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Life (Basel, Switzerland) Jun 2023The condylar guidance value (CGV) measurement constitutes an important part of a holistic prosthodontic treatment plan, with horizontal CGVs (HCGVs) and lateral CGVs... (Review)
Review
The condylar guidance value (CGV) measurement constitutes an important part of a holistic prosthodontic treatment plan, with horizontal CGVs (HCGVs) and lateral CGVs (LCGVs) being two of the most prominently recognized. This systematic review aimed at evaluating the efficacy of two different types of CGV measurement protocols-articulators (both arcon and non-arcon) and panoramic radiographs. Additionally, it attempts to determine which of the mentioned methods performs better across several parameters. Several important web databases were searched using search terms derived from medical subject headings (MeSH), using keywords linked to "Arcon articulator", "Condylar guidance angle", "non-arcon articulator", "Panoramic x-ray" and "Radiographic examination", which constituted the first step in the study selection strategy. After completion, the search strategy which initially turned up to 831 papers, eventually ended up with 13 studies. The review and subsequent meta-analysis revealed that panoramic radiographs had noticeably greater efficacy in terms of the CGVs as compared to the articulators in the majority of the studies. Within the articulators, the arcon types recorded slightly higher CGVs than the non-arcon variety owing to the precision of jaw movement simulation in the former. However, further studies are required to validate these findings and establish more precise guidelines for the use of CGV measurement protocols in prosthodontic practice.
PubMed: 37374135
DOI: 10.3390/life13061352 -
Healthcare (Basel, Switzerland) Jun 2022The clinical remount procedure, which involves remounting the dentures on an articulator with interocclusal records, can effectively reduce occlusal discrepancies. This... (Review)
Review
The clinical remount procedure, which involves remounting the dentures on an articulator with interocclusal records, can effectively reduce occlusal discrepancies. This procedure can be applied not only to new dentures but also to those already in service; however, research in this field is still scarce. This narrative review aims to establish a hypothetical mechanism and possible indications and contraindications for this technique as a basis for further research. Current studies have revealed a high prevalence of malocclusion in delivered dentures. Performing a clinical remount on these existing dentures would enhance the oral function of the denture wearer and would enable effective and accurate correction of the accumulated errors in the jaw relationship in a stable working environment. This technique should be performed if a patient has poor masticatory function or occlusion-related complaints. However, performing a clinical remount on dentures with an excessive anterior-posterior discrepancy between the centric relation and the maximal intercuspal position or on dentures with extremely low occlusal vertical dimension, is considered less effective. The clinical remount procedure remains an essential skill both for fabricating quality dentures and maintaining those already in service.
PubMed: 35742118
DOI: 10.3390/healthcare10061067 -
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 -
Journal of Dentistry Oct 2023A digital workflow for implant-supported fixed complete prostheses (ISFCP) using photogrammetry (PG), virtual articulator (VA), and virtual facebow (VF) data remains a...
BACKGROUND
A digital workflow for implant-supported fixed complete prostheses (ISFCP) using photogrammetry (PG), virtual articulator (VA), and virtual facebow (VF) data remains a challenge.
METHODS
The novel ISFCP technique included four steps: (1) formation of a dynamic virtual patient, (2) integration of PG data, (3) fabrication of a diagnostic ISFCP, and (4) fabrication of a definitive ISFCP and test of the deviation.
RESULTS
Dynamic virtual patients were formed by integrating PG, VA, and VF data. The cumulative root mean square deviation between the designed data and actual definitive prosthesis was 140.4 µm.
CONCLUSIONS
The novel technique for ISFCP fabrication described in this paper can help optimise the clinical efficiency and quality of ISFCP but requires an initial learning curve.
CLINICAL SIGNIFICANCE
This technique provides a direct workflow, using PG, VA, and VF data, to fabricate ISFCP based on the provisional restoration.
Topics: Humans; Dental Prosthesis Design; Dental Implants; Dental Prosthesis, Implant-Supported; Workflow; Computer-Aided Design
PubMed: 37574104
DOI: 10.1016/j.jdent.2023.104649 -
Journal of Prosthodontics : Official... Dec 2022With the widespread application of digital impression techniques in prosthetic dentistry, accurate intraoral scan mounting, and virtual articulator parameters setting as...
An Indirect Digital Technique to Transfer 3D Printed Casts to a Mechanical Articulator With Individual Sagittal Condylar Inclination Settings Using CBCT and Intraoral Scans.
