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Journal of Prosthodontics : Official... Oct 2023To investigate the effects of the manufacturing technologies on the surface (cameo and intaglio) accuracy (trueness and precision) of computer-aided design and...
PURPOSE
To investigate the effects of the manufacturing technologies on the surface (cameo and intaglio) accuracy (trueness and precision) of computer-aided design and computer-aided manufacturing (CAD-CAM) occlusal splints.
MATERIALS AND METHODS
The digital design of the master occlusal splint was designed in a CAD software program. Six groups (n = 10) were tested in this study, including Group 1 - Milling (Wax), Group 2 - Heat-polymerizing, Group 3 - Milling (M series), Group 4 - Milling (DWX-51/52D), Group 5 - 3D-printing (Cares P30), and Group 6 - 3D-printing (M2). The study samples were placed in a scanning jig fabricated from putty silicone and Type III dental stone. The study samples were then scanned with a laboratory scanner at the intaglio and cameo surfaces, and the scanned files were exported in standard tessellation language (STL) file format. The master occlusal splint STL file, was used as a reference to compare with all scanned samples at the intaglio and cameo surfaces in a surface matching software program. Root mean square (RMS, measured in mm, absolute value) values were calculated by the software for accuracy comparisons. Group means were used as the representation of trueness, and the standard deviation for each group was calculated as a measure of precision. Color maps were recorded to visualize the areas of deviation between study samples and the master occlusal splint file. The data were normalized and transformed to rank scores, and one-way ANOVA was used to test for the differences between the groups. Pairwise comparisons were made between different groups. Fishers least square differences were used to account for the family-wise error rate. A 5% significance level was used for all the tests.
RESULTS
The null hypotheses were rejected. The manufacturing technologies significantly affected the trueness of occlusal splints at both intaglio and cameo surfaces (p < 0.001). At the cameo surfaces, Group 1 - Milling (Wax) (0.03 ± 0.02 mm), Group 3 - Milling (M series) (0.04 ± 0.01 mm), and Group 4 - Milling (DWX-51/52D) (0.04 ± 0.01 mm) had the smallest mean RMS values and highest trueness. Group 3 had the smallest standard deviation and highest precision among all groups (p < 0.001, except p = 0.005 when compared with Group 2). Group 5 had the largest standard deviation and lowest precision among all groups (p < 0.001). At the intaglio surfaces, Group 1 - Milling (Wax) (0.06 ± 0.01 mm) had the smallest RMS values and highest trueness among all groups (p < 0.001), and Group 2 - Heat-polymerizing (0.20 ± 0.03 mm) and Group 5 - 3D-printing (Cares P30) (0.15 ± 0.05 mm) had significantly larger mean RMS and standard deviation values than all other groups (p < 0.001), with lowest trueness and precision. In the color maps, Group 2 - Heat-polymerizing and Group 5 - 3D-printing (Cares P30) showed the most discrepancies with yellow and red (positive discrepancies) in most areas, and Group 1 - Milling (Wax) showed the best and most uniform surface matching with the most area in green.
CONCLUSION
The manufacturing technologies significantly affected the trueness and precision of occlusal splints at both intaglio and cameo surfaces. The 5-axis milling units and industrial-level CLIP 3D-printer could be considered to achieve surface accuracy of occlusal splints.
Topics: Occlusal Splints; Computer-Aided Design; Printing, Three-Dimensional; Software
PubMed: 36227731
DOI: 10.1111/jopr.13610 -
The Journal of Craniofacial Surgery Sep 2023The fracture of mandibular symphysis combined with bilateral condylar fractures often leads to changes in the width of the mandible, which significantly widens the face...
BACKGROUND
The fracture of mandibular symphysis combined with bilateral condylar fractures often leads to changes in the width of the mandible, which significantly widens the face of the child. Therefore, it is necessary to reposition the mandible through accurate adduction.
METHODS
To ensure that the mandible can be accurately repositioned, a 3D printed occlusal splint was used. Bilateral maxillomandibular fixation screws were implanted. The 3D printed occlusal splint was located on the maxillary dentition and fixed to the maxillomandibular fixation screws with wire loops. The reference basis for adduction is to make the mandibular dentition located in the occlusal splint. The absorbable plate was contoured according to the restored model and fixed at the fracture site. The 3D printed occlusal splint was retained in the maxillary dentition for two months.
