scholarly journals Impact of Orthodontic Brackets on the Intraoral Scan Data Accuracy

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Ji-Man Park ◽  
Shin-Ae Choi ◽  
Ji-Yun Myung ◽  
Youn-Sic Chun ◽  
Minji Kim
Keyword(s):  
Dental Arch ◽  
Maximum Deviation ◽  
Arch Width ◽  
Dental Models ◽  
Digital Measurements ◽  
Standard Values ◽  
Width Measurements ◽  
Scan Data ◽  
Lingual Brackets ◽  
The Impact

This study aims to compare the impact of buccal and lingual brackets on the accuracy of dental arch data acquired by 4 different digital intraoral scanners. Two pairs of dental casts, one with buccal brackets and the other with lingual brackets, were used. Digital measurements of the 3D images were compared to the actual measurements of the dental models, which were considered standard values. The horizontal measurements included intercanine widths and intermolar widths. The Mann–WhitneyUtest was performed for comparisons. iTero® and Trios® both showed high accuracy with relatively small maximum deviation of measurements. iTero showed a significantly higher accuracy in most of the arch width measurements on the buccal bracket model than on the lingual model (P<0.05). Zfx IntraScan® and E4D Dentist® produced maximum deviations of more than 2 mm from both the buccal and the lingual bracket models. After comparing the degree of distortion of the arch on the digital scans with actual measurements of the same models, iTero and Trios proved to be excellent in terms of trueness and precision. Nevertheless, digital intraoral scanners should be used more cautiously in arches with lingual brackets than in those with buccal brackets.

scholarly journals Relationship between Dental Arch Width and Vertical Facial Morphology in Untreated Adults- A Retrospective Study

2021 ◽  
pp. 587-596
Author(s):  
Sameer Narkhede ◽  
Kretikka Sabharwal ◽  
Vivek Soni ◽  
Karthick Shetty ◽  
Sushma Sonawane ◽  
...  
Keyword(s):  
Dental Arch ◽  
Facial Morphology ◽  
Face Shape ◽  
Arch Width ◽  
Mandibular Plane ◽  
Males And Females ◽  
Width Measurements ◽  
Dental Arch Width ◽  
Face Morphology ◽  
Future Growth

Early orthodontic research has focused on the link between face shape and malocclusion. Orthodontic treatment's effectiveness and stability are heavily influenced by a patient's dental and facial anatomy. An orthodontist's knowledge of arch shapes is essential since it affects the patient's treatment and future growth. For this study, the researchers wanted to see if there was a link between vertical face morphology and arch width, and if there was a difference in arch width between males and females. Arch width measurements (in millimetres) were utilised to determine the association. For both males and females, participants with the lowest mandibular plane angle had the widest arch, followed by those with the average mandibular angle and those with the highest.

scholarly journals Aging in the Craniofacial Complex

2008 ◽  
Vol 78 (3) ◽  
pp. 440-444 ◽  
Author(s):  
Marcus M. Dager ◽  
James A. McNamara ◽  
Tiziano Baccetti ◽  
Lorenzo Franchi
Keyword(s):  
Time Effect ◽  
Maxillary Incisor ◽  
Dental Arch ◽  
Mandibular Incisor ◽  
Arch Width ◽  
Irregularity Index ◽  
Curve Of Spee ◽  
Width Measurements ◽  
Sixth Decade ◽  
Craniofacial Complex

Abstract Objective: To describe the dental arch changes occurring after adolescence through the sixth decade of life. Materials and Methods: Longitudinal dental casts from 40 patients (20 male and 20 female) were digitized and analyzed. Measurements were recorded after the presumed cessation of circumpubertal growth (T1), at approximately 47 years of age (T2), and at least one decade later (T3) were compared. Results: The majority of the measurements were found to have a significant time effect, demonstrating at least some level of change throughout the aging process (T1–T3). Exceptions to this observation were the posterior maxillary arch width measurements, mandibular intermolar and interpremolar (as measured at the second premolars) widths, the maxillary incisor irregularity index, overjet, overbite, and curve of Spee. The T1–T3 changes reflected for the most part the T1– T2 changes, while the T2–T3 changes affected overall modifications only for the mandibular intercanine width and maxillary depth, as measured at the second premolars. All changes reflected a decrease in arch width, depth, and perimeter, with a significant increase in the mandibular incisor irregularity index. Conclusions: The dental arches continue to change and adapt throughout life and into the sixth decade, though the degree of change decreases with time.

scholarly journals An Evaluation of Buccal Shield Treatment

2007 ◽  
Vol 77 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Kambiz Moin ◽  
Samir E. Bishara
Keyword(s):  
Treatment Time ◽  
Statistical Tests ◽  
Normal Growth ◽  
Mixed Dentition ◽  
Dental Arch ◽  
Arch Width ◽  
Bodily Movement ◽  
Age Related ◽  
Significant Difference ◽  
Width Measurements

