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The Journal of Advanced Prosthodontics Oct 2023This study aimed to compare the accuracy of the conventional facebow system and the newly developed POP (PNUD (Pusan National University Dental School) Occlusal Plane)...
PURPOSE
This study aimed to compare the accuracy of the conventional facebow system and the newly developed POP (PNUD (Pusan National University Dental School) Occlusal Plane) bow system for occlusal plane transfer in asymmetric ear position.
MATERIALS AND METHODS
Two dentists participated in this study, one was categorized as Experimenter 1 and the other as Experimenter 2 based on their clinical experience with the facebow (1F, 2F) and POP bow (1P, 2P) systems. The vertical height difference between the two ears of the phantom model was set to 3 mm. Experimenter 1 and Experimenter 2 performed the facebow and POP bow systems on the phantom model 10 times each, and the transfer accuracy was analyzed. The accuracy was evaluated by measuring the angle between the reference virtual plane (RVP) of the phantom model and the experimental virtual plane (EVP) of the upper mounting plate through digital superimposition. All data were statistically analyzed using a paired -test ( < .05).
RESULTS
Regardless of clinical experience, the POP bow system (0.53° ± 0.30 (1P) and 0.19° ± 0.18 (2P) for Experimenter 1 and 2, respectively) was significantly more accurate than the facebow system (1.88° ± 0.50 (1F) and 1.34° ± 0.25 (2F), respectively) in the frontal view ( < .05). In the sagittal view, no significant differences were found between the POP bow system (0.92° ± 0.50 (1P) and 0.73° ± 0.42 (2P) for Experimenter 1 and 2, respectively) and the facebow system (0.82° ± 0.49 (1F) and 0.60° ± 0.39 (2F), respectively), regardless of clinical experience ( > .05).
CONCLUSION
In cases of asymmetric ear position, the POP bow system may transfer occlusal plane information more accurately than the facebow system in the frontal view, regardless of clinical experience.
PubMed: 37936837
DOI: 10.4047/jap.2023.15.5.271 -
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 -
Beijing Da Xue Xue Bao. Yi Xue Ban =... Feb 2020To evaluate the three-dimensional (3D) reconstruction accuracy of the intercuspal occlusion (ICO) of the dental casts, by the dental articulator position method, and...
OBJECTIVE
To evaluate the three-dimensional (3D) reconstruction accuracy of the intercuspal occlusion (ICO) of the dental casts, by the dental articulator position method, and provide a reference for clinical application.
METHODS
The standard dental casts in ICO were mounted on average values articulator, and five pairs of milling resin cylinders were respectively attached to the base of both the casts. 100 μm articulating paper and occlusal record silicone rubber were used to detect the occlusal contact number between the posterior teeth of casts mounted on articulator in ICO. The occlusal contact numbers NA detected by the two methods were calculated simultaneously, as the reference. After the upper and lower casts were scanned separately, and the buccal data of casts in ICO were scanned with the aid of the dental articulator position, registration was carried out utilizing the registration software. Then the digital casts mounted in ICO as well as the buccal occlusal data were saved in standard tessellation language (STL) format. Geomagic Studio 2013 software was used to analyze the contact number NS between digital upper and lower casts by the "deviation analysis" function. The differences were compared between N and N, to evaluate the sensitivity and positive predict value (PPV) of the model scanner to reproduce the occlusal contact with the aid of dental articulator position. The distance D between the centers of the circles at the top surface of the upper and lower corresponding cylinders was obtained by the three-coordinate measuring system Faro Edge, as the reference value. The Geomagic Studio 2013 software was used to construct the cylinders of digital casts and the distance D between the centers of the circles at the top surface of the corresponding cylinders were measured, as the test value. The one-sample T test was used to analyze the variable differences between D and D.
RESULTS
The PPV of reproducing the occlusal contact point was 0.76 and sensitivity was 0.81. The distance error of the opposite cylinder was (0.232±0.089) mm. There was no statistical difference between the feature points 5-5', while there were statistical differences between the other feature points.
CONCLUSION
By the dental articulator position method, the model scanner reproduces the occlusal contact point with high sensitivity and PPV, and that meets clinical needs. Meanwhile, the distance between the feature points is greater than the reference value, which will lead to occlusal disturbance, and require clinical grinding.
