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Journal of Oral Science Dec 2018To evaluate the occlusion accuracy of a novel impression technique, excessively high occlusion and the occlusal contact area during lateral movements were compared... (Comparative Study)
Comparative Study
To evaluate the occlusion accuracy of a novel impression technique, excessively high occlusion and the occlusal contact area during lateral movements were compared between metal restorations (restorations) and removable partial dentures (RPDs) fabricated using conventional and novel techniques. Both restorations and RPDs were fabricated on the simulation model with the precise displacement of the remaining teeth and soft tissue. For the novel technique, functionally generated path (FGP) recording and impression under occlusal force were simultaneously performed using a custom tray with an FGP table. For the two conventional techniques, definitive casts were mounted on an average value articulator and a semi-adjustable articulator in the typical manner. Prostheses were placed on the simulation models, and excessively high occlusion in the intercuspal position and occlusal contact areas during lateral movements were measured. Statistical analyses were performed using Kruskal-Wallis and Steel-Dwass tests (α = 0.05). For both prostheses, conventional techniques showed significantly higher occlusion in the intercuspal position than the novel technique. Moreover, the new technique demonstrated better guidance contact during lateral movements than conventional techniques. This novel technique can be recommended for the fabrication of highly accurate prostheses with appropriate occlusal contact without corrections at delivery.
Topics: Bite Force; Computer-Aided Design; Dental Impression Technique; Dental Materials; Dental Restoration, Permanent; Denture Design; Denture, Partial, Removable; Humans; Occlusal Adjustment
PubMed: 30158340
DOI: 10.2334/josnusd.17-0461 -
Applied Bionics and Biomechanics 2018Occlusal splints, to some extent, have been related to reduced body sway in a static position and increased muscle activity in the upper limbs. However, how dental...
Occlusal splints, to some extent, have been related to reduced body sway in a static position and increased muscle activity in the upper limbs. However, how dental occlusion status affects sports performance remains unclear. Here, we investigated whether occlusal splints that reposition the temporomandibular joint (TMJ) influenced body posture, muscle activity, and performance in 10-meter pistol shooters. Thirteen national-level male shooters (age = 38.8 ± 10.9 yrs) were recruited for this study, and cleared of any cervical pathology. An occlusal splint (OS) and a placebo splint (PS) were fabricated for each of the subjects, with the mandibular and maxillary position verified by an expert dentist, with the aid of an adjustable articulator. Surface electromyography (EMG) was assessed in the upper limb that holds the pistol while the subjects were standing on a force platform. Subjects performed two series of 10 shots for each of the three experimental conditions (OS, PS, N (no splint)) in randomized order, with the mandible in a rest position. Results revealed similar centre of pressure (COP) parameters in all conditions, despite a reduction in the average oscillation area caused by the OS. There were also no significant differences in EMG activity between conditions in the five upper limb muscles monitored. Consistent with this, shooting performance was similar in all conditions, despite a reduction in shot dispersion in subjects using OS. Thus, changes in dental occlusion status induced by OS do not affect body posture, upper limb EMG muscle activity, or shot performance in healthy male pistol shooters.
PubMed: 30140310
DOI: 10.1155/2018/9360103 -
Journal of Indian Prosthodontic Society 2018Determination of horizontal condylar guidance (HCG) by various clinical and radiographic methods was performed by several investigators. If a correlation between HCG...
CONTEXT
Determination of horizontal condylar guidance (HCG) by various clinical and radiographic methods was performed by several investigators. If a correlation between HCG values using lateral radiographic tracing and protrusive interocclusal records can be established, the necessity of performing elaborate recording procedures can be eliminated.
AIMS
The aim of this study is to evaluate and to compare the correlation between HCG values in edentulous people using the protrusive interocclusal records mounted on a semi-adjustable articulator with the manual tracing of panoramic radiograph and lateral cephalogram.
MATERIALS AND METHODS
A total of 20 completely edentulous individuals of either sex from 45 to 75 years (mean age 63.15 years) fulfilling the inclusion criteria were included in this study. In all the participants, HCG angles were determined clinically using protrusive interocclusal records and semi-adjustable articulator after intraoral gothic arch tracing. Radiographically, it was obtained by cephalometric tracing of panoramic radiograph and lateral cephalogram.
