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Toxins May 2022The physiological homeostasis of the masticatory complex in short-faced patients is too robust to be disintegrated and reconstructed due to the powerful masseter muscle.... (Clinical Trial)
Clinical Trial
Can Botulinum Toxin-A Contribute to Reconstructing the Physiological Homeostasis of the Masticatory Complex in Short-Faced Patients during Occlusal Therapy? A Prospective Pilot Study.
The physiological homeostasis of the masticatory complex in short-faced patients is too robust to be disintegrated and reconstructed due to the powerful masseter muscle. This study innovatively introduced the botulinum toxin-A (BTX-A) into the field of dental occlusal treatment, providing a novel and minimally invasive therapy perspective for the two major clinical problems in these patients (low treatment efficiency and high rates of complications). In total, 10 adult patients with skeletal low angle seeking occlusal treatment (age: 27.0 ± 6.1 years; 4 males and 6 females) were administered 30−50 U of BTX-A in each masseter muscle and evaluated before and 3 months after injection based on cone-beam computed tomography (CBCT). We found a significant reduction in the thickness of the masseter muscle (MMT) (p < 0.0001). With regards to occlusion, we found a significant increase in the height of the maxillary second molar (U7-PP) (p < 0.05) with significantly flattened occlusal curves (the curve of Spee [COS] (p < 0.01), and the curve of Wilson [COW] (p < 0.05)). Furthermore, the variations in the temporomandibular joint exhibited a significant reduction in the anterior joint space (AJS) (p < 0.05) and superior joint space (SJS) (p < 0.05). In addition, the correlation analysis of the masticatory complex provided the basis for the following multiple regression equation: MMT = 10.08 − 0.11 COW + 2.73 AJS. The findings from our pilot study indicate that BTX-A, as a new adjuvant treatment attempt of occlusal therapy for short-faced patients, can provide a more favorable muscular environment for subsequent occlusal therapy through the adjustment of the biting force and may contribute to the reconstruction of healthier homeostasis of the masticatory complex. However, further research is required to establish the reliability and validity of these findings.
Topics: Adult; Botulinum Toxins, Type A; Female; Homeostasis; Humans; Male; Pilot Projects; Prospective Studies; Reproducibility of Results
PubMed: 35737035
DOI: 10.3390/toxins14060374 -
The Saudi Dental Journal Nov 2021Occlusal appliances can distribute aggressive loads which are generated by bruxism and can reduce their frequency. The facebow record, when used in the construction of...
BACKGROUND
Occlusal appliances can distribute aggressive loads which are generated by bruxism and can reduce their frequency. The facebow record, when used in the construction of occlusal appliances, helps in minimizing occlusal discrepancies. This study aimed to compare the effect of CAD/CAM stabilization occlusal splint made with and without facebow for management of bruxer patients.
METHOD
24 Patients who were diagnosed as bruxers were randomly assigned into two equal groups and obtained maxillary CAD/CAM occlusal stabilizing splint recorded with centric relation either with or without using a facebow. The patient satisfaction using the visual analog scale (VAS) was recorded at baseline, one month and three months' follow-up periods. The adjustment time of both splints, from the start of splint delivery until becoming well-fitted and occlusally adjusted, was calculated using a stopwatch.
RESULTS
The CAD/CAM occlusal splints with or without the use of facebow improved the patient's satisfaction with no statistically significant difference between both groups at baseline, one month and three months with p values of 0.73, 0.24 and 0.45 respectively. The comparison between the two modalities regarding the adjustment time showed no statistically significant difference between both groups (P = 0.06).
CONCLUSION
According to the results of this study; no difference was detected in patient satisfaction and the time required for adjustment of CAD/CAM occlus.
PubMed: 34803311
DOI: 10.1016/j.sdentj.2020.07.002 -
Journal of Clinical Medicine Dec 2020This clinical study was designed with the aim of fabricating four ceramic crowns using the conventional method and digital methods with three different intraoral...
