-
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 -
Journal of Clinical Medicine May 2022Information about full-digital protocols for bite registration with intraoral scanners on multiple implants in the edentulous jaw is scarce. The purpose of this...
OBJECTIVE
Information about full-digital protocols for bite registration with intraoral scanners on multiple implants in the edentulous jaw is scarce. The purpose of this comparative in vivo study was to investigate the reliability and time efficiency of a novel full-digital bite registration technique for the manufacture of full-arch maxillary fixed implant prostheses.
MATERIAL AND METHODS
In ten patients, a full-arch maxillary fixed implant prosthesis was manufactured on multi-unit abutment level through an analog prosthetic workflow. The bite registration was performed with use of a screw-retained polymethyl methacrylate (PMMA) verification jig with detachable wax rim. To articulate the definitive edentulous maxillary implant cast in centric relation at the appropriate occlusal vertical dimension (OVD) to the mandibular antagonist cast, a type II articulator (Artex, Amann Girrbach) was used. Three to six months later, a full-digital bite registration was performed with use of dual-function scan bodies and bilateral connected bite pillars. The bite pillars screwed into the scan bodies were used to adjust and articulate the edentulous maxillary implant arch to the mandibular antagonist arch at the defined OVD. Treatment time for analog and digital bite registration technique was measured in each patient. The reliability of the digital bite registration technique was evaluated by 3D comparison of two sets of stereo lithographic (STL) files obtained from each patient. The three-dimensional deviation was defined along the X-, Y- and -axes (Geomagic Control X, 3D Systems Inc., Rock Hill, SC, USA).
RESULTS
The treatment time for digital bite registration using dual-function scan bodies and bite pillars was significantly shorter than analog bite registration with verification jig and wax rim (60.30%, SD 5.72%). Minor differences between the two techniques were observed with a linear deviation range of 1115 µm (SD 668 µm) overall, 46.2 µm (SD 731.3 µm) along the -axis, -200.3 µm (SD 744.3 µm) along the -axis and 67.1 µm (SD 752.2 µm) along the -axis. Bilateral balanced contacts were registered in all patients during full-digital bite registration.
CONCLUSIONS
The novel digital bite registration technique with dual-function scan bodies and bite pillars allows for a full-digital workflow for full-arch implant supported restorations. The digital bite workflow was 60% faster, and the overall deviation was around 1 mm, which can be considered clinically acceptable.
PubMed: 35629010
DOI: 10.3390/jcm11102882 -
Journal of Indian Prosthodontic Society 2021The Aim of the study was to evaluate the reproducibility of condylar inclination values obtained using three different interocclusal recording materials in Hanau... (Randomized Controlled Trial)
Randomized Controlled Trial
Comparative evaluation of condylar guidance obtained by three different interocclusal recording materials in a semi-adjustable articulator and digital panoramic radiographic images in dentate patients: An study.
AIM
The Aim of the study was to evaluate the reproducibility of condylar inclination values obtained using three different interocclusal recording materials in Hanau Wide-Vue semi-adjustable articulator and to compare those values of condylar inclination with panoramic radiographic images.
SETTINGS AND DESIGN
In Vivo Comparative study.
MATERIALS AND METHODS
The clinical trial was carried out in the Department of Prosthodontics, M. R Ambedkar Dental College and Hospital, Bengaluru. A total of 30 dentulous subjects aged between 20 and 40 years were selected, without any signs and symptoms of temporomandibular joint disorders. With the help of a custom-made protrusive guide, protrusive records for three materials were made. These records were used for programming the articulator and the respective horizontal condylar inclination (HCI) value, and panoramic radiographs were made. The values obtained were statistically analyzed.
STATISTICAL ANALYSIS USED
Independent t-test, multiple comparisons using Bonferroni method followed by Analysis of variances (ANOVA) were used.
RESULTS
Among each pair of groups there exists a significant difference, i.e., the mean condylar inclination (degree) was found to be statistically significant between wax and polyvinyl siloxane (P < 0.01) as well as between wax and polyether (P < 0.01). No significant difference was observed between polyvinyl siloxane and polyether (P > 0.05).
CONCLUSION
HCI values differed depending on the type of material employed. The study concluded that the protrusive condylar guidance angles obtained by panoramic radiograph can be used in programming the semi-adjustable articulator and among the materials polyether gave the highest Condylar Guidance values with less variability and wax gave lowest values with greater variation.