RESULTS
The present study shows mean HCG ± standard deviation (SD) of 28.17° ± 5.99° for interocclusal protrusive record while cephalometric tracing method yielded HCG ± SD of 38.95° ± 4.77° and 35.2° ± 4.94° for lateral cephalogram and orthopantomogram, respectively. A statistically significant positive correlation ( < 0.0001) was found among these three methods.
CONCLUSION
HCG can be successfully determined in edentulous participants by using three aforementioned methods. HCG values from cephalometric tracing of diagnostic radiographs can be used as an adjunct to the clinical method but cannot be used independently for programming a semi-adjustable articulator.
PubMed: 30111916
DOI: 10.4103/jips.jips_38_18 -
BioMed Research International 2018In recent years the T-Scan system has introduced the possibility of importing digitization of dental arches to its registrations. This is a remarkable advance, which...
In recent years the T-Scan system has introduced the possibility of importing digitization of dental arches to its registrations. This is a remarkable advance, which allows an intuitive display of the location of the gathered dynamic data on the denture. Nevertheless, today's usual method of manually positioning the arch in relation to the T-Scan's force registration gives rise to the possibility of human error. In order to guarantee a good alignment between the dynamic registration and 3D digital casts, a specific method was developed. The aim of this study is to evaluate the accuracy of this alignment method. For this purpose, it was compared with the most common procedure for detecting occlusal contacts, the articulating paper method. The comparison comprised overlapping digital models of both methods. Contacts of casts of 11 adults were registered, both with articulating paper and the T-Scan system. For one method, articulating paper marks were scanned in color; for the second method, the previously mentioned alignment was carried out with the T-Scan registrations. The results of both methods were overlapped in 3D digital casts, quantifying occlusal data matches. Statistical analyses were made to measure the quality of this alignment method. The study revealed a mean matching percentage of 79.02%, confirming the high reliability of the method.
Topics: Dental Arch; Dental Articulators; Dental Occlusion; Humans; Imaging, Three-Dimensional; Models, Dental; Reproducibility of Results
PubMed: 29977917
DOI: 10.1155/2018/8079089 -
Indian Journal of Dental Research :... 2018The objective of this study is to assess the utility of facebow transfer in the fabrication of occlusal splints, complete dentures and full arch fixed dental prosthesis.
OBJECTIVE
The objective of this study is to assess the utility of facebow transfer in the fabrication of occlusal splints, complete dentures and full arch fixed dental prosthesis.
MATERIALS AND METHODS
A systematic review protocol was registered at PROSPERO registry, University of York, UK (CRD42016041919). Following databases were explored: PubMed, CINAHL, Cochrane, and Web of knowledge. The PICO model included participants who received occlusal splint or complete denture or full arch fixed dental prosthesis at the centric relation position. The intervention was the use of facebow transfer. Comparators were prosthesis made without using a facebow. Outcomes were the patient satisfaction of the prosthesis and the need for laboratory adjustments. Only randomized clinical trials were included in the present review. A customized data extraction pro forma was used to extract the data and assess its quality.
RESULTS
A total of 505 articles were retrieved. On excluding duplicates, protocols, case reports, case series, narrative reviews, etc., only eight studies were selected for review. Six clinical trials on 249 complete dentures and two clinical trials on 65 occlusal splints were reviewed. No study on full arch crown and bridge work satisfied the inclusion criteria.
CONCLUSIONS
The use of facebow did not yield a superior fit or comfort of the complete dentures or occlusal splints. Therefore, there is no evidence of the utility facebow transfer for these prostheses. However, no inference could be drawn for its utility in full arch fixed dental prosthesis as there were no studies to draw an inference.
Topics: Centric Relation; Dental Articulators; Dental Prosthesis Design; Denture Design; Denture, Complete; Humans; Occlusal Splints
PubMed: 29900923
DOI: 10.4103/ijdr.IJDR_377_17 -
Journal of Clinical and Experimental... Jan 2018The search for the ideal, healthy and reproducible position of the condyles is of utmost importance for dental diagnosis and treatment. Thus, the objective of this...
