-
Cureus May 2024Accurate occlusal vertical dimension (OVD) establishment is an essential component of prosthodontic treatment. No accurate approach exists to determine the appropriate...
OBJECTIVES
Accurate occlusal vertical dimension (OVD) establishment is an essential component of prosthodontic treatment. No accurate approach exists to determine the appropriate OVD for patients without posterior teeth. This study aimed to correlate the accuracy of the nose-to-chin distance with various facial measurements and thumb length in dentulous and edentulous Saudi patients.
MATERIALS AND METHODS
The participants comprised 100 fully dentulous Saudi male dental students aged 20-30 years (group 1) and 20 completely edentulous patients aged 60-70 years (group 2). We evaluated the correlations between the OVD (nose-to-chin distance) and the distance from the pupil to the corner of the mouth, the vertical length at midline of the nose (from subnasion to glabella), the distance from the outer canthus of one eye to the inner canthus of the other, twice the distance between the inner canthi, and the distance from the thumb tip to the index fingertip.
STATISTICAL ANALYSIS
Spearman's correlation and regression analysis were performed to analyze and assess the correlations between the clinically measured nose-to-chin distance and other parameters, with significance set at 0.05.
RESULTS
In edentulous patients, the results showed a significant, strong, positive correlation between the nose-to-chin distance and the distance between the pupil and the mouth corner. In dentate subjects, a significant, strong, positive association was found between the nose-to-chin distance and the distance from the outer canthus of one eye to the inner canthus of the other. The linear regression analysis revealed that the distance between the pupil and the mouth corner in edentulous patients significantly predicted the OVD.
CONCLUSIONS
In both groups, the distance from the outer canthus of one eye to the inner canthus of the other and the distance from the pupil to the mouth corner were reliable and accurate for OVD measurements. These could be considered appropriate methods for OVD determination during full-mouth rehabilitation.
PubMed: 38756708
DOI: 10.7759/cureus.60443 -
BMC Oral Health May 2024Prefabricated myofunctional appliance can guide tooth eruption, improve dentition alignment, correct myofunctional disorders and harmful oral habits. However, its...
BACKGROUND
Prefabricated myofunctional appliance can guide tooth eruption, improve dentition alignment, correct myofunctional disorders and harmful oral habits. However, its application to skeletal discrepancy may result in unsatisfactory tooth inclination. This study aimed to construct a novel appliance with overjet design to avoid this side effect and investigated its shape and mechanical changes under occlusion using three-dimensional finite element method.
METHODS
We established three samples of prefabricated myofunctional appliances. The first one was edge to edge without overjet, and the outer shield of both jaws were flattened. The second one was 3 mm overjet with stepped the outer shield. The last one was 3 mm overjet, and the outer shield of both jaws were flatted, which meant the front wall of lower jaw was strengthened with bumper, termed as lower bumper. A complete dentition model was applied to the study. 150 N occlusal force was applied to each type of appliance and the deformation displacement and the changes in stress was recorded.
RESULTS
The deformation was significant in the incisors regions, especially in the vertical and lateral dimensions. The maximum displacements of 3 mm overjet with step shield group were 7.08 mm (vertical), 3.99 mm (lateral), and 2.90 mm (sagittal), while it decreased to 3.92 mm(vertical), 1.94 mm (lateral), and 1.55 mm (sagittal) in overjet with bumper group. Moreover, the upper molar regions exhibited higher vertical and sagittal displacement in 3 mm overjet with step shield group, which were 3.03 mm (vertical) and 1.99 mm (sagittal), and the bumper design could decrease the maximum displacement to 1.72 mm (vertical) and 0.72 mm (sagittal). In addition, the Von Mises stress of appliances was analyzed, and results indicated that 3 mm overjet with step shield generated higher stress than other groups, with the maximum Von Mises stress was 0.9387 MP, which were 0.5858 and 0.5657 MP in edge to edge group and 3 mm overjet with lower bumper group, respectively.
CONCLUSION
The prefabricated myofunctional appliances may cause deformation during occlusion. Compared to step shield group, the application of lower bumper exhibited better resistance to occlusal force.
Topics: Finite Element Analysis; Humans; Orthodontic Appliance Design; Myofunctional Therapy; Bite Force; Imaging, Three-Dimensional; Overbite; Stress, Mechanical; Mandible; Incisor; Biomechanical Phenomena
PubMed: 38745284
DOI: 10.1186/s12903-024-04325-3 -
Head & Face Medicine May 2024In this study, we sought to quantify the influence of vertical control assisted by a temporary anchorage device (TAD) on orthodontic treatment efficacy for skeletal...
