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Journal of Maxillofacial and Oral... Jun 2022The goal was to perform an orthognathic surgery laboratorial study to evaluate the reproducibility of the resulting movements from virtual surgical planning (VSP), by...
PURPOSE
The goal was to perform an orthognathic surgery laboratorial study to evaluate the reproducibility of the resulting movements from virtual surgical planning (VSP), by comparing the measurements obtained from VSP to those obtained from Erickson's platform using the 3D printed surgical guide.
METHODS
Eight patients who had undergone orthognathic surgery were screened and grouped according to maxillary movement and the patient's dentofacial deformity. Three-D virtual surgery simulations were performed, and surgical guides were obtained using Dolphin Imaging 11.9® software. In a semi-adjustable articulator (SAA), the maxilla model was separated from the SAA mounting platform, and the surgical guide was used to reassemble it. Then, the maxilla model was fixed and transferred to Erickson's platform to verify the planned movement. The data were submitted for statistical analysis.
RESULTS
The agreement between the methods was excellent, regardless of direction, landmark analyzed, or the amount of movement. The most considerable variation was 0.42 mm in the movement amplitude of 6 mm, and the highest mean was 0.07 mm in the region of the superior right first molar (16).
CONCLUSION
Therefore, regardless the movement of the maxilla, no statistically significant difference was observed between the measurements obtained through VSP and Erickson's platform, demonstrating that both methods are equally accurate and reliable.
PubMed: 35712388
DOI: 10.1007/s12663-022-01687-5 -
The Journal of Advanced Prosthodontics Apr 2016The purpose of this study was to determine the effect of changes in the horizontal plane angle on the mesiodistal width ratios of the maxillary anterior teeth during the...
PURPOSE
The purpose of this study was to determine the effect of changes in the horizontal plane angle on the mesiodistal width ratios of the maxillary anterior teeth during the acquisition of frontal view photographs, derive these ratios for Korean adults on the basis of the data obtained, and analyze them using the Golden Proportion as a reference.
MATERIALS AND METHODS
In experiment I, 30 plaster casts were mounted on an articulator and positioned on the angle-measuring device with a center setting of 0°. The device was rotated to 10° in 1° increments in a counterclockwise direction. At each angle, photographs were obtained and analyzed. Experiment II was based on 60 patients who visited the Department of Prosthodontics at Kyungpook National University Dental Hospital from February 2012 to February 2015. The patients were divided into three groups [Male (M), Female (F), Total (M + F)]. Frontal views were obtained for all groups and analyzed.
RESULTS
From 1° to 10°, the relative mesiodistal width ratios for the maxillary anterior teeth showed no significant differences from those at 0°. In all three groups, the relative width ratio of the maxillary central incisor was smaller than that specified in the Golden Proportion; the opposite was true for the canine.
CONCLUSION
Our results suggest that the mesiodistal width ratios of the maxillary anterior teeth do not follow the Golden Proportion in Korean adults, and that a change in the horizontal plane angle from 1° to 10° during frontal photography does not affect these ratios.
PubMed: 27141256
DOI: 10.4047/jap.2016.8.2.125 -
Journal of Prosthodontics : Official... Mar 2019Mounting casts accurately on an articulator is a prerequisite for the treatment planning/execution of complex dental cases that require occlusal rehabilitation. A full...
Mounting casts accurately on an articulator is a prerequisite for the treatment planning/execution of complex dental cases that require occlusal rehabilitation. A full digital approach to transfer the position of maxillary dentition to a virtual articulator, by using intraoral scans and cone beam computed tomography (CBCT) files is presented. This technique offers reduced chairside time and the flexibility of choosing the orientation plane. It can be used in orthognathic surgeries, complex interdisciplinary treatments requiring a CBCT scan with a large field of view, or treatments that already have the head CT or CBCT scans from previous diagnosis/treatment.
Topics: Cone-Beam Computed Tomography; Dental Articulators; Imaging, Three-Dimensional; Maxilla; Models, Dental; Patient Care Planning
PubMed: 30663165
DOI: 10.1111/jopr.13023 -
Journal of Pharmacy & Bioallied Sciences Jul 2014The difficulty in reproducing accurate angle of condylar guidance in semi-adjustable articulators.