Abstract Objective: To evaluate the short-term effects of the buccal shield modification of the lip-bumper design and on various mandibular dental arch parameters and to determine whether the changes in arch widths are due to the tipping or bodily movements of the teeth involved. Materials and Methods: This study included 45 consecutively treated patients (29 girls and 16 boys) from a private orthodontic practice. Student's and paired t-tests were used to test the null hypothesis of no change over time for the various measurements. Linear regression analyses were used to determine whether treatment time was a significant predictor of arch width expansion. Significance for all statistical tests was predetermined at P ≤ .05. Results: Student's t-test results indicated the presence of a significant (P &lt; .0001) increase in all the arch parameters measured. The greatest mean expansion was observed at the first (5.0 ± 2.2 mm) and second (3.4 ± 2.2 mm) premolar width measurements. The changes in arch width parameters were significantly (P &lt; .0001) greater than the normal age-related changes in the corresponding parameters. There was no significant difference between arch width expansion of the occlusal vs gingival levels, indicating a bodily and not tipping movement. Only 30% of the lower incisors demonstrated an increase in their proclination beyond normal values. Conclusion: When using the buccal shield appliance, the mandibular arch width parameters can be expanded in the mixed dentition with bodily movement of teeth. The expanded arch width dimensions are greater than what would be expected as a result of normal growth.

Dental Arch Width in Children and Relationship to their Oral Habits

2019 ◽  
pp. 6-11
Author(s):  
Kohinur Akther ◽  
Md Zakir Hossain
Keyword(s):  
School Children ◽  
Cross Sectional Study ◽  
Primary School Children ◽  
Dental Arch ◽  
Sectional Study ◽  
Cross Sectional ◽  
Oral Habits ◽  
Arch Width ◽  
Bangladeshi Population ◽  
Dental Arch Width

Aim: Objectives: To analyze variations in dental arch width in relation to oral habits.   Materials and Methods : Cross sectional  study was carried out Department of Orthodontics & Dentofacial Orthopedics of Dhaka Dental College & Hospital, Dhaka with a total number of 600 primary school children of 3-6 years ages of Bangladeshi population. Results: This study was a cross sectional study conducted among the 600 children with 3-6 years old prima- ry school children of Bangladeshi population. According to present study, bottle feeding causes significant reduction in maxillary intercanine width and mouth breathers show significant reduction of both arches. Conclusion: It was observed that the children who had used a bottle had a significant reduction in maxillary intercanine width. Breathing through mouth appeared to be associated with a reduction in the size of both arches. This was more significant in the maxillary intercanine , mandibular  intercanine and mandibular molar widths. Therefore to prevent malocclusions, the public should be informed of the harm caused by certain oral habits, the benefits of breast-feeding, and the need to correct bad habits at early life. Ban J Orthod & Dentofac Orthop, April 2016; Vol-7 (1-2), P.6-11

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

scholarly journals A Repeatable and Reproducible Digital Method to Quantify the Cement Excess and Enamel Loss after Debonding Lingual Multibracket Appliance Therapy

2021 ◽  
Vol 11 (3) ◽  
pp. 1295
Author(s):  
Alba Belanche Monterde ◽  
Alberto Albaladejo Martínez ◽  
Alfonso Alvarado Lorenzo ◽  
Adrián Curto ◽  
Jorge Alonso Pérez-Barquero ◽  
...  
Keyword(s):  
Measurement Technique ◽  
Measurement Method ◽  
Dental Arch ◽  
Micro Computed Tomography ◽  
Morphometric Measurement ◽  
Before And After ◽  
Repeatability And Reproducibility ◽  
Lingual Brackets ◽  
Multibracket Appliance ◽  
Area And Volume

The aim of the present study is to present a repeatable, reproductible, and accurate morphometric measurement method for measuring and quantifying the area and volume of cement that remains after fixed lingual multibracket appliance debonding, enamel loss after fixed lingual multibracket appliance debonding, and the volume of cement used to adhere fixed lingual multibracket appliances. Ten conventional lingual brackets were cemented in 10 extracted teeth embedded into an epoxy resin model simulating a dental arch. This model was scanned before and after bonding the lingual brackets, after debonding, and after polishing the surfaces. We also performed a Micro-Computed Tomography scan of the lingual brackets used. Afterward, the standard tessellation language (STL) digital file was aligned, each tooth was segmented individually, and the file was re-aligned using engineer morphometry software. Inter-operator and intra-operator comparative analyses were performed using the ANOVA test, and the repeatability and reproducibility of the morphometric measurement technique were analyzed using Gage R&R statistical analysis. Repeatability showed 0.07% and 0.16% variability associated with the area and volume measures, respectively, while reproducibility showed 0.00% variability associated with the area and volume measures, respectively. In conclusion, the morphometric measurement technique is a repeatable, reproductible, and accurate morphometric measurement method for quantifying the area and volume of cement that remains after fixed lingual multibracket appliance debonding, enamel loss after fixed lingual multibracket appliance debonding, and the volume of cement used to adhere fixed lingual multibracket appliances.