Topics: Adult; Dental Articulators; Humans; Jaw Relation Record; Mandibular Condyle; Radiography, Dental, Digital; Radiography, Panoramic; Reproducibility of Results; Young Adult
PubMed: 34810368
DOI: 10.4103/jips.jips_239_21 -
The Journal of Prosthetic Dentistry May 2023Some contemporary articulator systems claim to be highly precise in their interchangeability, with tolerances below 10 μm in vertical error; however, the claims have...
STATEMENT OF PROBLEM
Some contemporary articulator systems claim to be highly precise in their interchangeability, with tolerances below 10 μm in vertical error; however, the claims have not been independently verified.
PURPOSE
The purpose of this study was to investigate the interchangeability of calibrated semiadjustable articulators in service over time.
MATERIAL AND METHODS
A calibrated mounting articulator served as the master articulator, while the test groups were used articulators with a minimum of 1-year use by predoctoral dental students (n=10); used articulators with a minimum of 1-year use by prosthodontic residents (n=10); and new articulators (n=10). One set of mounted maxillary and mandibular master models was positioned in the master and test articulators. High-precision reference markers on the master models were used to determine interarch 3D distance distortions (dR, dR, and dR), interocclusal 3D distance distortion (dR), interocclusal 2D distance distortions (dx, dy, and dz), and interocclusal angular distortion (dθ) relative to the master articulator. All measurements were conducted three times using a coordinate measuring machine and then averaged to derive the final data set.
RESULTS
For interarch 3D distance distortion, the mean dR ranged from 4.6 ±21.6 μm for new articulators to 56.3 ±47.6 μm for articulators used by prosthodontic residents; mean dR ranged from 65 ±48.6 μm for new articulators to 119.0 ±58.8 μm for articulators used by prosthodontic residents; and mean dR ranged from 12.7 ±39.7 μm for articulators used by prosthodontic residents to 62.8 ±75.2 μm for new articulators. For interocclusal 3D distance distortion, the mean dR ranged from 21.5 ±49.8 μm for new articulators to 68.6 ±64.9 μm for articulators used by predoctoral dental students. For the 2D distance distortions, the mean dx ranged from -17.9 ±43.4 μm for articulators used by predoctoral dental students to -61.9 ±48.3 μm for articulators used by prosthodontic residents; mean dy ranged from 18.1 ±59.4 μm for new articulators to 69.3 ±115.1 μm for articulators used by prosthodontic residents; and mean dz ranged from 29.5 ±20.2 μm for new articulators to 70.1 ±37.8 μm for articulators used by prosthodontic residents. Mean dθ ranged from -0.018 ±0.289 degree for new articulators to 0.141 ±0.267 degree for articulators used by prosthodontic residents. One-way ANOVA by articulator type revealed statistically significant differences among the test groups for dR (P=.007) and dz (P=.011) only, where articulators used by prosthodontic residents fared significantly poorer than the other test groups.
CONCLUSIONS
The new and used articulators tested did not fulfill the manufacturer's claim of accuracy of up to 10 μm in the vertical dimension. Up to 1 year of time in service, none of the investigated test groups fulfilled the criterion for articulator interchangeability, even if the more lenient threshold of 166 μm were accepted.
PubMed: 37244795
DOI: 10.1016/j.prosdent.2023.04.009 -
Scientific Data Dec 2023The use of real-time magnetic resonance imaging (rt-MRI) of speech is increasing in clinical practice and speech science research. Analysis of such images often...
The use of real-time magnetic resonance imaging (rt-MRI) of speech is increasing in clinical practice and speech science research. Analysis of such images often requires segmentation of articulators and the vocal tract, and the community is turning to deep-learning-based methods to perform this segmentation. While there are publicly available rt-MRI datasets of speech, these do not include ground-truth (GT) segmentations, a key requirement for the development of deep-learning-based segmentation methods. To begin to address this barrier, this work presents rt-MRI speech datasets of five healthy adult volunteers with corresponding GT segmentations and velopharyngeal closure patterns. The images were acquired using standard clinical MRI scanners, coils and sequences to facilitate acquisition of similar images in other centres. The datasets include manually created GT segmentations of six anatomical features including the tongue, soft palate and vocal tract. In addition, this work makes code and instructions to implement a current state-of-the-art deep-learning-based method to segment rt-MRI speech datasets publicly available, thus providing the community and others with a starting point for developing such methods.