RESULTS AND DISCUSSION
Postoperative computed tomography showed that the mandible had been adducted according to the preoperative design. Two months of follow-up showed that the child's facial development, mouth opening type, occlusion, and range of motion were good. It is especially suitable for children with mandibular symphyseal fractures accompanied by bilateral condylar fractures.
Topics: Child; Humans; Mandibular Fractures; Occlusal Splints; Treatment Outcome; Mandible; Fractures, Multiple; Printing, Three-Dimensional; Mandibular Condyle; Fracture Fixation, Internal
PubMed: 37236625
DOI: 10.1097/SCS.0000000000009418 -
The Journal of Prosthetic Dentistry Oct 2023Artificial intelligence (AI) models have been developed for different applications, including the automatic design of occlusal devices; however, the design discrepancies...
STATEMENT OF PROBLEM
Artificial intelligence (AI) models have been developed for different applications, including the automatic design of occlusal devices; however, the design discrepancies of an experienced dental laboratory technician and these AI automatic programs remain unknown.
PURPOSE
The purpose of this in vitro study was to compare the overall, intaglio, and occlusal surface discrepancies of the occlusal device designs completed by an experienced dental laboratory technician and two AI automatic design programs.
MATERIAL AND METHODS
Virtually articulated maxillary and mandibular diagnostic casts were obtained in a standard tessellation language (STL) file format. Three groups were created depending on the operator or program used to design the occlusal devices: an experienced dental laboratory technician (control group) and two AI programs, namely Medit Splints from Medit (Medit group) and Automate from 3Shape A/S (3Shape group) (n=10). To minimize the discrepancies in the parameter designs among the groups tested, the same printing material and design parameters were selected. In the control group, the dental laboratory technician imported the articulated scans into a dental design program (DentalCAD) and designed a maxillary occlusal device. The occlusal device designs were exported in STL format. In the Medit and 3Shape groups, the diagnostic casts were imported into the respective AI programs. The AI programs automatically designed the occlusal device without any further operator intervention. The occlusal device designs were exported in STL format. Among the 10 occlusal designs of the control group, a random design (shuffle deck of cards) was used as a reference file to calculate the overall, intaglio, and occlusal discrepancies in the specimens of the AI groups by using a program (Medit Design). The root mean square (RMS) error was calculated. Kruskal-Wallis, and post hoc Dwass-Steel-Critchlow-Fligner pairwise comparison tests were used to analyze the trueness of the data. The Levene test was used to assess the precision data (α=.05).
RESULTS
Significant overall (P<.001), intaglio (P<.001), and occlusal RMS median value (P<.001) discrepancies were found among the groups. Significant overall RMS median discrepancies were observed between the control and the Medit groups (P<.001) and the control and 3Shape groups (P<.001). Additionally, significant intaglio RMS median discrepancies were found between the control and the Medit groups (P<.001), the Medit and 3Shape groups (P<.001), and the control and 3Shape groups (P=.008). Lastly, significant occlusal RMS median discrepancies were found between the control and the 3Shape groups (P<.001) and the Medit and 3Shape groups (P<.001). The AI-based software programs tested were able to automatically design occlusal devices with less than a 100-µm trueness discrepancy compared with the dental laboratory technician. The Levene test revealed significant overall (P<.001), intaglio (P<.001), and occlusal (P<.001) precision among the groups tested.
CONCLUSIONS
The use of a dental laboratory technique influenced the overall, intaglio, and occlusal trueness of the occlusal device designs obtained. No differences were observed in the precision of occlusal device designs acquired among the groups tested.
PubMed: 37798183
DOI: 10.1016/j.prosdent.2023.08.015 -
European Journal of Oral Sciences Apr 2024This systematic review answers the question: "Does occlusal appliance use influence masticatory muscle function of dentate individuals with sleep bruxism?". The... (Meta-Analysis)
Meta-Analysis Review
This systematic review answers the question: "Does occlusal appliance use influence masticatory muscle function of dentate individuals with sleep bruxism?". The literature search included six databases, grey literature, and manual search for articles. Randomized and non-randomized clinical trials were included comparing muscle function of sleep bruxers before and after receiving occlusal appliances. Risk of bias was assessed with risk of bias assessment for randomized and non-randomized clinical trials tool. Twelve studies, three represent randomized clinical trials, were included. Risk of bias was considered low, moderate, or serious. Meta-analyses indicated that soft and hard appliances did not influence muscle activity and bite force of bruxers. Qualitative analysis showed that occlusal appliance use did not influence masticatory performance and muscle volume. However, it was effective in reducing tongue force. Certainty of evidence was considered very low for muscle activity when evaluated with hard appliances, and for bite force evaluated with both appliance materials. Low certainty of evidence was observed for muscle activity with soft appliances. Based on the findings of this meta-analysis, occlusal appliances do not affect masticatory muscle function of sleep bruxers. Regardless of appliance material, the activity of masseter and temporal, and bite force of sleep bruxers was not influenced.