Topics: Dental Articulators; Dental Occlusion; Imaging, Three-Dimensional; Jaw Relation Record; Models, Dental; Software
PubMed: 32071477
DOI: 10.19723/j.issn.1671-167X.2020.01.022 -
Journal of Pharmacy & Bioallied Sciences Nov 2021The aim of this study was to conduct a cross-sectional questionnaire-based survey concerning the practice of occlusal splint for treating temporomandibular disorders...
AIM
The aim of this study was to conduct a cross-sectional questionnaire-based survey concerning the practice of occlusal splint for treating temporomandibular disorders (TMDs) by the dental practitioners of Jabalpur.
MATERIALS AND METHODS
A questionnaire containing questions on diagnosis, treatment, and management of TMD was given to a total of 157 general dental practitioners in Jabalpur. The responses were collected; data analysis was done by Chi-square test.
RESULTS
Of the General Dental Practitioner's, nearly 78% of participants did not attend any continuing dental education on TMD per year. More than 10 years of experience (82%) was associated with increase in positive response for treatment of TMD patient. Both the diagnosis and treatment of TMD patient were done using combination methods. The duration of splint use was considered patient dependent (42.27%) irrespective of the years of practice. Soft splint was most commonly employed for treatment, and fabrication of splint was done on hinge and mean value articulator.
CONCLUSION
The knowledge of occlusal splint by general practitioners was found to be insufficient for treating TMDs.
PubMed: 35017933
DOI: 10.4103/jpbs.jpbs_157_21 -
BMC Oral Health Mar 2023Precise occlusal design of implant-supported fixed prostheses is difficult to achieve by the conventional wax-up method, often requiring chairside adjustments. The...
BACKGROUND
Precise occlusal design of implant-supported fixed prostheses is difficult to achieve by the conventional wax-up method, often requiring chairside adjustments. The computer-aided design (CAD) method is promising. This study aims to compare the occlusal contacts and clearance of posterior implant-supported single crowns designed by the CAD and conventional methods.
METHODS
Sample size calculation indicated fourteen samples per group. Two sets of type-IV plaster casts with a single implant analog inserted in the posterior teeth region were mounted as master casts in a mechanical articulator in maximal intercuspal position (MIP). Seven working cast sets were obtained from each master cast by a closed tray technique, and mounted in MIP. Two implant-supported single crowns were designed with an occlusal clearance to achieve light occlusal contact in each working cast set by CAD and conventional method, separately. For the CAD group, the crown was designed in digital models obtained by scanning the working casts. For the conventional group, wax-up of the crown was prepared on the working casts and scanned to generate a STL file. In the working and master casts, mean and minimum occlusal clearances in the designed occlusal contact area of the both finished prostheses were calculated using the occlusal clearance (OC) and occlusal record (OR) method. The prostheses' occlusion was evaluated in master casts.
RESULTS
For the evaluation in the working casts, both design methods had similar mean occlusal clearances by the OC method (195.4 ± 43.8 vs. 179.8 ± 41.8 μm; P = 0.300), while CAD group resulted in a significantly larger minimum occlusal clearance in the designed occlusal contact area (139.5 ± 52.3 vs. 99.8 ± 43.8 μm; P = 0.043). Both design methods had similar mean and minimum occlusal clearances by the OR method (P > 0.05). For the evaluation in the master casts, both design techniques had similar mean and minimum occlusal clearances, number and distribution of occlusal contacts, and lateral interference ratios (P > 0.05).
CONCLUSION
Occlusal contact and clearance of posterior implant-supported single crowns designed by the CAD method can be at least as good as those designed by the conventional wax-up method.
Topics: Humans; Crowns; Computer-Aided Design; Dental Occlusion; Research Design; Dental Impression Technique; Dental Prosthesis Design
PubMed: 36918877
DOI: 10.1186/s12903-023-02847-w -
Cureus May 2023This clinical report details the successful rehabilitation of a 63-year-old male patient with severe tooth wear, a reduced vertical dimension of occlusion, and esthetic...