This clinical study was designed with the aim of fabricating four ceramic crowns using the conventional method and digital methods with three different intraoral scanners and evaluate the marginal and internal fit as well as clinician satisfaction. We enrolled 20 subjects who required ceramic crowns in the upper or lower molar or the premolar. Impressions were obtained using digital scans, with conventional impressions (polyvinyl siloxane and desktop scanner) and three different intraoral scanners (EZIS PO, i500, and CS3600). Four lithium disilicate glass-ceramic crowns were fabricated for each patient. In the oral cavity, the proximal and occlusal adjustments were performed, and the marginal fit and internal fit were evaluated using the silicone replica technique. The clinician satisfaction score of the four crowns was evaluated as per the evaluations of the proximal and occlusal contacts made during the adjustment process and the marginal and internal fit. For statistical analysis, the differences among the groups were analyzed with one-way analysis of variance and Tukey HSD test as a post-test; Pearson correlation analysis was used for analyzing the correlations (α = 0.05). There was a significant difference in the marginal and internal fit of the ceramic crowns fabricated using three intraoral scanner types and one desktop scanner type ( < 0.001); there was a significant difference in the clinician satisfaction scores ( = 0.04). The clinician satisfaction score and marginal fit were significantly correlated (absolute marginal discrepancy and marginal gap) ( < 0.05). An impression technique should be considered for fabricating a ceramic crown with excellent goodness-of-fit. Further, higher clinician satisfaction could be obtained by reproducing the excellent goodness-of-fit using the intraoral scanning method as compared to the conventional method.
PubMed: 33327402
DOI: 10.3390/jcm9124035 -
Clinical Oral Implants Research Mar 2023To investigate the effect of a novel interocclusal recording method on the occlusal accuracy of implant-supported fixed prostheses for partially dentate patients with... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
To investigate the effect of a novel interocclusal recording method on the occlusal accuracy of implant-supported fixed prostheses for partially dentate patients with distal extension.
MATERIALS AND METHODS
Twenty patients with two or more adjacent teeth missing in the distal extension and scheduled to receive implant-supported fixed prostheses were enrolled. Two interocclusal recording methods were used: placing polyvinyl siloxane (PVS) on the interocclusal recording caps (test), and placing PVS on healing abutments (control). The intraoral occlusal contacts in maximal intercuspal position (MIP) were compared with those in the mounted casts to calculate sensitivity and positive predictive value (PPV). Then, patients were randomly allocated into two groups to determine which interocclusal record would be used. The implant prostheses' evaluations mainly included occlusal adjustment height, volume, and time, occlusal contact score based on articulating paper examination. Paired-samples t-test, Mann-Whitney U test, and least squares regression analyzed the statistic differences.
RESULTS
The test method had higher sensitivity to detect intraoral occlusal contacts than the control method (p = .002), but similar PPV (p = .10). During the prostheses' evaluations, the occlusal adjustment height in the test group was significantly lower than that in the control group [99.4 (53.2, 134.2) vs. 159.0 (82.3, 247.8) μm, p = .03], while the occlusal contact score before adjustment was higher (p = .006). The groups had similar occlusal adjustment volume and time.
CONCLUSIONS
The novel interocclusal recording method for implant-supported fixed prostheses was more accurate and could reduce the occlusal adjustment.
Topics: Humans; Dental Implants; Dental Prosthesis, Implant-Supported
PubMed: 36695644
DOI: 10.1111/clr.14040 -
Journal of Oral Rehabilitation Mar 2024Occlusal interferences lead to changes in mandibular kinematics to compensate and improve function. However, the effects of different types of eccentric disturbance on... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Occlusal interferences lead to changes in mandibular kinematics to compensate and improve function. However, the effects of different types of eccentric disturbance on the comminution capacity are not known.
OBJECTIVE
To determine the immediate effect of eccentric occlusal interferences on masticatory performance.
METHODS
This crossover clinical trial included 12 healthy dentate subjects aged 25.2 ± 3.3 years who were randomly submitted to seven types of occlusal interference: unilateral and bilateral laterotrusive and mediotrusive, protrusive, dummy and control (no interference). The interference forms were planned in a semi-adjustable articulator, fabricated with composite resin and adhered to the mandibular first molars such that subjects' maximum intercuspation was maintained. Masticatory performance and the chewing rate during 20 cycles were evaluated during subjects' comminution of silicone test food under one interference condition per test day; the multiple sieve method was applied to the comminuted particles. The interference was removed upon test completion, and a 1-week washout period was applied between tests.
RESULTS
Comminuted median particle sizes were larger under unilateral (4.94 ± 0.41 mm) and bilateral (4.81 ± 0.49 mm) laterotrusive, bilateral mediotrusive (4.65 ± 0.50 mm) and protrusive (4.83 ± 0.54 mm) interferences (p < .05) than under the control (4.01 ± 0.52 mm) and dummy (4.18 ± 0.58 mm) conditions (p < .05). Only unilateral and bilateral laterotrusive interferences narrowed the comminuted particle size dispersion (p < .05). The chewing rate did not differ among conditions (p = .1944).
CONCLUSION
Artificial eccentric interferences had an immediate adverse effect on masticatory performance by resulting in larger comminuted particles.
CLINICAL TRIAL REGISTRATION
Brazilian Registry of Clinical Trials (RBR-8g5zfg8).