Topics: Humans; Sleep Bruxism; Masticatory Muscles; Masseter Muscle; Occlusal Splints; Sleep
PubMed: 38421263
DOI: 10.1111/eos.12979 -
Journal of Oral Rehabilitation May 2024Single nucleotide polymorphisms (SNPs) may influence pain susceptibility and impact treatment response in pain-related temporomandibular disorders (TMDp).
BACKGROUND
Single nucleotide polymorphisms (SNPs) may influence pain susceptibility and impact treatment response in pain-related temporomandibular disorders (TMDp).
OBJECTIVE
Explore the role of COMT (rs4646310, rs6269, rs4818, rs4680) and OPRM1 (rs1799971) genotypes in regulating treatment response.
METHODS
Sixty TMDp patients (55 females and 5 males), diagnosed with the Diagnostic Criteria for TMD (DC/TMD), underwent standardised treatment (information and education, home physical therapy, occlusal splint) for 6 months. Treatment outcomes included: pain intensity, pain-free mouth opening, jaw functional limitation, depression, and anxiety. Genotyping for COMT and OPRM1 SNPs was performed using DNA from buccal mucosa swabs and TaqMan assays. Statistical analysis was carried out to compare the changes in treatment outcomes and the influence of genotypes on treatment response.
RESULTS
Significantly less pain reduction was observed in minor allele carriers of rs4646310, and rs4680 compared to dominant homozygous (p < .025). Minor allele carriers of rs1799971 and rs4646310 demonstrated worsening in pain-free mouth opening while dominant homozygous exhibited improvement (p < .025). Significantly less anxiety reduction was observed in minor allele carriers of rs4646310 compared to dominant homozygous (p = .003). Of the all variables assessed in the regression model, carrying a minor allele of rs1799971 predicted a poorer treatment response considering pain-free mouth opening while carrying a minor allele of rs4646310 predicted less pain and less anxiety reduction.
CONCLUSION
Our findings indicate that certain SNP variants of the COMT and OPRM1 genes were associated with poorer treatment response and may therefore play a significant role in the classification of TMDp patients. Also, assessment of patient genotype could potentially aid in predicting treatment response.
PubMed: 38725226
DOI: 10.1111/joor.13730 -
The International Journal of... Sep 2023To compare the accuracy of occlusal stabilization appliances fabricated by digital workflows to those fabricated by conventional workflows.
PURPOSE
To compare the accuracy of occlusal stabilization appliances fabricated by digital workflows to those fabricated by conventional workflows.
MATERIALS AND METHODS
In total, 10 volunteers were recruited in this single-blinded crossover study. All volunteers received two types of occlusal stabilization appliances: a digital additively manufactured stabilization splint (DS) and a conventionally fabricated splint (CS). The accuracy was assessed using a 4-point rating scale addressing two aspects of the occlusal appliances: occlusal contact and basic performance. In addition, silicone impression materials were used to assess the gap between the appliance and the maxillary arch to ensure an accurate fit. Differences were quantitatively assessed with Mann-Whitney U test and independent-sample t test.
RESULTS
The occlusal contact rating of DS (15.90 ± 1.73) was significantly higher than that of CS (14.10 ± 1.10, P < .05). The basic performance rating of DS (8.70 ± 0.48) was also significantly higher than that of CS (7.20 ± 0.92. P < .05). Quantitative evaluation of fit accuracy revealed a statistically significant difference (P < .05), with DS (636.29 ± 268.51 μm) being superior to CS (704.2 ± 306.05 μm).
CONCLUSION
The stabilization splints fabricated with a digital workflow showed better accuracy than the conventionally fabricated splints in terms of occlusal contact, basic performance, and fit accuracy. Because this is a pilot study, formal trials with a completely digital fabrication workflow will be conducted in the future.
