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Indian Journal of Dental Research :... Oct 2023To compare and evaluate the occlusal variability/discrepancy recorded using qualitative (articulating paper) and quantitative (T-scan) techniques in partially edentulous... (Comparative Study)
Comparative Study Clinical Trial
Comparative Evaluation of Implant-Protected Occlusion in Partially Edentulous Fixed Restoration Using Qualitative and Quantitative Assessment - A Prospective Clinical Trial.
OBJECTIVES
To compare and evaluate the occlusal variability/discrepancy recorded using qualitative (articulating paper) and quantitative (T-scan) techniques in partially edentulous implant-supported restorations.
MATERIALS AND METHODS
A total of 20 patients in the age group of 25-61 yrs participated in this study. All the patients had more than one tooth replaced with implant-supported prosthesis. After three months of restoration, occlusion reevaluated was carried out using qualitative (articulating paper) and quantitative (T-scan). T-scan data were used to measure implant occlusion time, occlusion time, and the relative occlusal force (ROFs) on implant prosthesis. And the data were statistically evaluated.
RESULTS
The T-scan values showed high points on the implants in most of the patients, which could not be evaluated by that of articulating paper outcomes.
CONCLUSION
The occlusal harmony achieved from using qualitative analysis of articulating paper was not supported by the finding of the quantitative analysis (T-scan). Also the T-scan provided the time interval of occlusion of the implant-supported restorations, which would help in better defining the implant-protected occlusal.
CLINICAL RELEVANCE
The T-scan occlusal analysis system provides ROF and time intervals of occlusal contact. This allows accurate occlusal equilibration of implant-supported restoration according to implant protected occlusal concept.
Topics: Humans; Middle Aged; Prospective Studies; Adult; Dental Prosthesis, Implant-Supported; Male; Female; Dental Occlusion; Jaw, Edentulous, Partially; Bite Force; Denture, Partial, Fixed; Dental Implants; Jaw Relation Record
PubMed: 38739819
DOI: 10.4103/ijdr.ijdr_191_23 -
Indian Journal of Dental Research :... Oct 2023Studies comparing the clinical performance of titanium zirconium (Ti-Zr) and titanium (Ti) dental implants subjected to immediate loading in the posterior mandibular... (Randomized Controlled Trial)
Randomized Controlled Trial Comparative Study
BACKGROUND
Studies comparing the clinical performance of titanium zirconium (Ti-Zr) and titanium (Ti) dental implants subjected to immediate loading in the posterior mandibular region where occlusal forces are higher are sparse in the current literature. Hence, the study aimed to evaluate and compare the clinical outcomes of Ti-Zr and Ti dental implants under immediate functional loading in the mandibular posterior region.
METHODS
Forty participants fulfilling the predetermined selection criteria were randomly grouped based on dental implant used; Titanium zirconium (Ti-Zr):20, and Titanium (Ti):20. Dental implants were placed through a standard full-thickness mucoperiosteal flap approach and loaded immediately fulfilling the principle of implant protective occlusion. Clinical parameters including crestal bone loss (CBL), modified plaque index (MPI), probing depth (PD) and modified sulcular bleeding index (MSBI) were measured at baseline and follow-up visits (4, 8, and 12 months). Obtained data were compared with standard tests such as the t-test, Chi-square test, and Mann-Whitney U test.
RESULTS
On intergroup comparison, CBL was more in the Ti-Zr group as compared to the Ti group at 4 months (0.72 ± 0.16 mm versus 0.70 ± 0.13 mm), but it was less at 8 months (1.08 ± 0.16 mm versus 1.13 ± 0.13 mm) and 12 months (1.19 ± 0.17 mm versus 1.24 ± 0.12 mm) but the difference was not statistically significant (P > 0.05). Mann-Whitney test also revealed no statistically significant difference in MPI, PD and MSBI at 4 months, 8 months and 12 months recall (P > 0.05).
CONCLUSIONS
CBL and periodontal parameters of Ti-Zr dental implants were found similar to Ti dental implants under immediate loading in the posterior mandibular region. However, further studies are needed to determine its long-term efficacy and cost-effectiveness.