Impact of Age and Body Mass Index on Anthropometry in Working Adults

2017 ◽  
Vol 61 (1) ◽  
pp. 1341-1345 ◽  
Author(s):  
Zachary Merrill ◽  
April Chambers ◽  
Rakié Cham
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Center Of Mass ◽  
Biomechanical Model ◽  
Whole Body ◽  
Working Adults ◽  
Biomechanical Models ◽  
Scan Data ◽  
Body Segment Parameters ◽  
The Impact

Body segment parameters (BSPs) such as segment mass and center of mass are used as inputs in ergonomic design and biomechanical models to predict the risk of musculoskeletal injuries. These models have been shown to be sensitive to the BSP values used as inputs, demonstrating the necessity of using accurate and representative parameters. This study aims to provide accurate BSPs by quantifying the impact of age and body mass index on torso and thigh mass and center of mass in working adults using whole body dual energy x-ray absorptiometry (DXA) scan data. The results showed significant effects of gender, age, and body mass index (BMI) on torso and thigh mass and center of mass, as well as significant effects of age and BMI within genders, indicating that age, gender, and BMI need to be taken into account when predicting BSPs in order to calculate representative ergonomic and biomechanical model outputs.

scholarly journals Testing the impact of two key scan parameters on the quality and repeatability of measurements from CT scan data

10.26879/942 ◽  
2020 ◽  
Author(s):  
Rosie Oakes ◽  
Morgan Hill Chase ◽  
Mark Siddall ◽  
Jocelyn Sessa
Keyword(s):  
Ct Scan ◽  
Scan Data ◽  
The Impact

scholarly journals Effect of the presence of orthodontic brackets on intraoral scans

2020 ◽  
Vol 91 (1) ◽  
pp. 98-104
Author(s):  
Sung-Ja Kang ◽  
Youn-Ju Kee ◽  
Kyungmin Clara Lee
Keyword(s):  
Cross Sections ◽  
Tooth Movement ◽  
Vertical Section ◽  
Three Dimensional ◽  
Orthodontic Brackets ◽  
Horizontal Section ◽  
Arch Width ◽  
Tooth Surfaces ◽  
The Cross ◽  
Width Measurements

ABSTRACT Objectives The need for intraoral scanning in the presence of brackets has increased for monitoring tooth movement during orthodontic treatment. The purpose of this study was to evaluate the effect of orthodontic brackets bonded to tooth surfaces on intraoral scans. Materials and Methods Intraoral scans were performed in 30 patients using both iTero and Trios scanners before and after bonding of the brackets. The two sets of intraoral scans of each patient and intraoral scans with and without brackets were superimposed using a best-fit algorithm, and three-dimensional (3D) surface analysis was performed. In each superimposition, discrepancies in the 3D axes and arch-width measurements in the incisor and molar regions were compared. In addition, the range of distortion around the brackets was evaluated on the cross sections of each superimposition. Results The overall discrepancies between the intraoral scans with and without brackets were within 0.30 mm. The arch-width discrepancies in the molar region were greater than those in the incisor region, but the differences were not statistically significant (P = .972 for iTero; P = .960 for Trios). The cross sections of the superimposed intraoral scans with and without brackets showed that the deviations were within 0.40 mm in the horizontal section and within 0.35 mm in the vertical section around the brackets. Conclusions The results of this study indicate that the accuracy of intraoral scans, even in the presence of brackets, is clinically acceptable, and the regions beyond 0.50 mm around the brackets should be used for superimposition on images without brackets.

scholarly journals A Multi-Objective Approach to Mitigate Negative Side Effects

2020 ◽  
Author(s):  
Sandhya Saisubramanian ◽  
Ece Kamar ◽  
Shlomo Zilberstein
Keyword(s):  
Side Effects ◽  
Empirical Evaluation ◽  
Primary Objective ◽  
Maximum Deviation ◽  
Negative Side ◽  
Multi Objective ◽  
Markov Decision ◽  
Secondary Objective ◽  
Negative Side Effects ◽  
The Impact

Agents operating in unstructured environments often create negative side effects (NSE) that may not be easy to identify at design time. We examine how various forms of human feedback or autonomous exploration can be used to learn a penalty function associated with NSE during system deployment. We formulate the problem of mitigating the impact of NSE as a multi-objective Markov decision process with lexicographic reward preferences and slack. The slack denotes the maximum deviation from an optimal policy with respect to the agent's primary objective allowed in order to mitigate NSE as a secondary objective. Empirical evaluation of our approach shows that the proposed framework can successfully mitigate NSE and that different feedback mechanisms introduce different biases, which influence the identification of NSE.

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