Topics: Humans; Dental Occlusion; Mandible; Mastication; Molar; Particle Size; Double-Blind Method
PubMed: 37964439
DOI: 10.1111/joor.13620 -
The Journal of Prosthetic Dentistry May 2024Implant-supported crowns made in both fully and partially digital workflows have been evaluated, but these studies have been mainly performed in vitro. Moreover, data... (Randomized Controlled Trial)
Randomized Controlled Trial Comparative Study
A randomized clinical trial comparing the clinical fit and chairside adjustment time for implant-supported crowns fabricated by fully digital and partially digital techniques.
STATEMENT OF PROBLEM
Implant-supported crowns made in both fully and partially digital workflows have been evaluated, but these studies have been mainly performed in vitro. Moreover, data on the comparison of clinical fitting and adjustment time for implant-supported crowns are limited.
PURPOSE
The purpose of this randomized clinical trial was to evaluate the clinical fit and adjustment time for implant-supported crowns produced by a partially and fully digital workflow in partially edentulous participants.
MATERIAL AND METHODS
Twenty-eight participants who had received 2 adjacent implants in posterior sites were enrolled, each receiving 2 custom titanium abutments and a splinted monolithic zirconia restoration. Restorations of the control group (n=14) were produced from a digital scan and a cast-free digital workflow, while the restorations of the test group (n=14) were from a conventional impression and a partially digital workflow. A blinded investigator delivered the restorations. The clinical adjustment was performed incrementally, and a digital chronometer recorded the time required for the evaluation and adjustment at each step. An independent t test, Mann-Whitney U test, and the Fisher exact test were used to evaluate the results (α=.05).
RESULTS
The total mean adjustment time in the control group (12.49 minutes) was significantly longer than that of the test group (11.27 minutes) (P<.001). For the occlusal contact points, significantly less clinical adjustment time was required with the cast-free digital workflow (5.31 minutes) than with the model-based partially digital workflow (6.06 minutes) (P=.001). On other surfaces, no significant difference was found between the 2 groups (P>.05). All crowns could be successfully delivered after 2 clinical appointments (impression and delivery). Remakes were not necessary for any restorations in the test or control group.
CONCLUSIONS
The parameters of occlusal adjustment time and total adjustment time of the fully digital workflow were significantly shorter than those of the partially digital workflow.
Topics: Humans; Crowns; Dental Prosthesis, Implant-Supported; Female; Computer-Aided Design; Male; Middle Aged; Dental Prosthesis Design; Time Factors; Adult; Zirconium; Dental Marginal Adaptation; Dental Abutments
PubMed: 35525625
DOI: 10.1016/j.prosdent.2022.02.024 -
International Journal of Computerized... Mar 2022Virtual planning has become part and parcel of digital dentistry to ensure more precise planning, better treatment outcomes, and more effective communication between...
Virtual planning has become part and parcel of digital dentistry to ensure more precise planning, better treatment outcomes, and more effective communication between dental practitioners, dental technicians, and patients. In dentistry, CAD software programs are one way to achieve virtual treatment planning. Among the most crucial and critical steps in treatment planning and execution are virtual articulation and occlusal analysis of the maxillary and mandibular arches. These steps have a great influence on the success of the final outcome. The present article proposes a detailed method for constructing a novel virtual articulator that can also be used for educational purposes to enable occlusal analysis and adjustment for a virtual tooth mock-up by simulating a virtual dynamic occlusion through the use of open-source Autodesk Meshmixer software.
Topics: Dental Articulators; Dentists; Humans; Professional Role; Software; Workflow
PubMed: 35322654
DOI: No ID Found -
Journal of Dentistry Jun 2024The objective of this study was to analyze the occlusal contact characteristics of the food-impacted teeth using a new digital technique.
OBJECTIVES
The objective of this study was to analyze the occlusal contact characteristics of the food-impacted teeth using a new digital technique.
METHODS
A 3D occlusal analysis method was developed for studying the occlusal contact characteristics of teeth affected by food impaction. In this self-controlled study, food-impacted molars from 20 participants constituted the experimental group. The corresponding healthy teeth on the opposite side served as the control group. Variables such as occlusal force (OF), occlusal contact area (OCA), and the number and distribution of occlusal contact points (OCN) in the mesio-distal directions were measured and compared between the two groups.
RESULTS
There was no statistical significant difference in the values of OF, OCA and OCN between the food-impacted molars and the healthy control molars (P > 0.05). However, paired T-tests indicated significant difference in the proportion of mesial OF, OCA, and OCN in the second molars of the experimental group (0.22, 0.28 and 0.28, respectively) and the control group (0.66, 0.63, and 0.63 respectively) (P < 0.001).