Topics: Humans; Titanium; Zirconium; Male; Female; Adult; Mandible; Dental Implants; Treatment Outcome; Immediate Dental Implant Loading; Middle Aged; Periodontal Index; Alveolar Bone Loss; Young Adult
PubMed: 38739813
DOI: 10.4103/ijdr.ijdr_313_23 -
Oral Diseases May 2024This study aims to evaluate food impaction on three-dimensional (3D) printed models with periodontal ligament simulation.
OBJECTIVE
This study aims to evaluate food impaction on three-dimensional (3D) printed models with periodontal ligament simulation.
MATERIALS AND METHODS
Based on a commercial typodont pair, 3D maxillary and mandibular models were created with no teeth and with tooth sockets that were 1 mm wider than the original ones from 24 to 27 or 34 to 37 for periodontal ligament simulation with vinyl polysiloxane impression material. In total, 35 pairs of 7 combinations, including maxillary/mandibular typodonts in occlusion with maxillary/mandibular 3D models with/without a distal gap of canines on 3D models (tooth 23 or 33) were mounted on hinge articulators and divided into seven groups (n = 5). Each sample experienced the same manual chewing simulation on a customized device. The proximal surfaces were photographed to measure the percentage of food impaction area using ImageJ software.
RESULTS
Group with fixed maxillary and mandibular teeth showed more food impaction than other groups with significant differences in the average of maxilla and the average of all proximal areas.
CONCLUSION
The flexibility of the periodontal ligament and the degree of freedom of the teeth in their sockets may contribute to the extent of food impaction in proximal spaces.
PubMed: 38735836
DOI: 10.1111/odi.14989 -
Journal of Dentistry Jul 2024This systematic review evaluated the occlusal changes after loading with implant-supported single crowns. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This systematic review evaluated the occlusal changes after loading with implant-supported single crowns.
SOURCES
An electronic literature search was conducted in PubMed, Embase and Cochrane library for randomized (RCTs) or non-randomized controlled clinical trials (CCTs), with a minimum of 10 patients.
STUDY SELECTION
Studies reporting the occlusal force changes on implant-supported single crowns - with natural teeth as antagonist - measured at baseline and after loading periods were included. 4 CCTs including 133 ISCs in posterior sites were included for meta-analysis. All analyzed ISCs had no contact at a light bite and a light contact at a heavy bite in MIP at loading (baseline).
DATA
The relative occlusal forces (ROFs) of each implant-supported single crown (ISC) or control tooth (CT) were extracted. ROFs were defined as percentage of the total occlusal force of the entire dentition at maximum intercuspal position (MIP). A meta-analysis was conducted to compare the ROF changes at different follow-up periods and the weighted mean differences in ROF between ISCs and CTs were pooled and analyzed. The amount of change in ROF was significantly lower in 6 to 12 months after loading comparing the follow-up period between baseline and 6 month (p < 0.05). At baseline and 3-month follow-up, CTs presented significant higher ROF than ISCs (p < 0.05), while no significant difference was found after half year following.
CONCLUSIONS
This study showed that the ROF changes significantly over time after loading of ISCs. It might prove that the occlusal concept defined at the time of prosthetic delivery changes or adapts naturally over time.
CLINICAL SIGNIFICANCE
The function of specific implant occlusal concept (no contact at a light bite and a light contact at a heavy bite in MIP) is limited over time and careful monitoring and occlusal adjustments should be recommendable during the first-year follow-up.
Topics: Humans; Crowns; Bite Force; Dental Prosthesis, Implant-Supported; Dental Implants, Single-Tooth; Follow-Up Studies; Dental Occlusion
PubMed: 38734300
DOI: 10.1016/j.jdent.2024.105000 -
European Journal of Orthodontics Jun 2024The biomechanics in achieving molar distalization may differ between fixed appliances and clear aligners in the control of tooth movement. The objective of this study... (Comparative Study)
Comparative Study
OBJECTIVES
The biomechanics in achieving molar distalization may differ between fixed appliances and clear aligners in the control of tooth movement. The objective of this study was to compare the treatment effects between clear aligners (CA) and fixed appliances (FA) in patients treated with miniscrew-assisted molar distalization.
