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Medicina (Kaunas, Lithuania) Jul 2023Learning to speak properly requires a fully formed brain, good eyesight, and a functioning auditory system. Defective phonation is the outcome of a failure in the... (Review)
Review
Learning to speak properly requires a fully formed brain, good eyesight, and a functioning auditory system. Defective phonation is the outcome of a failure in the development of any of the systems or components involved in speech production. Dentures with strong phonetic skills can be fabricated with the help of a dentist who has a firm grasp of speech production and phonetic characteristics. Every dentist strives to perfect their craft by perfecting the balance between the technical, cosmetic, and acoustic aspects of dentistry, or "phonetics". The ideal prosthesis for a patient is one that not only sounds good but also functions well mechanically and aesthetically. Words are spoken by using articulators that alter their size and form. : Therefore, a prosthesis should be made in such a way that it does not interfere with the ability to communicate. As a result, a prosthodontist has to have a solid grasp of how speech is made and the numerous parts that go into it.
Topics: Humans; Speech; Phonetics; Phonation; Learning; Brain
PubMed: 37512133
DOI: 10.3390/medicina59071322 -
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 -
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 Prosthodontics : Official... Feb 2024This paper presents a method for the digital transfer of the upper maxillary arch position using a facebow, a transfer table, and a reference block with a CAD...
This paper presents a method for the digital transfer of the upper maxillary arch position using a facebow, a transfer table, and a reference block with a CAD application without requiring physical casts mounted with articulating gypsum. This technique facilitates the prosthetic digital workflow when the impression is made via intraoral scanning, to obtain the placement of the maxillary arch in the anatomical reference planes and in relation to the axes of rotation of the mandibular movements.
Topics: Dental Articulators; Mandible; Maxilla; Workflow; Computer-Aided Design
PubMed: 37209310
DOI: 10.1111/jopr.13703 -
European Journal of Dental Education :... Feb 2024This study evaluated the self-assessment skills of third-year dental students regarding their performance in complete removable prosthodontics (CRP) preclinical course.
INTRODUCTION
This study evaluated the self-assessment skills of third-year dental students regarding their performance in complete removable prosthodontics (CRP) preclinical course.
METHODS AND MATERIALS
This cross-sectional study was conducted on all third-year dental students attending the International Dental College of Tehran University of Medical Sciences. The students were requested to self-assess their performance in primary impression making, custom tray fabrication, border moulding, final impression making, master cast fabrication, record-base fabrication and tooth arrangement in CRP preclinical course. The performance of dental students in each step was scored by themselves and their mentors. Data were analysed by the Mann-Whitney U, Pearson's correlation and t-tests (α = 0.05).
RESULTS
Totally 25 male (55.6%) and 20 female (44.4%) dental students were evaluated. Significant differences were noted between male and female dental students in self-assessment scores regarding adequate extension of the custom tray (p = .027), the correct position of tray handle (p = .020), visibility of vestibular width and depth on the cast (p = .011), the coincidence of upper and lower midlines (p = .005) and correct orientation of maxillary and mandibular planes in the articulator (p = .036). The mean self-assessment score of female students was significantly higher than that of male students (p = .01). The scores given by the mentors were not significantly different for male and female students (p = .975). The difference between the self-assessment score of students and the mentor score was not significant (p = .067) either in males or in females (p > .05).
CONCLUSION
Undergraduate dental students favourably self-assessed their performance in all steps of the preclinical course of CRP, comparable with their mentor assessment.
Topics: Humans; Male; Female; Self-Assessment; Students, Dental; Prosthodontics; Cross-Sectional Studies; Education, Dental; Iran
PubMed: 37145242
DOI: 10.1111/eje.12909 -
The Journal of Prosthetic Dentistry Apr 2024The alignment of the maxillary and mandibular digital scans obtained with an intraoral scanner (IOS) generates digital interocclusal records. Although the accuracy of...
STATEMENT OF PROBLEM
The alignment of the maxillary and mandibular digital scans obtained with an intraoral scanner (IOS) generates digital interocclusal records. Although the accuracy of maxillary and mandibular digital scans obtained from an IOS is widely studied, the accuracy of digital interocclusal records obtained with them is not; even less studied is the accuracy (trueness and precision) of the alignment methods that are available to obtain them.
PURPOSE
The purpose of this in vitro study was to assess the precision under repeatability conditions (repeatability) of the different alignment methods used to obtain digital interocclusal records.
MATERIAL AND METHODS
Digital scans of maxillary and mandibular casts of a dentate healthy adult were acquired with an IOS. Casts were then mounted in maximum intercuspal position in a semi-adjustable mechanical articulator (1801 AR Model PSH Articulator), and left and right occlusal digital scans were acquired with the IOS. Occlusal digital scans were repeated 7 times under repeatability conditions. After obtaining each pair of occlusal digital scans, the software program of the IOS automatically aligned the maxillary and mandibular digital scans with occlusal digital scans (TRI method), resulting in 7 digital interocclusal records composed of aligned maxillary and mandibular digital scans and occlusal digital scans. All 7 sets of aligned digital scans were exported and realigned in a dental computer-aided design software program by means of global and reference alignment methods (EXO-B and EXO-R methods, respectively). To assess the repeatability, the 7 aligned digital scan sets of each group were repositioned in the common coordinate system by aligning maxillary digital scans, and repeatability was calculated in terms of the distance between the vertices of the mandibular digital scans for each of the possible nonrepeating combinations of pairs (C=21). The repeatability was tested by using the Kruskal-Wallis test for nonparametric distribution followed by the Mann-Whitney U test and Bonferroni correction for pairwise comparisons (α=.05).