Topics: Humans; Pilot Projects; Workflow; Cross-Over Studies; Dental Impression Materials; Silicones
PubMed: 37699192
DOI: 10.11607/ijp.7947 -
BMC Oral Health Mar 2024Overerupted maxillary molars is common in adults, which can lead to insufficient intermaxillary vertical space ,great difficulty in prosthetic reconstruction ,and cause...
BACKGROUND
Overerupted maxillary molars is common in adults, which can lead to insufficient intermaxillary vertical space ,great difficulty in prosthetic reconstruction ,and cause occlusal interference in movements.To reconstruct occlusal function, it is necessary to prepare enough space for prostheses. The aim of the present study was to evaluate the effect of space-adjustment occlusal splint on overerupted maxillary molars by clinical and electromyographic signals analysis.
METHODS
Eighteen patients with overerupted maxillary molars were selected to wear space-adjustment occlusal splint suppressing overerupted maxillary molars for three months. Satisfaction was assessed by 5-point Likert; intermaxillary vertical space and the teeth transportation distance were measured in models; clinical periodontal status were evaluated by periodontal probing depth (PPT) and bleeding index (BI); electromyographic recordings of the masseter and anterior temporal muscles were monitored by Cranio-Mandibular K7 Evaluation System.
RESULTS
All the patients were satisfied with the treatment effect (Likert scale ≧ 4). The intermaxillary space in edentulous areas after treatment showed statistically significant increasing when compared with those before treatment. PPT and BI showed no significant difference. No statistically significant differences were found in electromyographic activity of anterior temporal muscles, while a reduction of muscle activity in masseter in the contralateral side were detected in post-treatment evaluations compared with pre-treatment at mandibular rest position.
CONCLUSIONS
Space-adjustment occlusal splint is an efficient treatment option on overerupted maxillary molars by intruding the maxillary molar to obtain adequate intermaxillary space for prostheses.
Topics: Adult; Humans; Splints; Molar; Masseter Muscle; Temporal Muscle; Occlusal Splints; Electromyography
PubMed: 38431564
DOI: 10.1186/s12903-024-04039-6 -
Journal of Oral Rehabilitation Apr 2024The term temporomandibular disorder (TMD) indicates a set of musculoskeletal conditions involving temporomandibular joint (TMJ), masticatory musculature, and related... (Review)
Review
BACKGROUND
The term temporomandibular disorder (TMD) indicates a set of musculoskeletal conditions involving temporomandibular joint (TMJ), masticatory musculature, and related anatomical structures. Pain is the most common clinical manifestation of TMD, and the auditory system might be involved and affected, through tinnitus, dizziness, otalgia and ear fullness sensation.
OBJECTIVES
The aim of this systematic review of randomised controlled trails (RCTs) was to evaluate the efficacy of rehabilitative approaches on otologic symptoms in patients with TMD.
METHODS
PubMed, Scopus and Web of Science were systematically searched from the inception until 8th October 2023 to identify RCTs presenting participants with a diagnosis of TMD associated with otologic signs and symptoms, rehabilitative approaches as interventions, and modification of the otological symptoms as outcome.
RESULTS
Out of 931 papers suitable for title/abstract screening, 627 articles were assessed for eligibility. Five studies were included reporting the efficacy of occlusal splint therapy, low-level laser therapies, and physical therapy in patients diagnosed whit secondary otalgia or tinnitus associated with TMD. No RCTs evaluating other otologic symptoms, ear fullness, dizziness or vertigo were found.
CONCLUSIONS
Results of this systematic review suggested that rehabilitative approaches might be effective in improving secondary otalgia and tinnitus in TMD patients. Thus, further RCTs with a higher level of evidence and more representative samples should be conducted to better understand the effects of TMD therapy on otologic complains.
PubMed: 38685701
DOI: 10.1111/joor.13716 -
BMC Oral Health Apr 2024Temporomandibular disorder (TMD) is a grouping of heterogeneous disorders with multifactorial origins. Stabilization splints (SS) have demonstrated an acceptable...