Topics: Adult; Humans; Dental Articulators; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Speech
PubMed: 38042857
DOI: 10.1038/s41597-023-02766-z -
Journal of Prosthodontic Research Oct 2022Acquiring adequate attached mucosa is important in restoring masticatory function with a removable dental prosthesis or dental implant. In patients with inadequate...
PURPOSE
Acquiring adequate attached mucosa is important in restoring masticatory function with a removable dental prosthesis or dental implant. In patients with inadequate attached mucosa, a free gingival graft (FGG) with a custom stent is used. However, it is challenging to apply the conventional method for fabricating a stent with a reshaped cast in patients with reconstructed mandibles because the reconstructed mandible has limitations due to a titanium mesh, skin flap, and unique bone morphology. In the present report, we have proposed a new design and fabrication process for a mucocompressive splint via medical engineering to acquire the attached mucosa for the prosthodontic treatment of reconstructed mandibles.
METHODS
Three-dimensional (3D) craniomandibular models were reconstructed from a computed tomography dataset after mandibular reconstruction. The dentition region was replaced with highly precise scan data of the dental casts using a 3D scanner. The alveolar ridge mucosa and teeth were ideally designed using the 3D model while referring to the anatomical structures. The jig used to fabricate the working dental cast with artificial gum in real space was designed and fabricated using a 3D printer. The alveolar ridge was altered into a simulated configuration on the articulator using a jig. A mucocompressive splint was fabricated on an altered dental cast. The splint was immediately seated on the mandible without any major adjustments after the FGG.
CONCLUSION
Adequate attached mucosa for the prosthodontic treatment of a reconstructed mandible was obtained by the pre-surgical fabrication of a mucocompressive splint through medical engineering.
Topics: Dental Implants; Humans; Mandible; Mandibular Reconstruction; Splints; Titanium
PubMed: 35067490
DOI: 10.2186/jpr.JPR_D_21_00160 -
Journal of Psycholinguistic Research Dec 2023Generalization in motor control is the extent to which motor learning affects movements in situations different than those in which it originally occurred. Recent data...
Generalization in motor control is the extent to which motor learning affects movements in situations different than those in which it originally occurred. Recent data on orofacial speech movements indicates that motor sequence learning generalizes to novel syllable sequences containing phonotactically illegal, but previously practiced, consonant clusters. Practicing an entire syllable, however, results in even larger performance gains compared to practicing just its clusters. These patterns of generalization could reflect language-general changes in phonological memory storage and/or inter-articulator coordination during motor sequence learning. To disentangle these factors, we conducted two experiments in which talkers intensively practiced producing novel syllables containing illegal onset and coda clusters over two consecutive days. During the practice phases of both experiments, we observed that, through repetition, talkers gradually produced the syllables with fewer errors, indicative of learning. After learning, talkers were tested for generalization to single syllables (Experiment 1) or syllable pairs (Experiment 2) that overlapped to varying degrees with the practiced syllables. Across both experiments, we found that performance improvements from practicing syllables with illegal clusters partially generalized to novel syllables that contained those clusters, but performance was more error prone if the clusters occurred in a different syllable position (onset versus coda) as in practice, demonstrating that inter-articulator coordination is contextually sensitive. Furthermore, changing the position of a cluster was found to be more deleterious to motor performance during the production of the second syllables in syllable pairs, which required talkers to store more phonological material in memory prior to articulation, compared to single syllables. This interaction effect reveals a complex interplay between memory storage and inter-articulator coordination on generalization in speech motor sequence learning.
Topics: Humans; Speech; Dental Articulators; Linguistics; Language; Speech Perception; Phonetics
PubMed: 37488461
DOI: 10.1007/s10936-023-09998-5 -
Case Reports in Dentistry 2022In this article, two cases with generalized dental wear and four cases with localized dental wear are reported. In some of the cases, the worn teeth were restored with...
BACKGROUND
In this article, two cases with generalized dental wear and four cases with localized dental wear are reported. In some of the cases, the worn teeth were restored with direct composite techniques with no mock-up and articulator mounting according to the canine rise method. This method is used without any change in the intercuspation of posterior teeth without a muscle relaxation appliance. It introduces a stable occlusal condition that can alter neuromuscular reflex activity, leading to improvements in certain muscle pain disorders. It is also used to protect the teeth and supporting structures from abnormal forces that might create a further breakdown and/or tooth wear.