This clinical report details the successful rehabilitation of a 63-year-old male patient with severe tooth wear, a reduced vertical dimension of occlusion, and esthetic concerns. The Hobo twin-stage procedure addressed these issues while improving the patient's oral health and quality of life. After ensuring adequate oral hygiene, the treatment began with scaling and root planning, followed by diagnostic impressions. An occlusal splint was fabricated, followed by a diagnostic wax-up and tooth preparation. Full-arch impressions of prepared teeth were made using the addition of silicon elastomeric impression material, and chairside provisional crowns were fabricated. The working casts were mounted on a semi-adjustable articulator, and the metal copings were tried on before being built up in porcelain. The patient achieved successful outcomes and expressed satisfaction with the treatment. The Hobo twin-stage technique and porcelain-fused-to-metal crowns can be viable approaches for restoring the teeth's form and function while enhancing the patient's oral health and esthetics. However, regular follow-up appointments and good oral hygiene maintenance are essential for the long-term success of the treatment.
PubMed: 37378250
DOI: 10.7759/cureus.39260 -
BioMed Research International 2022This study is aimed at evaluating the impact of the craniofacial structure and occlusal conditions on the position of the articular heads of the mandibular condyles in...
PURPOSE
This study is aimed at evaluating the impact of the craniofacial structure and occlusal conditions on the position of the articular heads of the mandibular condyles in the maximum intercuspal position (MIP) and comparing the centric relation (CR) and MIP of the mandibular condyles prior to orthodontic treatment.
METHODS
The studied group consisted of 33 women and 15 men (median age of 17.75 years). Contact points of opposing teeth in the MIP were assessed by hand-held casts. Condylar displacement (CD) in three spatial planes on both sides was measured on models mounted in an articulator using a mandibular position indicator (MPI). Patients were divided into groups according to craniofacial structures (vertical and horizontal growth directions). The Mann-Whitney, Kruskal-Wallis, post hoc Dwass-Steel-Critchlow-Fligner, and Pearson's independence tests as well as Spearman's nonparametric correlations were used in the statistical analyses.
RESULTS
Within the limitations of this study, no statistically significant correlation of CD with certain cephalometric measurements from a lateral cephalometric radiograph (ANB, SN-ML, and SGo/NMe) was observed. Correlation, however, was found between condylar displacement in the transverse axis and the mandibular plane angle SN-ML ( = 0.033) and also between condylar displacement in the anteroposterior axis and a midline shift of the mandible ( = 0.041). The results revealed a relationship between Angle's classification of molar position on the right side and anteroposterior CD values ( = 0.006).
CONCLUSIONS
Cephalometric measurements cannot be used to predict CD at the level of the condyles. Analysis of occlusal conditions of models mounted in an articulator is desirable for patients with Angle's class I and lower jaw asymmetry.
Topics: Adolescent; Centric Relation; Cephalometry; Dental Articulators; Female; Humans; Jaw Relation Record; Male; Mandible; Mandibular Condyle
PubMed: 35097107
DOI: 10.1155/2022/1439203 -
Journal of Indian Prosthodontic Society 2021This study aimed to evaluate the combined influence of condylar and incisal guidance in canine-guided and group function occlusal schemes.
AIMS
This study aimed to evaluate the combined influence of condylar and incisal guidance in canine-guided and group function occlusal schemes.
SETTINGS AND DESIGN
In vivo - Cross sectional study.
MATERIALS AND METHODS
A total number of 88 subjects were selected and classified into two groups: 44 subjects with canine guided and 44 subjects with group function occlusal schemes. Condylar and incisal guidance tracings of both the groups were recorded using SAM AXIOQUICK RECORDER (School Articulator Munich) and evaluated.
STATISTICAL ANALYSIS USED
Kolmogorov-Smirnov test and Shapiro-Wilk test were employed to test the normality of data. Independent sample t-test and Mann-Whitney U-test was performed for quantitative variables.
RESULTS
The condylar and incisal guidance among canine-guided individuals was 31.38 ± 12.01 and 55.83 ± 14.04, respectively, while in group function individuals, it was 29.44 ± 12.65 and 43.74 ± 20.27.
CONCLUSIONS
Within the limitations of the present study, condylar guidance was similar in subjects with both schemes of occlusion, whereas steeper incisal guidance was noticed in canine-guided individuals as compared to group function.
Topics: Animals; Cross-Sectional Studies; Dogs; Humans; Mandibular Condyle; Statistics, Nonparametric
PubMed: 34380812
DOI: 10.4103/jips.jips_183_21 -
Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi... Jun 2023This study aimed to compare the effects of virtual adjustment on occlusal interferences in mandibular posterior single crown and three-unit bridge restorations by using... (Comparative Study)
Comparative Study
OBJECTIVES
This study aimed to compare the effects of virtual adjustment on occlusal interferences in mandibular posterior single crown and three-unit bridge restorations by using the mandibular movement track and the movement parameters of a virtual articulator.