INTRODUCTION
The difficulty in reproducing accurate angle of condylar guidance in semi-adjustable articulators.
PURPOSE
The purpose of this study was to determine the correlation between the angle of horizontal condylar inclination obtained on a semi-adjustable articulator and the corresponding angle traced on a temporomandibular joint (TMJ) radiograph in completely edentulous subject.
MATERIALS AND METHODS
The horizontal condylar inclination angle was obtained in a semi-adjustable articulator by means of height tracer (extra oral tracing device) and interocclusal records to program the articulator in 21 subjects. TMJ radiograph were recorded by the same operator with same orthopantomogram (OPG) machine (planmeca). Tracings of inclines of articular eminence on the radiograph were compared with the angle obtained on a semi-adjustable articulator. Each measurement was made using manual methods of measuring angle. The results were subjected to the Pearson correlation statistical analysis (α =0.01).
RESULTS
The outline of the articular eminence in a TMJ tomogram radiographic image was identified and traced. A significant correlation was found between the horizontal condylar inclination on a semi-adjustable and the corresponding TMJ tomogram radiographic image for both right (R = 0.789; P = 0.001) and left (i = 0.747; P = 0.004) sides.
CONCLUSION
The articular eminence traced on a TMJ tomogram image represents the horizontal condylar inclination with a mean difference of 5° in 21 subjects evaluated.
PubMed: 25210356
DOI: 10.4103/0975-7406.137421 -
The Saudi Dental Journal Sep 2023Digitalized workflow eliminates the need for the tray, impression materials, its decontamination, packaging and shipping, pouring with plaster, cast fabrication,...
Digitalized workflow eliminates the need for the tray, impression materials, its decontamination, packaging and shipping, pouring with plaster, cast fabrication, mounting in an articulator, reducing storage spaces, and the risks of any loss or fracture of the plaster model is overcome by archiving on the computer. This clinical investigation aimed to evaluate the effectiveness of the fully digitalized rehabilitation [implant-supported prosthesis] method in partially edentulous patients and with TMD, using advanced software. Twelve patients requiring implant-supported prosthesis in the mandibular molar area with Temporomandibular disorders [TMD] were selected. The fully digitalized rehabilitation method with advanced software was used for rehabilitation. For each subject, Optical impressions, CBCT scan, and Digital recording of jaw movement data. Guided implant surgery and digitalized prosthetic rehabilitation; were performed. The effectiveness of the digitalized workflow was assessed by evaluating the changes in the joint symptoms before and after the end of the treatment, changes in the electromyographic tracings, the precision of the prosthetic artefact, assessed through the amount of chair adjustment operating time and the number of retouching/ modifications to be carried out before the completion of the work. The results showed that the mean operative time required in 12 patients was 9.42 min, significantly less than the time recorded in previous studies when the medium mean was 16.00 min. The mean number of touch-ups [adjustments] was less than 3, most of which were on the interproximal surfaces. There were no significant changes recorded in the electromyography tracings. There were also no changes in joint symptoms. It was found that this way of working was entirely reliable and significantly reduced operating times and the number of appointments. Digital flow is beneficial ei dysfunctional patients, not about improvements in temporomandibular symptoms but in times of operability and prosthetic retouching.
PubMed: 37817790
DOI: 10.1016/j.sdentj.2023.05.024 -
Beijing Da Xue Xue Bao. Yi Xue Ban =... Feb 2008To explore virtual semi-adjustable articulator for complete denture computer aided design (CAD) system, and to simulate biting motion and virtual occlusal adjustment for...
OBJECTIVE
To explore virtual semi-adjustable articulator for complete denture computer aided design (CAD) system, and to simulate biting motion and virtual occlusal adjustment for a complete denture CAD digital model.