CONCLUSIONS
The abnormal distribution of occlusal contacts in the second molar, primarily characterized by excessive occlusal contact in the distal direction may contribute to the occurrence of food impaction.
CLINICAL SIGNIFICANCE
The present study identified variations in the distribution of occlusal contacts and occlusal component force in food-impacted teeth. These findings can assist dentists in making more targeted occlusal adjustments, or applying other treatment modalities, to effectively address food impaction.
PubMed: 38880468
DOI: 10.1016/j.jdent.2024.105133 -
Clinical Oral Implants Research Nov 2019To compare the three-dimensional changes in quantity and morphology following clinical adjustment of a posterior single implant crown between chairside digital workflow... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
To compare the three-dimensional changes in quantity and morphology following clinical adjustment of a posterior single implant crown between chairside digital workflow (test) and hybrid digital workflow (control).
MATERIALS AND METHODS
A total of 33 participants were included for single-tooth replacement with screw-retained crowns in posterior sites of either the maxillary or mandible. A total of 17 participants were carried to a chairside digital workflow, receiving monolithic lithium disilicate (LS2)-crowns (test), while the remaining 16 participants were fitted with CAD/CAM-fabricated zirconia superstructures and hand-layered ceramic veneering crowns (control). As each crown underwent intraoral scanning (3Shape TRIOS Color, 3Shape), 3D digital models were rendered. These scans were taken both before and after try-in. Clinical adjustment dimensional changes were measured by superimposing the optical scans of models within a reverse software (Geomagic Control 2014). Adjustment counts and amounts (from vertical dimension) between two workflows were assessed and compared. Time consumption was recorded for efficiency analysis.
RESULTS
All patients were successfully treated in both groups. The median maximum vertical adjustment (taking both occlusal and interproximal surfaces into consideration) was 237 μm ± 112 in the test group and 485 μm ± 195 in the control group (p < .0001), respectively. The median adjustment count was 2.00 ± 1.09 in test group and 3.00 ± 1.05 in control group (p = .001), respectively. The total active working time/ total time for two workflows was 92.3/113.7 min for the test group and 146.3/676.3 min for the control group, respectively.
CONCLUSION
The test group showed fewer adjustments and apparent precision on the occlusal surface compared with the control group with only a fifth of the consumption of a hybrid workflow.
Topics: Computer-Aided Design; Crowns; Dental Porcelain; Dental Prosthesis Design; Humans; Workflow
PubMed: 31357225
DOI: 10.1111/clr.13519 -
Journal of Dentistry Mar 2024This study aimed to assess the effectiveness of patient-specific motion in restoring anterior guidance and to investigate the influence of occlusal plane position within...
OBJECTIVES
This study aimed to assess the effectiveness of patient-specific motion in restoring anterior guidance and to investigate the influence of occlusal plane position within a virtual articulator on the design of the anterior guide slope for incisors.
METHODS
Twenty participants' intraoral scan, occlusal plane position, and jaw motion data were recorded. The maxillary anterior teeth were virtually prepared, and the crowns were designed based on average virtual articulator (AVR), personalized virtual articulator (ART), and patient-specific motion (PSM). The anterior guide slope of maxillary central incisors (S, S, S, S) and the mesio-distal angle (MDA) of the canine of prostheses were compared to that of natural teeth (NAT). One-Way ANOVA was utilized to evaluate the effectiveness of the three methods in restoring the anterior guidance of maxillary anterior teeth.
RESULTS
The comparison of S and MDA showed no significant difference between the PSM and NAT groups (p > 0.05). However, S of the ART group was significantly smaller, while MDA was higher than that of the NAT group (p < 0.05). S did not differ significantly (p > 0.05) when the angle of the occlusal plane (AOP) was small. As the AOP increased, S of the ART and AVR groups were significantly smaller than that of the NAT group (p < 0.05). With a large AOP, S of the ART group was notably smaller than that of the NAT group (p < 0.05), while there was no significant difference between the AVR and NAT groups (p > 0.05).
CONCLUSIONS
Occlusal design based on patient-specific motion proved more effective in restoring natural anterior guidance. The anterior guidance of prostheses designed using a virtual articulator was influenced by occlusal plane position.
CLINICAL SIGNIFICANCE
The utilization of a jaw motion tracer facilitated the transfer of personalized occlusal plane positions and recorded jaw motion, which can be integrated into the digital prosthetic workflow for virtual occlusion adjustment. Occlusal design based on patient-specific motion more effectively restored lingual guidance of maxillary anterior crowns.
Topics: Humans; Jaw Relation Record; Dental Occlusion; Incisor; Maxilla; Dental Articulators; Computer-Aided Design
PubMed: 38199326
DOI: 10.1016/j.jdent.2024.104833