BACKGROUND
The search for the ideal, healthy and reproducible position of the condyles is of utmost importance for dental diagnosis and treatment. Thus, the objective of this laboratory cross-sectional study was to verify the relationship between the posterior joint space and the mandibular lateral movements.
MATERIAL AND METHODS
Dental casts from 15 women and 15 men with normal mastication, 28 natural teeth and no history of temporomandibular disorders or pain, were fabricated and mounted on a fully adjustable articulator. From the maximum intercuspal position, condylar displacement was evaluated and measured on the working and nonworking sides during mandibular lateral movement, both to the right and left sides.
RESULTS
The correlation between the measures of interest was assessed with the Pearson correlation coefficient (α=.05). Condylar displacement on the working side and nonworking side condyle was 0.88±0.71 mm and 3.57±1.11 mm (right mandibular lateral movement); and 0.91±0.58 mm and 3.51±0.78mm (left mandibular lateral movement), respectively. No significant correlation in the condylar displacement between the working side condyles on the right and on the left sides was observed (r=.22; P=.248). The condylar poles of the articulator moved posteriorly, simulating the functional movements of the mandible during mastication. In all cases, condylar displacement during mandibular lateral movement both to the right and left occurred posteriorly on the working side condyle.
CONCLUSIONS
The condylar poles of the articulator moved posteriorly simulating the functional movements of the mandible during mastication. Moreover, left and right working condyles may require slightly different spaces to function, suggesting minor anatomical asymmetries. Mastication, dental occlusion, prosthodontics.
PubMed: 29670717
DOI: 10.4317/jced.54168 -
Journal of Indian Prosthodontic Society 2018The study was conducted to evaluate the accuracy of orthopantomograph (OPG) as an aid to determine condylar guidance.
PURPOSE
The study was conducted to evaluate the accuracy of orthopantomograph (OPG) as an aid to determine condylar guidance.
METHODOLOGY
The condylar guidance was measured using the impressions of glenoid fossae and radiographs (OPG) on thirty dried human skulls. Frankfurt horizontal plane (FHP) was used as a reference plane in both the methods and wire markers were adapted to make the contours of glenoid fossae discernible for both the methods. The condylar inclination angle was measured between FHP and a line joining the most concave point on the glenoid fossa with the most inferior point on the articular eminence on both right and left sides.
RESULTS
Pearson correlation was used for statistical analysis, and it showed a strong correlation between anatomic and radiographic methods ( = 0.864 for the left side, = 0.873 for the right side) as well as between right and left sides ( = 0.830). The data were also subjected to regression analysis (linear and panel estimation approach) which showed that OPG could be effectively used to predict the condylar guidance ( = 0.6160).
CONCLUSION
Although OPG shows a higher value than anatomic method, it can be used as an aid to set condylar guidance on semi-adjustable articulator.
PubMed: 29430140
DOI: 10.4103/jips.jips_243_17 -
Journal of Indian Prosthodontic Society 2018The purpose of this study was to compare and correlate sagittal condylar guidance determined by intraoral gothic arch tracing method and panoramic radiograph in...
A clinico-radiographic study to compare and co-relate sagittal condylar guidance determined by intraoral gothic arch tracing method and panoramic radiograph in completely edentulous patients.
PURPOSE
The purpose of this study was to compare and correlate sagittal condylar guidance determined by intraoral gothic arch tracing method and panoramic radiograph in edentulous patients.
MATERIALS AND METHODS
Twelve completely edentulous patients were selected by the inclusion and exclusion criteria. Conventional steps in the fabrication of complete denture till jaw relation were carried out. Intraoral gothic arch tracing and protrusive interocclusal records were obtained for each patient. Protrusive interocclusal record was used to program the Hanau Wide-Vue semi-adjustable articulator, thus obtaining the sagittal condylar guidance angle. Using RadiAnt DICOM software, on the orthopantomogram obtained for each patient in the study, two reference lines were drawn. The Frankfort's horizontal plane and the mean curvature line (joining the most superior and the inferior points on the glenoid fossa curvature) were drawn. The mean curvature line was extended to intersect the Frankfort's horizontal plane, thus obtaining the radiographic sagittal condylar guidance angle. The condylar guidance angles obtained by these two methods were compared and subjected to paired -test.