With the widespread application of digital impression techniques in prosthetic dentistry, accurate intraoral scan mounting, and virtual articulator parameters setting as per patients' anatomic structures are essential for treatment planning and restoration fabrication, especially for complex rehabilitation cases; meanwhile, marginal fit checking, occlusal adjustment, and porcelain layering of restorations are also crucial procedures in all cases in which the analog procedure to mount maxillary arches on a mechanical articulator is still required. This technique article presents an indirect digital approach that can first achieve virtual intraoral scan mounting and sagittal condylar inclination value setting of an Artex virtual articulator based on bony structures provided by a single cone beam computed tomography scan. It then facilitates the transfer of virtually mounted intraoral scans from the virtual articulator to the matched Artex mechanical articulator by relating a digitally scanned mounting plate of the Artex mechanical articulator to the virtual articulator, printing the intraoral scan and mounting plate scan assembly, and then mounting the printed casts on the mechanical articulator based on the printed mounting plate. This technique eliminates the conventional facebow transfer and protrusive bite registration procedures and offers a straightforward approach for the seamless integration of virtual environments and analog workflows into clinical practice. It aids in the design of restorations that are harmonious with the mandibular movements and reduces chairside adjustment time.
Topics: Humans; Jaw Relation Record; Dental Articulators; Spiral Cone-Beam Computed Tomography; Printing, Three-Dimensional
PubMed: 35864801
DOI: 10.1111/jopr.13570 -
Shanghai Kou Qiang Yi Xue = Shanghai... Feb 2021Judged from the clinical manifestations, etiological mechanisms and jaw morphological structures, malocclusions with mandibular deviation and facial asymmetry are...
Judged from the clinical manifestations, etiological mechanisms and jaw morphological structures, malocclusions with mandibular deviation and facial asymmetry are classified into three main categories, i.e., those with mandibular positioning factors, those with mandibular condyle defects, and those with jaw congenital deformities. In the first category, three subtypes, including mandibular rotation caused by dentitional irregularities, by dental compensation and by habitual posturing, are further defined. In the second category, mandibular deviation caused by condylar asymmetrical resorption or hyperplasia are defined as the two subtypes. The third category is further divided into two subtypes, i.e., jaw and facial asymmetry resulting from maxillary or mandibular structural deformities. The prime goal of orthodontic therapy is to displace and restore the deviated mandible to its right position, followed by correction of occlusal intercuspation. As an important procedure of the whole treatment protocol, It is critical to detect and localize the correct mandibular position by manipulation and then register it by wax pattern and articulator transferring. For the cases with mandibular functional elements and condylar asymmetrical length, the treatment modalities include orthopedic repositioning of the mandible by using occlusal and bite plane, SGTB and SGHB therapies; for cases with growth and developmental anomalies, orthognathic intervention should be an optimal solution.
Topics: Dental Occlusion; Facial Asymmetry; Humans; Malocclusion; Mandible; Mandibular Condyle
PubMed: 33907770
DOI: No ID Found -
The British Journal of Oral &... Oct 2020The 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... (Randomized Controlled Trial)
Randomized Controlled Trial
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.
Topics: Dental Articulators; Follow-Up Studies; Humans; Imaging, Three-Dimensional; Occlusal Splints; Orthognathic Surgical Procedures; Patient Care Planning; Surgery, Computer-Assisted
PubMed: 32446591
DOI: 10.1016/j.bjoms.2020.04.032 -
BMC Oral Health Oct 2020Fully adjustable articulators and pantographs record and reproduce individual mandibular movements. Although these instruments are accurate, they are operator-dependant...
BACKGROUND
Fully adjustable articulators and pantographs record and reproduce individual mandibular movements. Although these instruments are accurate, they are operator-dependant and time-consuming. Pantographic recording is affected by inter and intra operator variability in the individuation of clinical reference points and afterwards in reading pantographic recording themselves. Finally only border movements can be reproduced.
METHODS
Bionic Jaw Motion system is based on two components: a jaw movement analyzer and a robotic device that accurately reproduces recorded movements. The jaw movement analyzer uses an optoelectronic motion system technology made of a high frequency filming camera that acquires 140frames per second and a custom designed software that recognizes and determines the relative distance at each point in time of markers with known geometries connected to each jaw. Circumferential modified retainers connect markers and do not cover any occlusal surfaces neither obstruct occlusion. The recording process takes 5 to 10 s. Mandibular movement performance requires six degrees of freedom of movement, 3 rotations and 3 translations. Other robots are based on the so-called delta mechanics that use several parallel effectors to perform desired movements in order to decompose a complex trajectory into multiple more simple linear movements. However, each parallel effector introduces mechanical inter-component tolerances and mathematical transformations that are required to transform a recorded movement into the combination of movements to be performed by each effector. Bionic Jaw Motion Robot works differently, owing to three motors that perform translational movements and three other motors that perform rotations as a gyroscope. This configuration requires less mechanical components thus reducing mechanical tolerances and production costs. Both the jaw movement analyzer and the robot quantify the movement of the mandible as a rigid body with six degrees of freedom. This represents an additional advantage as no mathematical transformation is needed for the robot to reproduce recorded movements.