RESULTS
The median with interquartile range for the TRI alignment method was 47 (27) μm for the EXO-B method 41 (25) μm and 16 (5) μm for EXO-R. The Kruskal-Wallis test showed statistical difference between test groups (P<.05). The post hoc Dunn test with Bonferroni adjustment detected significant statistical differences between the EXO-R-TRI (P<.001) and EXO-R-EXO-B (P<.001) alignment methods.
CONCLUSIONS
This study found that the alignment method could influence the repeatability of digital interocclusal records. The reference best-fit alignment method (EXO-R) provided better repeatability.
Topics: Imaging, Three-Dimensional; Models, Dental; Dental Impression Technique; Software; Computer-Aided Design
PubMed: 36115710
DOI: 10.1016/j.prosdent.2022.07.014 -
European Journal of Dental Education :... Aug 2023This study aimed to investigate the difference between senior dental students and prosthodontic faculty members regarding their opinions, attitudes and adoption of six...
INTRODUCTION
This study aimed to investigate the difference between senior dental students and prosthodontic faculty members regarding their opinions, attitudes and adoption of six split-cast techniques for remounting complete dentures. The accuracy of each technique for measurements of the vertical and the anteroposterior dimensions was assessed.
MATERIALS AND METHODS
Six split-cast techniques to remove the casts were compared. A total of 115 participants removed a set of casts on six different articulators, and a questionnaire survey was administered. A digital Vernier caliper was used to measure the linear dimensional changes between the laterally pindexed references on each cast. The data were statistically analysed at α = 0.05.
RESULTS
There were significant differences between senior dental students and prosthodontic faculty members in their responses regarding adoption of daily practice and techniques requiring more skill (p = .001). To adopt a specific technique in daily practice, most students and faculty members chose long round die pins (36.4%) and central groove indexing (CGI; 40.7%), respectively. For techniques requiring more skills, most students and faculty members chose long rectangular die pins (30.7%) and short round dowel pins (33.3%), respectively.
CONCLUSION
Dental students preferred ShRP, whilst faculty members preferred LReP. All participants considered CGI to be the easiest amongst the techniques. For comparison with baseline measurements, both senior dental students and prosthodontic faculty members considered side notch indexing and double dowel pins to be the most accurate techniques for vertical measurements, and CGI for anteroposterior measurements.
Topics: Humans; Dental Articulators; Education, Dental; Prosthodontics; Faculty; Surveys and Questionnaires
PubMed: 35881669
DOI: 10.1111/eje.12841 -
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 -
The Journal of Prosthetic Dentistry Jan 2024Although average values and facebow records have been incorporated into prosthetic dentistry with much success, little is known about how using 3D facial scans for...
STATEMENT OF PROBLEM
Although average values and facebow records have been incorporated into prosthetic dentistry with much success, little is known about how using 3D facial scans for mounting compare with traditional mounting methods.
PURPOSE
The purpose of this pilot clinical study was to determine differences in measurements among casts mounted virtually by using the average values of the Bonwill triangle and the Balkwill angle, casts mounted by using facebow records, and casts mounted from 3D facial scans.
MATERIAL AND METHODS
Intraoral digital scans were obtained from each participant (n=10) and 3D printed in resin. For the facebow preservation group (FPG), a facebow record was used to mount the resin casts on a semiadjustable articulator. A desktop scanner was used to digitize this mounting while preserving the facebow record. The average mounting group (AMG) consisted of intraoral digital scans that were mounted virtually by using the concepts of the Bonwill triangle and the Balkwill angle. For the facial scan group (FSG), the participants' digitized casts were superimposed on the facial scans by using a target system. The Bergstrom point and the glabella were used to mount these casts and their associated facial scans in the digital environment. This study used the FPG as the group to compare with the other mounting techniques because of its wide acceptance in restorative dentistry. These virtual mountings were completed in a computer-aided design software program, and the distance from right and left condylar elements to the incisal embrasure between mandibular central incisors, distance from left mandibular first molar to left condylar element and from right mandibular first molar to right condylar element, and anterior and posterior recordings at 0 mm, 3 mm, and 5 mm of vertical dimension increase were recorded. A Kruskal-Wallis 1-way analysis of variance was performed (α=.05). The Mann-Whitney U test was performed to evaluate differences in measured values among groups, and multiple comparisons were adjusted by using Bonferroni correction.
RESULTS
All anterior and posterior measurements to the condylar elements of the virtual articulator were found to be significantly different (P<.05). Both anterior and posterior condylar measurements between the FPG and the AMG were found to be significantly different (P<.05), while comparisons between the FPG and the FSG were found not to be significantly different (P>.05). All changes in vertical dimension were found not to be significantly different with respect to both anterior and posterior measurements (P>.05).
CONCLUSIONS
When used to virtually mount dental casts, 3D facial scanners performed similarly to traditional facebow records.
Topics: Humans; Jaw Relation Record; Models, Dental; Face; Computer-Aided Design; Dental Articulators
PubMed: 35382941
DOI: 10.1016/j.prosdent.2022.03.001 -
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