METHODS
The sample consisted of 46 subjects with mild-to-moderate crowding. A total of 22 patients treated with clear aligners (age, 25.66 ± 6.11 years old) and 24 patients treated with fixed appliances (age, 24.04 ± 4.95 years old) for miniscrew-assisted molar distalization were included in this study. The dental and skeletal changes were evaluated by the pre- and post-treatment lateral cephalograms.
RESULTS
Significant changes were found with the vertical variables SN-OP angle (2.24 ± 3.22°, P < .05) and SN-MP angle (0.73 ± 1.15°, P < .05) for the FA group when compared with the CA group (SN-OP angle 0.41 ± 2.26° and SN-MP angle -0.21 ± 1.38°, P > .05). Both treatment groups achieved a 2-3 mm. molar distalization with significant intrusion of the upper molars. The CA group showed significantly less distal tipping of molars (U6^PP angle -2.29 ± 3.29° and L6^MP angle -2.92 ± 2.49°, P < .05) compared to the FA group (-5.24 ± 4.28° and -5.53 ± 5.03°, P < .05). In addition, significant retraction and lingual inclination of the upper and lower incisors were found in both groups.
LIMITATIONS
The changes of tooth position were evaluated by 2D lateral cephalograms, not 3D measurements.
CONCLUSIONS
Compared to fixed appliances, clear aligners seemed to have better control of vertical dimension and distal tipping of molars in patients treated with miniscrew-assisted molar distalization.
Topics: Humans; Tooth Movement Techniques; Molar; Male; Female; Orthodontic Appliances, Fixed; Bone Screws; Cephalometry; Adult; Orthodontic Anchorage Procedures; Young Adult; Orthodontic Appliance Design; Malocclusion; Treatment Outcome; Maxilla; Mandible; Orthodontic Appliances, Removable; Incisor; Vertical Dimension
PubMed: 38733349
DOI: 10.1093/ejo/cjae021 -
BMC Oral Health May 2024With the development and utilization of three-dimensional (3D) intraoral scanning (IOS) technology, the morphological characteristics of teeth were quantitatively...
BACKGROUND
With the development and utilization of three-dimensional (3D) intraoral scanning (IOS) technology, the morphological characteristics of teeth were quantitatively assessed. In this research, we aimed to explore the prevalence of dental caries in relation to each measurable morphological indicator of the tooth body via 3D intraoral scanning techniques.
METHODS
A hospital-based single-centre study was conducted at our hospital from Dec. 2021 to Apr. 2023. A total of 53 patients were involved in the study, providing complete morphological data for 79 teeth. Each patient completed an oral hygiene routine questionnaire and underwent examination by an experienced dentist to evaluate caries conditions before undergoing 3D intraoral scanning to obtain a digital dental model. Geomagic Studio 2014 was used to extract oral morphological data from the models. The acquired data were entered, cleaned and edited using Excel 2016 and subsequently exported to SPSS version 25.0 for analysis. Chi-square analysis and logistic regression analyses were employed to test the associations.
RESULTS
Among the participants, 33 (61.1%) were female, with a mean age of 26.52 ± 10.83 years. Significant associations were found between dental caries and the vertical distance between the distal tip and the gum (OR 14.02; 95% CI 1.80-109.07; P = 0.012), the distal lateral horizontal distance of occlusion (OR 0.40; 95% CI 0.18-0.90; P = 0.026), and the mesial horizontal distance of occlusion (OR 2.20; 95% CI 1.12-4.31; P = 0.021). The Hosmer-Lemeshow test indicated a P value of 0.33.
CONCLUSIONS
The vertical distance between the distal tip and the gum, the distal lateral horizontal distance of the occlusion and the mesial horizontal distance of the occlusion were the influencing factors for dental caries (identified as independent risk factors). We hypothesize that these factors may be associated with the physiological curvature of teeth and the role of chewing grooves in plaque formation over time. However, further studies involving larger population samples and more detailed age stratification are still needed.
