with a jaw tracking system for each corresponding IOS system (Modjaw-Trios4, Modjaw-iTero, and Modjaw-i700 groups) (n = 10). In the control group, casts were mounted on an articulator (Panadent) using a face bow and a CR record captured with the Kois deprogrammer (KD). The casts were digitized by using a scanner (T710) (control files). In the Trios4 group, intraoral scans were obtained by using the corresponding IOS and duplicated 10 times. The KD was used to obtain a bilateral occlusal record at CR position. These same procedures were followed for the Itero and i700 groups. In the Modjaw-Trios 4 group, the intraoral scans acquired by using the corresponding IOS at MIP were imported into the jaw tracking program. The KD was used to record the CR relationship. For acquiring the specimens in the Modjaw-Itero and Modjaw-i700 groups, the same procedures were followed as in the Modjaw-Trios4 group, with the scans obtained with the Itero and i700 scanners respectively. The articulated virtual casts of each group were exported. Thirty-six inter-landmark linear measurements were used to calculate the discrepancies between the control and experimental scans. The data were analyzed by using 2-way ANOVA followed the pairwise comparison Tukey tests (α=0.05).
RESULTS
Significant trueness and precision discrepancies were found among the groups tested (P<.001). The Modjaw-i700, Modjaw-iTero, Modjaw-Trios4, and i700 groups obtained the best trueness and precision among the groups tested, and the iTero and Trios4 groups obtained the worst trueness. The iTero group obtained the worst precision among the groups tested (P>.05).
CONCLUSIONS
The maxillomandibular relationship recorded was influenced by the technique selected. Except for the i700 IOS system, the optical jaw tracking system tested improved the trueness value of the maxillomandibular relationship recorded at CR position when compared with the corresponding IOS.
Topics: Humans; Imaging, Three-Dimensional; Pilot Projects; Centric Relation; Dental Impression Technique; Computer-Aided Design; Models, Dental
PubMed: 36889536
DOI: 10.1016/j.jdent.2023.104478 -
The Journal of Prosthetic Dentistry Mar 2023Establishing new dentition and occlusal schemes requires a thorough understanding of the principles of occlusion, mandibular movements, phonetics, and esthetics. This...
Establishing new dentition and occlusal schemes requires a thorough understanding of the principles of occlusion, mandibular movements, phonetics, and esthetics. This presentation is designed to help understand the dynamics of mandibular movements, form and function of the dentition, occlusal schemes, patient simulation, and the interaction of those factors on occlusal rehabilitation. Special emphasis is laid upon articulator design and the current innovations utilizing digital technology in the development of this instrument from an articulator to a patient simulator.
Topics: Humans; Dental Articulators; Esthetics, Dental; Dental Care; Dental Occlusion; Mandible
PubMed: 36870756
DOI: 10.1016/j.prosdent.2023.01.015 -
Life (Basel, Switzerland) Jan 2023A complex prosthodontic treatment is believed to be more successful when the condylar path is replicated using the articulator. However, there is an ongoing major...
Complicated Relationships between Anterior and Condylar Guidance and Their Clinical Implications-Comparison by Cone Beam Computed Tomography and Electronic Axiography-An Observational Cohort Cross-Sectional Study.
A complex prosthodontic treatment is believed to be more successful when the condylar path is replicated using the articulator. However, there is an ongoing major disagreement between the researchers as the exact relationship between the posterior and anterior determinants has not been clear. The purpose of this study was to investigate whether the protrusive movement of the mandible does correlate with the temporomandibular joint (TMJ) anatomy or with incised features. Subjects (15 males and 15 females) were qualified for this study based on an initial interview including the following criteria: age 21-23 (+/-1), no history of trauma, orthodontic treatment, or temporomandibular disorders (TMD). For each patient, the angle of the condylar path, incisal guidance angle (IGA), interincisal angle, as well as overbite and overjet were measured on cone beam computed tomography (CBCT). This was followed by the examination with the Modjaw electronic axiograph recording and calculating the functional sagittal condylar guidance angle (SCGA) for the right and left TMJ during the protrusion. The results show that the mean functional axiographic measurement of SCGA in protrusion significantly correlates with the TMJ anatomy presented on CBCT. Moreover, a significant correlation was found between the values of SCGA in the functional and anatomical measurements in all its variants. It turned out that, statistically, the AB measurement was the most accurate. Finally, results showed that incisal relationships of permanent teeth such as overbite, overjet, incisal guidance angle and interincisal angle do not correlate with TMJ anatomy, and therefore, regarding an analyzed study group, do not affect the TMJ formation in young adults.