METHODS
Twenty-two participants were recruited. Digital casts of the maxillary and mandibular arches were obtained using an intraoral scanner, and the jaw registration system was used to record the data of the mandibular movement track and the movement parameters of the articulator. Four kinds of restorations with 0.3 mm occlusal interferences were designed with dental design software. In particular, single crowns were designed for teeth 44 and 46, whereas three-unit bridges were designed for teeth 44-46 and 45-47, and the corresponding natural teeth were virtually extracted. Virtual adjustment of the restorations was performed using two dynamic occlusal recordings, namely, the mandibular movement track and the movement parameters of the virtual articulator. A reverse-engineering software was used to measure the root-mean-square of the three-dimensional deviation of the occlusal surfaces between natural teeth and the adjusted restorations. The differences between the two methods of virtual-occlusion adjustment were compared and analyzed.
RESULTS
For the same group of restorations, the three-dimensional deviation of the mandibular movement track group were lower than those of the virtual articulator group, and the differences were statistically significant (<0.05). For the four groups of restorations adjusted by the same method, the three-dimensional deviation of the 46-tooth single crown was the largest and the smallest three-dimensional deviation was that of the 44-tooth single crown. Statistical differences existed between the 44-tooth single crown and the other groups (<0.05).
CONCLUSIONS
For the occlusal design of posterior single crown and three-unit bridge, the mandibular movement track could be a more effective approach to virtual occlusal adjustment than the movement parameters of the virtual articulator.
Topics: Humans; Mouth, Edentulous; Occlusal Adjustment; Jaw Relation Record; Dental Articulators; Software
PubMed: 37277790
DOI: 10.7518/hxkq.2023.2022452 -
Journal of Indian Prosthodontic Society 2020Identification and establishment of the occlusal plane in patients with impaired occlusal plane, presents a major hurdle for the execution of natural esthetics, speech,...
AIMS
Identification and establishment of the occlusal plane in patients with impaired occlusal plane, presents a major hurdle for the execution of natural esthetics, speech, and function. The aim of this study was to minimize such errors while occlusal rehabilitation, and employ hamular notchincisive papilla (H.I.P) plane as landmark and scribe it on the cast using H. I. P evaluator and utilise for occlusal corrections.
SETTINGS AND DESIGN
HIP plane being parallel to the occlusal plane could ease the operator when it could be scribed on cast to analyze and restore the compromised occlusal plane.
MATERIALS AND METHODS
Dentulous casts of two hundred participants were mounted on the Hanau Wide-Vue articulator. Reference points were marked on the maxillary right central incisor and maxillary molars on casts for attaining different occlusal planes, the incisive papilla and hamular notch region were also marked for HIP plane. A plane parallel HIP was scribed on cast using HIP Evaluator. The casts were then scanned using a three-dimensional coordinate measuring machine attached to perception V5 laser scanner and measurements were made using Geomagic X design software. The most parallel occlusal plane to HIP plane was evaluated, and the reliability of HIP evaluator was verified.
STATISTICAL ANALYSIS USED
ANOVA test, -Bonferroni test, and independent sample ""-test were carried out for the comparison between occlusal planes, among the genders and for the analysis of the angle of deviation of scribed plane on the cast to HIP plane on the right and left sides.
RESULTS
Occlusal plane III (Mesio-labial incisal edge of upper right central incisor to Mesio-buccal cusp tips of upper second molars) showed least angle of deviation with 1.316° ± 1.158° to HIP plane among tested subjects. There is no significant difference between the genders. The plane scribed on the cast with H. I. P evaluator showed relative parallelism to H. I. P plane with minimum deviation of 0.010° ± 0.363°.
CONCLUSION
Occlusal plane III is more parallel to H. I. P plane. Scribed plane on the cast using H. I. P evaluator is parallel to H. I. P plane. H. I. P evaluator can be used as an alternative tool to establish the occlusal plane to rehabilitate patient with deficient dentition or disordered occlusal plane.
PubMed: 32089600
DOI: 10.4103/jips.jips_167_19