RESULTS
There was no statistically significant difference between the sagittal condylar guidance angles obtained between right and left sides with intraoral gothic arch tracing and radiographic methods ( = 0.107 and 0.07, respectively).
CONCLUSION
Within the limitations of this study, it was concluded that the protrusive condylar guidance angles obtained by panoramic radiograph may be used for programming semi-adjustable articulators.
PubMed: 29430137
DOI: 10.4103/jips.jips_207_17 -
Journal of Prosthodontics : Official... Jan 2019To study the effects of denture adhesive upon denture micromovements in three dimensions during the chewing of hard, sticky, and tough food items observed using a novel...
PURPOSE
To study the effects of denture adhesive upon denture micromovements in three dimensions during the chewing of hard, sticky, and tough food items observed using a novel method involving an electromagnetic articulograph (EMA) speech research system.
MATERIALS AND METHODS
Ten volunteers (mean age 60.9 ± 10.4 years) with fair- or poor-fitting complete maxillary dentures were enrolled. Chewing experiments were conducted using two treatments (adhesive or no-adhesive control) and three foods: carrots (hard), raisins (sticky), and processed meat stick (tough). Denture micromovement was measured through a novel application of a Northern Digital Wave EMA System. Three-dimensional denture position was captured during mastication using three sensors embedded into a replica denture for each subject. Following individual characterization of a "home" reference position, the Euclidean Distances from Home (DfH) were calculated for each recorded sample of the chewing experiments. The DfH at each sample represented the denture movement for that 1/100th of a second of the activity. The DfH data were then summarized as the mean DfH, the maximum DfH, and total distance traveled by the denture. Several thresholds were also analyzed, including the percent of time that the DfH ≥1.5 mm, ≥2.0 mm, and ≥2.5 mm.
RESULTS
With adhesive treatment, the mean DfH of dentures during chewing was reduced by 26.8% for carrot, 30.3% for raisin, and 31.0% for meat stick, when compared with no-adhesive treatment (p < 0.001 for all comparisons). Similar results were also seen for the maximum DfH and total distance travelled endpoints across foods. For the threshold endpoints, adhesive treatment was associated with a statistically significant reduction in denture micromovements at all three thresholds across foods. At the threshold of DfH ≥ 1.5 mm, adhesive treatment was associated with a reduction in micromovement by 61.6%, 56.2%, and 70.0% with carrot, raisin, and meat stick, respectively (p ≤ 0.004 for all comparisons).
CONCLUSIONS
Observations of denture movement using the Wave EMA System were able to differentiate systematically between adhesive treatment and no-adhesive treatment for denture micromovements during different chewing challenges. Use of adhesive was associated with statistically significant reductions in denture micromovements for hard, sticky, and tough foods as measured with both distance and threshold endpoints.
Topics: Acrylic Resins; Aged; Dental Articulators; Dental Cements; Denture Design; Denture Retention; Denture, Complete, Upper; Electromagnetic Phenomena; Female; Food; Food Preferences; Humans; Male; Mastication; Maxilla; Middle Aged; Movement
PubMed: 29136307
DOI: 10.1111/jopr.12679 -
Journal of Dentistry (Tehran, Iran) Mar 2017In completely edentulous patients, limited interarch distance can compromise conventional prosthetic fabrication. Bone reduction through various surgical procedures has...
In completely edentulous patients, limited interarch distance can compromise conventional prosthetic fabrication. Bone reduction through various surgical procedures has been recommended to restore an acceptable interarch distance. In such circumstances, a surgical guide built on a mounted cast can be used to minimize and control the amount of bone reduction performed. In the present report, an innovative method of fabrication of surgical guide has been described.
PubMed: 29104602
DOI: No ID Found