PubMed: 36836692
DOI: 10.3390/life13020335 -
The Journal of Prosthetic Dentistry Feb 2023Alternatives to the bilateral interocclusal registration scanning technique to improve virtual articulation have not been fully investigated.
STATEMENT OF PROBLEM
Alternatives to the bilateral interocclusal registration scanning technique to improve virtual articulation have not been fully investigated.
PURPOSE
The purpose of this in vitro study was to compare the accuracy of virtually articulating digital casts by using bilateral interocclusal registration scans versus a complete arch interocclusal scan.
MATERIAL AND METHODS
A set of maxillary and mandibular reference casts were hand-articulated and mounted on an articulator. The mounted reference casts were scanned, and the maxillomandibular relationship record was scanned 15 times using 2 different scanning techniques, the bilateral interocclusal registration scan (BIRS) and complete arch interocclusal registration scan (CIRS), with an intraoral scanner. The generated files were transferred to a virtual articulator, and each set of scanned casts was articulated using BIRS and CIRS. The virtually articulated casts were saved as a set and transferred to a 3-dimensional (3D) analysis program. The scanned casts were set in the same coordinate system as the reference cast and overlaid on top of the reference cast for analysis. Two anterior and 2 posterior points were selected to determine points of comparison between the reference cast and test casts virtually articulated with BIRS and CIRS. The mean discrepancy between the 2 test groups and the anterior and posterior mean discrepancy within each group were tested for significance by using the Mann-Whitney U test (α=.05).
RESULTS
A significant difference was found between the virtual articulation accuracy of BIRS and CIRS (P<.001). The mean deviation for BIRS was 0.053 ±0.051 mm and that for CIRS was 0.265 ±0.241 mm. Furthermore, significant differences were found between the anterior and posterior deviations in both BIRS (P=.020) and CIRS (P<.001). The mean deviation for BIRS was 0.034 ±0.026 mm in the anterior and 0.073 ±0.062 mm in the posterior. The mean deviation for CIRS was 0.146 ±0.108 mm anteriorly and 0.385 ±0.277 mm posteriorly.
CONCLUSIONS
BIRS was more accurate than CIRS for virtual articulation. Moreover, the alignment accuracy of anterior and posterior sites for both BIRS and CIRS exhibited significant differences, with the anterior alignment exhibiting better accuracy in relation to the reference cast.
PubMed: 36813588
DOI: 10.1016/j.prosdent.2023.01.028 -
The Journal of Advanced Prosthodontics Dec 2022The purpose of this study was to assess whether scanning strategies of virtual interocclusal record (VIR) affect the accuracy of VIR during intraoral scanning.
PURPOSE
The purpose of this study was to assess whether scanning strategies of virtual interocclusal record (VIR) affect the accuracy of VIR during intraoral scanning.
MATERIALS AND METHODS
Five pairs of reference cubes were added to the digital upper and lower dentitions of a volunteer, which were printed into resin casts. Subsequently, the resin casts were articulated in the maximal intercuspal position in a mechanical articulator and scanned with an industrial computed tomography system, of which the VIR was served as a reference VIR. The investigated VIR of the upper and lower jaws of the resin master cast were recorded with an intraoral scanner according to 9 designed scanning strategies. Then, the deviation between the investigated VIRs and reference VIR were analyzed, which were measured by the deviation of the distances of six selected reference points on the upper reference cubes in each digital cast to the XY-plane between the investigated VIRs and reference VIR.
RESULTS
For the deviation in the right posterior dentitions, RP group (only scanning of right posterior dentitions) showed the smallest deviation. Besides, BP group (scanning of bilateral posterior dentitions) showed the smallest deviation in the left posterior dentitions. Moreover, LP group (scanning of left posterior dentitions) showed the smallest deviation in the anterior dentitions. For the deviation of full dental arches, BP group showed the smallest deviation.
CONCLUSION
Different scanning strategies of VIR can influence the accuracy of alignment of virtual dental casts. Appropriate scanning strategies of VIR should be selected for different regions of interest and edentulous situations.
PubMed: 36685791
DOI: 10.4047/jap.2022.14.6.369 -
The Journal of Prosthetic Dentistry Jan 2023Digital systems including intraoral scanners (IOSs) and optical jaw tracking systems can be used to acquire the maxillomandibular relationship at the centric relation...
Differences in maxillomandibular relationship recorded at centric relation when using a conventional method, four intraoral scanners, and a jaw tracking system: A clinical study.