METHODS
The edentulous jaw casts, rims and bite records of forward protrusion were made in clinic. The casts were fixed to the articulator and inclination of protrusive condylar guidance was set up with bite records of forward protrusion. Inclination of lateral condylar guidance was calculated and set up with Hanus formula. Inclination of protrusive incisal guidance inclination was calculated and set up with ratios of over bite and overjet of complete denture CAD digital model which have been designed with Complete Denture CAD System. The 3D locus data of semi-adjustable articulator was obtained by scanning three points on articulator with contact head of FARO ScanArm (FARO Technologies Inc., American). In the same scanning coordinate system, the laser scanner was used to get labial/buccal surface data of rims at centric relation position. Based on rims, the coordinate system was set up and the complete denture CAD model was aligned to the locus data. The virtual articulator program was explored with Scoll language offered by Imageware (EDS corp., American). The 3D biting motion simulating, automatic occluding relation detection and automatic occlusal adjustment functions were supported by the program.
RESULTS
A virtual semi-adjustable articulator program for Complete Denture CAD System was explored and applied to a complete denture CAD digital model. With the program, 3D biting motion simulating, automatic occluding relation detection and automatic occlusal adjustment can be realized.
CONCLUSION
A technical route of virtual articulator is set up based on semi-adjustable articulator and initial approach is carried out for application of the virtual articulator in CAD progress of complete denture.
Topics: Computer-Aided Design; Dental Articulators; Denture Design; Denture, Complete; Humans
PubMed: 18278149
DOI: No ID Found -
Journal of Pharmacy & Bioallied Sciences Jun 2013To evaluate and compare the variations in the inclination of occlusal plane of casts mounted on Artex articulator using a facebow with a fixed value and customized...
Evaluation of the inclination of maxillary occlusal plane on mounted casts using a fixed value and customized nasion indicator in artex articulator: Facebow system - An in-vivo comparative study.
AIM
To evaluate and compare the variations in the inclination of occlusal plane of casts mounted on Artex articulator using a facebow with a fixed value and customized nasion indicator.
MATERIALS AND METHODS
Twenty two subjects were selected for this investigation. Two maxillary impressions were made, and casts poured. For each of the twenty two subjects, the facebow records were made with, Artex face-bow using a fixed value nasion indicator and customized nasion indicator and mounted. The angle between the occlusal plane of upper cast and the upper articulator arm was measured with a Universal bevel protractor and compared with the gold standard cephalometric value.
RESULTS
It shows that, when angle was measured between maxillary occlusal plane and upper member of the articulator, on the mounted cast using a customized nasion indicator and fixed value nasion indicator against the gold standard cephalometric value as a whole, it was found to be not significant. But, if each patient were evaluated individually, there found to be the difference in the angle.
DISCUSSION AND CONCLUSION
Variation in occlusal plane was very minimal and close to the cephalometric value when using customized nasion indicator compared to fixed value nasion indicator on the Artex.
PubMed: 23946578
DOI: 10.4103/0975-7406.113297 -
Journal of Oral Rehabilitation May 2019Some occlusal detection products are designed for use on dry teeth, but this is not always achieved. Others are suited for dry and wet applications.
BACKGROUND
Some occlusal detection products are designed for use on dry teeth, but this is not always achieved. Others are suited for dry and wet applications.
OBJECTIVE
The objective of this study is to assess the combined effects, on occlusal contact forces, of two previously studied affecting variables-occlusal detection products and saliva.
METHODS
We used a full-arch dentiform with three occlusal detection products (an articulating film, an articulation paper and T-Scan) in combination with human (HS) and an artificial saliva. The maxillary arch assembly, weighing ~54 N (the maximum bite force), was lowered onto (occlusion) and lifted off (disclusion) of the mandibular arch through 10 cycles by a mechanical testing machine. The forces and moments acting on the mandibular arch were continuously recorded by a load cell that supported it.
RESULTS
The maximum values of F (the in-occlusal plane component of the occlusal contact force) were analysed by occlusion/disclusion separately using one-way ANOVA, with factor for group type to identify the significant effect of salivas on products, effect of products, effect of salivas with products, effect of human saliva. A difference in occlusion and/or in disclusion was considered different. Statistical differences (P < 0.0001) in F were found in: dry product vs product + HS, dry product vs product + artificial saliva (with articulating film and T-Scan) and HS vs product + HS (with articulation paper and T-Scan).