Topics: Humans; Dental Caries; Female; Male; Imaging, Three-Dimensional; Adult; Tooth Crown; Adolescent
PubMed: 38730377
DOI: 10.1186/s12903-024-04292-9 -
Biomechanics of biting in loggerhead shrikes: jaw-closing force, velocity and an argument for power.The Journal of Experimental Biology Apr 2024Differences in the physical and behavioral attributes of prey are likely to impose disparate demands of force and speed on the jaws of a predator. Because of...
Differences in the physical and behavioral attributes of prey are likely to impose disparate demands of force and speed on the jaws of a predator. Because of biomechanical trade-offs between force and speed, this presents an interesting conundrum for predators of diverse prey types. Loggerhead shrikes (Lanius ludovicianus) are medium-sized (∼50 g) passeriform birds that dispatch and feed on a variety of arthropod and vertebrate prey, primarily using their beaks. We used high-speed video of shrikes biting a force transducer in lateral view to obtain corresponding measurements of bite force, upper and lower bill linear and angular displacements, and velocities. Our results show that upper bill depression (about the craniofacial hinge) is more highly correlated with bite force, whereas lower bill elevation is more highly correlated with jaw-closing velocity. These results suggest that the upper and lower jaws might play different roles for generating force and speed (respectively) in these and perhaps other birds as well. We hypothesize that a division of labor between the jaws may allow shrikes to capitalize on elements of force and speed without compromising performance. As expected on theoretical grounds, bite force trades-off against jaw-closing velocity during the act of biting, although peak bite force and jaw-closing velocity across individual shrikes show no clear signs of a force-velocity trade-off. As a result, shrikes appear to bite with jaw-closing velocities and forces that maximize biting power, which may be selectively advantageous for predators of diverse prey that require both jaw-closing force and speed.
Topics: Animals; Biomechanical Phenomena; Jaw; Bite Force; Passeriformes; Predatory Behavior; Beak; Video Recording
PubMed: 38726757
DOI: 10.1242/jeb.246555 -
Cureus Apr 2024In order to effectively address challenges related to anterior teeth restoration and achieve natural-looking results, considerations such as shape, size, gingival...
In order to effectively address challenges related to anterior teeth restoration and achieve natural-looking results, considerations such as shape, size, gingival contour, and color are crucial. Due to an increasing desire for visually appealing alternatives that are free of metal, materials such as dental zirconia have become popular because of their superior aesthetics and mechanical characteristics. This case report presents clinical insights into anterior teeth rehabilitation with the use of layered zirconia fixed dental prostheses. It delves into the experiences associated with zirconia dental restorations on both endodontically treated and vital abutments, aiming to discern how various factors influence treatment outcomes. Beginning with the design of the restoration, its intricacies significantly impact its fit, strength, and overall durability. Moreover, the composition of zirconia used plays a pivotal role, as different formulations offer varying degrees of mechanical properties, influencing factors such as resilience and wear resistance. The shade selection is also scrutinized, as it directly affects the restoration's aesthetic integration with surrounding natural teeth, contributing to a more harmonious smile. Furthermore, the layering technique employed, particularly when additional porcelain or ceramic layers are applied, is essential for both cosmetic enhancement and structural integrity. Lastly, considerations of occlusion are paramount, ensuring proper alignment and contact between teeth to prevent premature wear and discomfort. By exploring these facets in zirconia restorations across different abutment types, this inquiry seeks to illuminate best practices for achieving favorable treatment outcomes in dental restoration procedures. The choice of zirconia composition, framework design, and shade must be carefully tailored to suit the characteristics of each individual abutment. This emphasizes the significance of adopting a tailored approach to tackle the distinct challenges posed by every clinical scenario. The manuscript provides detailed observations from a clinical case involving the restoration of anterior teeth utilizing monolithic zirconia-fixed dental prostheses. Through a combination of root canal treatment and composite buildup, successful restoration was achieved, with meticulous attention paid to aesthetic considerations. The utilization of computer-aided designing/computer-aided manufacturing (CAD/CAM) technology in crafting zirconia restorations ensured precise fit and superior biocompatibility, contributing to the overall success of the treatment. The study underscores the importance of personalized treatment strategies in achieving optimal outcomes in anterior teeth restoration, emphasizing the need for careful consideration of various factors such as design, composition, and shade selection. Overall, the findings shed light on the potential of zirconia-based restorations in addressing the unique challenges associated with anterior teeth rehabilitation, offering valuable insights for dental practitioners striving to deliver aesthetically pleasing and functionally sound outcomes for their patients.