METHODS
The first step of treatment in all the cases was a composite build-up for maxillary and mandibular canines to restrict and guide the horizontal and vertical jaw movements and create adequate space for restorations. The second step was the placement of direct or indirect restorations on upper and lower anterior teeth efficiently and accurately.
RESULTS
This method enhanced the esthetic outcomes in a conservative approach with no reduction in tooth material or time-consuming treatments.
CONCLUSIONS
This technique can be suggested for the treatment of worn teeth in patients with Angle's Cl I and Cl II classifications of malocclusion based on the follow-up results. It is not applicable for the treatment of worn teeth in patients with Angle's class III because occlusion is reversed, and canine teeth do not have guidance role. . This method significantly reduces the overall treatment time, and additional steps are required to restore the worn-out teeth and/or occlusion using the canine rise method.
PubMed: 35265380
DOI: 10.1155/2022/9949879 -
Annals of African Medicine 2023During complete denture fabrication making Interocclusal records plays an integral role to obtain the condylar guidance value. The study was conducted to compare the...
BACKGROUND AND PURPOSE
During complete denture fabrication making Interocclusal records plays an integral role to obtain the condylar guidance value. The study was conducted to compare the protrusive condylar guidance registration by two interocclusal recording materials-Quick setting plaster and Luxabite®(bisacrylic composite) in semi adjustable articulator for completely edentulous patients.
METHODOLOGY
Maxillary and Mandibular casts of the completely edentulous patients were mounted in Hanau®Wide Vue articulator. The Quick setting plaster and Luxabite®(bisacrylic composite) was used as interocclusal recording materials to program the protrusive condylar guidance angles in the articulators.
RESULTS
The protrusive condylar guidance values registered in the articulator for the different interocclusal records were tabulated and statistically analyzed.. The mean protrusive condylar guidance values registered in the articulator was compared with two parameters obtained from the radiographic tracings -- the protrusive condylar path angle obtained with Quick setting plaster and Luxabite with the inclination of articular eminence to the Frankfort horizontal plane.
CONCLUSION
From the study it was concluded that the Luxabite®(bisacrylic composite) material demonstrated better reproducibility of protrusive condylar guidance registration.than the Quick setting plaster.
Topics: Humans; Mandibular Condyle; Jaw Relation Record; Reproducibility of Results; Mandible; Resin Cements
PubMed: 37417019
DOI: 10.4103/aam.aam_70_22 -
Contemporary Clinical Dentistry 2022The aim of the study was to determine the effect of different anterior reference points during facebow transfer, on sagittal inclination of occlusal plane (SIOP) and...
AIM
The aim of the study was to determine the effect of different anterior reference points during facebow transfer, on sagittal inclination of occlusal plane (SIOP) and horizontal condylar guidance (HCG) values obtained on arcon and nonarcon articulators.
MATERIALS AND METHODS
Facebow records of 25 participants were made and transferred to Hanau Wide-Vue (WV) and Hanau H2 (H2) articulators using conventional indirect transfer (CIT), superior annular groove (SAG), and inferior annular groove (IAG) as anterior reference points. Maxillary casts were mounted on each articulator followed by mandibular mountings. Protrusive interocclusal record was used to determine HCG, and SIOP was measured as an angle between the occlusal plane of mounted maxillary cast and upper member of the articulator. Both, HCG and SIOP were measured on a digital lateral cephalogram and the values obtained were compared with previously determined values from both the articulators. Intergroup comparison was done by analysis of variance and pair-wise comparison by Tukey test.
RESULTS
Values of SIOP significantly ( = 0.00) changed on both the articulators when CIT, SAG, and IAG were the anterior reference points. The ratio of SIOP and HCG on both articulators was comparable to that of the cephalogram for CIT, IAG, but it was substantially low for SAG.
CONCLUSIONS
The variation of anterior reference point changes the value of SIOP recorded on Hanau WV and H2 articulators; however, it had no effect on HCG values recorded on both the articulators. The angle between SIOP and HCG changed with variations in superior-inferior position of the mountings on both articulators.
PubMed: 36213845
DOI: 10.4103/ccd.ccd_1035_20