RESULTS
Based on the described procedure, Bionic Jaw Motion provide accurate recording and reproduction of maxillomandibular relation in static and dynamic conditions.
CONCLUSION
This robotic system represents an important advancement compared to available analogical and digital alternatives both in clinical and research contexts for cost reduction, precision and time saving opportunities.
Topics: Dental Articulators; Jaw Relation Record; Mandible; Movement; Reproduction; Robotics
PubMed: 33028288
DOI: 10.1186/s12903-020-01257-6 -
Dental Research Journal 2023Horizontal condylar guidance (HCG) is registered by protrusive interocclusal records but in nonarcon articulators, these records can affect the accuracy. The present...
BACKGROUND
Horizontal condylar guidance (HCG) is registered by protrusive interocclusal records but in nonarcon articulators, these records can affect the accuracy. The present study aimed to evaluate the effect of a novel rotation coordinating device (RCD) on condylar guidance setting with protrusive interocclusal records.
MATERIALS AND METHODS
The study was designed as a comparative investigation. Stone maxillary and mandibular casts were mounted on a fully adjustable instrument as the patient. Duplicate casts were mounted on an arcon and a nonarcon articulator with corresponding face bow records and in maximum intercuspation relation. Five different condylar guidance inclinations for both sides (20°, 30°, 40°, 50°, and 60°) were set on the fully adjustable instrument and 16 protrusive interocclusal records were established at each setting. HCG was set for arcon, nonarcon articulators, and nonarcon articulators with RCD. Data were analyzed using one-sample -test to compare with actual HCG and one-way analysis of variance ( =0.05).
RESULTS
Mean HCG for studied articulators was 35.40 for arcon, 30.31 for nonarcon without RCD, and 35.61 for nonarcon with RCD which were significantly different from actual HCG ( < 0.05). HCG of the nonarcon with RCD showed no significant difference with arcon articulator ( = 0.71) while both were significantly different from nonarcon without RCD ( < 0.001).
CONCLUSION
"The RCD" compensates the condylar guidance inclination difference between arcon and nonarcon articulators. The device precisely transfers the hinge movement of the upper member of the articulator to the condylar track.
PubMed: 38020259
DOI: No ID Found -
The Journal of Prosthetic Dentistry Aug 2023The volume of occlusal adjustment of digital occlusal devices designed with different digital occlusal articulators is unknown.
Comparative evaluation of the volume of occlusal adjustment of repositioning occlusal devices designed by using an average value digital articulator and the jaw movement analyzer.
STATEMENT OF PROBLEM
The volume of occlusal adjustment of digital occlusal devices designed with different digital occlusal articulators is unknown.
PURPOSE
The purpose of this clinical study was to evaluate and compare the clinical efficacy and volume of occlusal adjustment of digital occlusal devices designed by using an average value digital articulator and the jaw movement analyzer (JMA).
MATERIAL AND METHODS
Thirty participants were randomly divided into 2 groups, an Average value group and a JMA group, with 15 participants in each group. The centric relation position of the participants was determined by an experienced investigator with the aid of a leaf gauge. An intraoral scanner (TRIOS 3) was used to obtain digital scans of the maxillary and mandibular dentition and the maxillomandibular relationship record in the centric relation position. Personalized articulator parameters of participants in the JMA group were obtained by using a JMA (JMAnalyser). Different articulator parameters were used to fabricate an occlusal device in a denture design software program (exocad DentalCAD). The surface of the occlusal device was coated with a dental optical spray and then scanned by using a laboratory scanner (Kavo LS3). The process was repeated after the occlusal device was adjusted. The files of the 2 scans were imported into a reverse engineering software program, and the root mean square (RMS) values were obtained by best-fit alignment and 3-dimensional comparison. The Shapiro-Wilk normality test and homogeneity of variance test were performed, and t tests were used to evaluate differences in the RMS values between the groups (α=.05).
RESULTS
The experimental data were generally normally distributed (P>.05). No statistically significant difference was found between the RMS values of the Average and the JMA groups (P>.05).
CONCLUSIONS
No significant difference in the volume of occlusal adjustment was found when using occlusal devices made by using the digital average articulator or the JMA, suggesting that either method can be used to program articulators for the fabrication of occlusal devices.
PubMed: 37537106
DOI: 10.1016/j.prosdent.2023.06.018