BACKGROUND
Temporomandibular disorder (TMD) is a grouping of heterogeneous disorders with multifactorial origins. Stabilization splints (SS) have demonstrated an acceptable treatment effect in TMD. The possible changes at the skeletal, dental, and soft tissue levels need to be addressed to evaluate the benefit/risk ratio of this therapeutic procedure. Accordingly, this study aimed to three‑dimensionally evaluate skeletal, dentoalveolar and soft tissue changes after SS treatment for patients with TMD.
METHODS
This retrospective study included 74 adult patients with myofascial and/or intra-articular disorders (25 males and 49 females), with an average age of 22.88 ± 4.8 years, who underwent SS treatment. Pre- and post-treatment Cone beam computed tomography were analysed using Invivo 6.0.3 software. The primary outcome was the vertical skeletal and dentoalveolar changes, while the secondary outcomes were the anteroposterior skeletal, dentoalveolar and soft tissue changes. Paired t-test and Wilcoxon rank sum test were used for statistical analyses.
RESULTS
For the primary outcome; skeletally, there was a significant increase in mandibular plane inclination (difference: 0.82°±1.37), decrease facial height ratio (difference: 0.45%±1.07) and at the dentoalveolar level, the inclination of the functional (FOP-SN, FOP-FH) and bisecting (BOP-SN, BOP-FH) occlusal planes exhibited a significant increase too (difference: 0.38 ± 1.43°, 0.49 ± 1.62°, 0.44 ± 1.29° and 0.41 ± 1.17°, respectively) and also a decrease in the overbite (difference: -0.54 ± 0.83). For the secondary outcomes; there was a significant decrease in mandibular position (SNB) (difference: 1.60 ± 1.36°) and increase in the overjet (difference: 0.93 ± 1.04, p < 0.001) and a significant lower lip retrusion (difference: 0.33 ± 1.01 mm p < 0.01), was observed too.
CONCLUSIONS
SS therapy resulted in significant vertical skeletal and dentoalveolar changes that were manifested mainly by facial height ratio, mandibular and occlusal plane changes, and to a lesser extent, significant anteroposterior skeletal, dentoalveolar, and soft tissue changes in the form of mandibular position, increased overjet and a more retrusive lower lip. These changes should be considered during patients' selection prior to initiating SS therapy.
Topics: Male; Adult; Female; Humans; Adolescent; Young Adult; Maxilla; Retrospective Studies; Splints; Cephalometry; Mandible; Overbite; Malocclusion, Angle Class II; Temporomandibular Joint Disorders; Temporomandibular Joint
PubMed: 38643111
DOI: 10.1186/s12903-024-04260-3 -
Journal of Dentistry Feb 2024This study was conducted to present a completely digital workflow for the fabrication of occlusal stabilization splints using CAD/CAM systems and a digital face bow...
OBJECTIVE
This study was conducted to present a completely digital workflow for the fabrication of occlusal stabilization splints using CAD/CAM systems and a digital face bow based on optical sensor technology.
METHODS
Digital scans of the maxillary and mandibular arches of 20 volunteers were obtained using an intraoral scanner. Jaw relation and mandibular movements were recorded with a digital face bow via optical sensors. The virtual increase of the vertical dimension of occlusion (VDO) was then performed, after which computer-aided design (CAD) of the occlusal stabilization splints was carried out. The corresponding splints were then manufactured using digitally controlled technology.
RESULTS
A completely digital workflow for the manufacturing of occlusal stabilization splints was found to be clinically feasible. The corresponding data analysis revealed high congruence between virtual and physical occlusal contacts on the occlusal splint. Moreover, the appropriate guidance of the anterior teeth area was easily obtainable, and the time for adjusting the occlusion was less.
CONCLUSIONS
This study demonstrated that the fabrication of occlusal stabilization splints using a fully digital workflow is feasible. Compared to traditional impression-based manufacturing, several advantages of digital manufacturing include easy accessibility, time-efficient manufacturing, high-level accuracy in splint quality, and potential to manufacture duplicate splints.
CLINICAL SIGNIFICANCE
The proposed fully digital approach may help young dentists fabricating stable occlusal splints with beneficial curative effects. Meanwhile, it could also improve the production efficiency of stable occlusal splints, saving time for both doctors and patients while reducing labor costs.
Topics: Humans; Occlusal Splints; Splints; Workflow; Mandible; Dental Occlusion; Computer-Aided Design
PubMed: 38157975
DOI: 10.1016/j.jdent.2023.104826