STATEMENT OF PROBLEM
Digital systems including intraoral scanners (IOSs) and optical jaw tracking systems can be used to acquire the maxillomandibular relationship at the centric relation (CR). However, the discrepancy of the maxillomandibular relationship recorded at the CR position when using digital methods remains uncertain.
PURPOSE
The purpose of this clinical study was to compare the accuracy of the maxillomandibular relationship recorded at the CR position using a conventional procedure, 4 different IOSs, and an optical jaw tracking system.
MATERIAL AND METHODS
A completely dentate volunteer was selected. A Kois deprogrammer (KD) was fabricated. Six groups were created based on the technique used to obtain diagnostic casts and record the maxillomandibular relationship at the CR position: conventional procedures (CNV group), 4 IOS groups: TRIOS4 (TRIOS4 group), iTero Element 5D (iTero group), i700 wireless (i700 group), Primescan (Primescan group), and a jaw tracking system (Modjaw) (Modjaw group) (n=10). In the CNV group, conventional diagnostic stone casts were obtained. A facebow record was used to mount the maxillary cast on an articulator (Panadent). The KD was used to obtain a CR record for mounting the mandibular cast, and the mounted casts were digitized by using a scanner (T710) to acquire the reference scans. In the TRIOS group, intraoral scans were obtained and duplicated 10 times. The KD was used to obtain a bilateral virtual occlusal record at the CR position. To acquire the specimens of the iTero, i700, and Primescan groups, the procedures in the TRIOS4 group were followed, but with the corresponding IOS. In the Modjaw group, the KD was used to record and export the maxillomandibular relationship at the CR position. Articulated virtual casts of each group were exported. Thirty-six interlandmark linear measurements were computed on both the reference and experimental scans. The distances obtained on the reference scan were used to calculate the discrepancies with the distances obtained on each experimental scan. The data were analyzed by using 1-way ANOVA followed by the pairwise comparison Tukey tests (α=.05).
RESULTS
The trueness and precision of the maxillomandibular relationship record were significantly affected by the technique used (P<.001). The maxillomandibular relationship trueness values from high to low were iTero (0.14 ±0.09 mm), followed by the Modjaw (0.20 ±0.04 mm) and the TRIOS4 (0.22 ±0.09 mm) groups. However, the iTero, Modjaw, and TRIOS4 groups were not significantly different from each other (P>.05). The i700 group obtained the lowest trueness and precision values (0.40 ±0.22 mm) of all groups tested, followed by the Primescan grop (0.26±0.13 mm); however, the i700 and Primescan groups had significantly lower trueness and precision than only the iTero group (P<.05).
CONCLUSIONS
The trueness and precision of the maxillomandibular relationship recorded at the CR position were influenced by the different digital techniques tested.
PubMed: 36682896
DOI: 10.1016/j.prosdent.2022.12.007 -
Journal of Clinical Medicine Jan 2023Available knowledge about malocclusion and cephalometric variables and their connection with an increased risk of condylar displacement (CD) is scarce. This article aims... (Review)
Review
The Role of Maxillofacial Structure and Malocclusion on Condylar Displacement in Maximum Intercuspation and Centric Relation in Patients Seeking Orthodontic Treatment-A Scoping Review.
BACKGROUND
Available knowledge about malocclusion and cephalometric variables and their connection with an increased risk of condylar displacement (CD) is scarce. This article aims to present current information on the relationship between centric relation-maximum intercuspal position discrepancies and maxillofacial morphology and malocclusion in patients seeking orthodontic treatment as well as to identify those who require expanded diagnostic evaluation for this disorder.
METHODS
This review analyzed the PubMed, Cochrane Library, Web of Science, and Scopus electronic databases up to February 2022. Keywords and additional manual searches were performed. Literature selection was based the PRISMA-ScR checklist. The JBI Critical Appraisal Tool assessed the methodological quality of included studies.
RESULTS
The databases search provided 2321 studies. A total of 10 studies were included in this review after eligibility criteria and JBI assessment. This review was separated into five parts that evaluated CD correlations depending on the following: maxillofacial structure in different vertical and sagittal skeletal patterns, vertical, horizontal, and transverse malocclusions.
CONCLUSIONS
A hyperdivergent facial skeletal structure is a risk factor for increased CD, particularly in the vertical dimension. The condylar processes are usually displaced in a posteroinferior direction. Further studies are warranted to elucidate the relationship among remaining skeletal and dental malocclusions and the occurrence of CD.
PubMed: 36675620
DOI: 10.3390/jcm12020689