PubMed: 38725786
DOI: 10.7759/cureus.57889 -
Acta Neurochirurgica May 2024A 40-year-old female with a history of ischemic moyamoya disease treated with indirect revascularization at ages 12 and 25 years presented with a sudden severe...
A 40-year-old female with a history of ischemic moyamoya disease treated with indirect revascularization at ages 12 and 25 years presented with a sudden severe headache. Imaging studies revealed focal parenchymal hemorrhage and acute subdural hematoma, confirming a microaneurysm formed on the postoperative transosseous vascular network as the source of bleeding. Conservative management was performed, and no hemorrhage recurred during the 6-month follow-up period. Interestingly, follow-up imaging revealed spontaneous occlusion of the microaneurysm. However, due to the rarity of this presentation, the efficacy of conservative treatment remains unclear. Further research on similar cases is warranted.
Topics: Humans; Moyamoya Disease; Female; Adult; Cerebral Revascularization; Aneurysm, Ruptured; Postoperative Complications; Intracranial Aneurysm; Anastomosis, Surgical
PubMed: 38719974
DOI: 10.1007/s00701-024-06102-1 -
Journal of Dentistry Jul 2024This preliminary study aimed to clinically assess the precision of a novel optical jaw tracking system (JTS) in registering mandibular movements (MMs) of protrusion and...
OBJECTIVES
This preliminary study aimed to clinically assess the precision of a novel optical jaw tracking system (JTS) in registering mandibular movements (MMs) of protrusion and mediotrusion.
METHODS
Twenty healthy participants underwent recordings using Cyclops JTS (Itaka Way Med) for functional MMs of protrusion and laterotrusion by two trained clinicians. Each subject performed five registrations at different times according to a standardized pattern within one-month period. The angulations of protrusive and mediotrusive functional paths within the first 2 mm from the maximal intercuspal position (MIP) were calculated for each trace, using a data software for angle measurements. Descriptive statistics were used to assess the repeatability of the recordings for each participant and MM. Additionally, inferential statistics were carried out on standard deviation values obtained (α=0.05).
RESULTS
The overall precision for all the patients was 7.07±3.37° for the protrusion angle, 5.24±2.24° for right laterotrusion and 5.14±3.06° for left laterotrusion angles. The protrusion angle ranged from 3.08° to 13.57°, while the right and left laterotrusion ranged from 1.82° to 9.42° and from 1.58° to 10.59°, respectively. No statistically significant differences were observed between different functional MM types and gender (p > 0.05).
CONCLUSIONS
Recordings functional MMs of mediotrusion and protrusion using Cyclops JTS showed consistent repeatability, regardless of gender and functional MM type. The results revealed non-negligible variations that may be due to the patients' abilities to precisely reproduce jaw movements or to the operator's ability to consistently connect the kinesiograph.
CLINICAL SIGNIFICANCE
Capturing functional MMs digitally and importing the data into dental CAD software is essential for virtual waxing in prosthetic rehabilitations to design a functionalized adapted occlusion. Establishing the repeatability of MM recordings by a JTS is a crucial step in better understanding this novel JTS in the market. This process could facilitate the interpretation of cusp angles, aid in CAD dynamic technical modeling, and enhance clinical data communication between clinicians and technicians in a modern workflow.
Topics: Humans; Male; Female; Mandible; Adult; Movement; Reproducibility of Results; Young Adult; Jaw Relation Record; Software
PubMed: 38719134
DOI: 10.1016/j.jdent.2024.105047