BACKGROUND
In this study, we sought to quantify the influence of vertical control assisted by a temporary anchorage device (TAD) on orthodontic treatment efficacy for skeletal class II patients with a hyperdivergent facial type and probe into the critical factors of profile improvement.
METHODS
A total of 36 adult patients with skeletal class II and a hyperdivergent facial type were included in this retrospective case-control study. To exclude the effect of sagittal anchorage reinforcement, the patients were divided into two groups: a maxillary maximum anchorage (MMA) group (N = 17), in which TADs were only used to help with anterior tooth retraction, and the MMA with vertical control (MMA + VC) group (N = 19), for which TADs were also used to intrude the maxillary molars and incisors. The treatment outcome was evaluated using dental, skeletal, and soft-tissue-related parameters via a cephalometric analysis and cast superimposition.
RESULTS
A significant decrease in ANB (P < 0.05 for both groups), the retraction and uprighting of the maxillary and mandibular incisors, and the retraction of protruded upper and lower lips were observed in both groups. Moreover, a significant intrusion of the maxillary molars was observed via the cephalometric analysis (- 1.56 ± 1.52 mm, P < 0.05) and cast superimposition (- 2.25 ± 1.03 mm, P < 0.05) of the MMA + VC group but not the MMA group, which resulted in a remarkable decrease in the mandibular plane angle (- 1.82 ± 1.38°, P < 0.05). The Z angle (15.25 ± 5.30°, P < 0.05) and Chin thickness (- 0.97 ± 0.45°, P < 0.05) also improved dramatically in the MMA + VC group, indicating a better profile and a relaxed mentalis. Multivariate regression showed that the improvement in the soft tissue was closely related to the counterclockwise rotation of the mandible plane (P < 0.05).
CONCLUSIONS
TAD-assisted vertical control can achieve intrusion of approximately 2 mm for the upper first molars and induce mandibular counterclockwise rotation of approximately 1.8°. Moreover, it is especially important for patients without sufficient retraction of the upper incisors or a satisfactory chin shape.
Topics: Humans; Malocclusion, Angle Class II; Female; Male; Retrospective Studies; Cephalometry; Adult; Case-Control Studies; Young Adult; Treatment Outcome; Orthodontic Anchorage Procedures; Orthodontics, Corrective; Tooth Movement Techniques; Vertical Dimension; Adolescent
PubMed: 38745246
DOI: 10.1186/s13005-024-00432-2 -
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 -
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 -
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 -
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 -
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 -
Journal of Feline Medicine and Surgery May 2024A total of 13 cases of cats with a caudal mandibular fracture treated with a novel surgical technique using the Ramus Anatomical Plate system were reviewed....
CASE SERIES SUMMARY
A total of 13 cases of cats with a caudal mandibular fracture treated with a novel surgical technique using the Ramus Anatomical Plate system were reviewed. Preoperative, immediate postoperative and a minimum of 8 weeks postoperative CT images were required as inclusion criteria. The outcome and complications were determined from clinical data and radiographic follow-up examinations. All cases achieved adequate anatomical reduction, resulting in a functional and atraumatic occlusion postoperatively. No intraoperative complications were reported. Time to voluntary food intake was in the range of 1-25 days. No evidence of disruptions to the implants or screw loosening was observed in the 8-week postoperative CT imaging, with radiographic evidence of complete osseous union in all fractures. The most common postoperative complication was swelling at the surgical site. Two cats had postoperative exophthalmos due to retrobulbar haemorrhage, and one cat exhibited partial wound dehiscence 5 days postoperatively, which resolved with medical management. Longer-term complications included intraoral plate exposure in one cat, which required plate removal 10 months postoperatively.
RELEVANCE AND NOVEL INFORMATION
In this case series, rigid internal fixation of caudal mandibular fractures using the Ramus Anatomical Plate osteosynthesis system was associated with a minimal complication rate, and satisfactory radiographic and clinical outcomes. The reported outcomes of this novel technique are favourable when compared with previous techniques described for the management of these fracture types.
Topics: Cats; Animals; Bone Plates; Fracture Fixation, Internal; Mandibular Fractures; Male; Female; Treatment Outcome; Postoperative Complications; Tomography, X-Ray Computed; Cat Diseases
PubMed: 38717791
DOI: 10.1177/1098612X241243134