CONCLUSION
All products were affected by the salivas, except articulation paper by artificial saliva.
Topics: Analysis of Variance; Biomechanical Phenomena; Bite Force; Dental Articulators; Dental Stress Analysis; Humans; Jaw Relation Record; Models, Dental; Reproducibility of Results; Saliva; Stress, Mechanical; Surface Properties
PubMed: 30702766
DOI: 10.1111/joor.12772 -
Journal of Indian Prosthodontic Society Dec 2012Centric relation (CR) has been considered mainly as a position posterior to habitual occlusion or maximum intercuspation (MI). Awareness of the tooth contacts...
Centric relation (CR) has been considered mainly as a position posterior to habitual occlusion or maximum intercuspation (MI). Awareness of the tooth contacts relationship in centric relation position of the mandible and diagnosing the case from this position is essential to consistently select treatment plans that will allow to treat to or very near to centric relation occlusion. Centric slide and other occlusal relationships are conceived of as positions, which can be studied in three dimensions. Clinically, the difference between the two occlusal positions namely CR and MI (centric slide) can easily be determined, but for a more precise evaluation of its length and directions, an occlusal analysis on articulator mounted casts is necessary. Study was under taken on the mounted casts of ten subjects on a semi adjustable articulator to which a stylus and recording table was devised and attached for measurement of CR-MI slide in the three planes namely anterior-posterior, medio-lateral and superior-inferior. It was found that there was a displacement from CR to MI (centric slide) in all the three planes and numerically the mean slide was 0.688 ± 0.623, 0.261 ± 0.627 and 0.127 ± 0.541 mm in the antero-posterior, medio- lateral and superior-inferior directions respectively. The stylus and table attachment may be an accurate indirect method to measure positional changes of the condyle in 3D.
PubMed: 24293918
DOI: 10.1007/s13191-012-0130-0 -
Medicina Oral, Patologia Oral Y Cirugia... Jan 2013Given the need to ensure that dentists are sufficiently skilled to offer the best possible care to their patients, this study aims to evaluate the teaching methods and...
OBJECTIVES
Given the need to ensure that dentists are sufficiently skilled to offer the best possible care to their patients, this study aims to evaluate the teaching methods and clinical experience achieved by undergraduate dental students in Spain and Portugal as regards complete dentures.
STUDY DESIGN
In February 2011, a questionnaire seeking information about the preclinical and clinical teaching of complete dentures was e-mailed to all Spanish and Portuguese dental schools with fully developed undergraduate degree dental programs.
RESULTS
A response rate of 82.6% was obtained. The distribution of lectures and hours spent at the laboratory and in clinical activities revealed that teaching complete dentures is eminently a practical issue, this being mostly performed by full-time prosthodontists. All surveyed schools teach the design of the record base, and most of them instruct students in the mounting of teeth in wax. Most schools (94.7%) used a semiadjustable articulator, alginate for primary impressions (73.7%) and elastomeric materials in border-molded custom trays for final impressions (68.4%). In most schools, within the clinical setting students work in pairs, the mean student/ professional staff member ratio being 2.3 ± 0.7. Most schools perform a competence-based assessment (83.3%), although innovative techniques such as problem-based learning are still rarely applied. On average, the students emplaced 1.8 ± 1.2 complete dentures during their clinical training, ranging from 0 to 4, although no clear trend was seen as regards the minimum number of dentures to be made for graduating.
CONCLUSIONS
Variations in teaching programs and clinical experience concerning complete denture curricula among Spanish and Portuguese dental schools are evident, but all the schools base their teaching mainly on preclinical and clinical practice. However, the low number of dentures made by student per year seems insufficient to ensure clinical skills and cope with social needs.
Topics: Curriculum; Denture, Complete; Education, Dental; Portugal; Schools, Dental; Spain; Surveys and Questionnaires
PubMed: 23229249
DOI: 10.4317/medoral.18078