scholarly journals Digital analysis of tooth sizes among individuals with different malocclusions: A study using three-dimensional digital dental models

2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110381
Author(s):  
Beyza Karadede Ünal ◽  
Deniz Dellaloğlu
Keyword(s):  
Three Dimensional ◽  
Class Ii ◽  
Tooth Size ◽  
Digital Models ◽  
Three Dimensional Model ◽  
Digital Format ◽  
Significant Difference ◽  
Three Dimensional Measurement ◽  
Anterior Ratio ◽  
Overall Ratio

Objective: It is aimed to examine the tooth sizes of digital models of patients with different malocclusions with the help of three-dimensional measurement software. Methods: Digital models of 252 patients aged between 13 and 25 years of age were included. According to the Angle classification, three different malocclusion groups were allocated such that there were 84 patients in each group, plaster models of patients scanned with the three-dimensional model browser 3Shape R700 3D Scanner (3Shape A/S Copenhagen, Denmark) and transferred to the digital format. 3Shape Ortho Analyzer (3Shape A/S Copenhagen, Denmark) software was used for making the necessary tooth size measurements. Results: When the measurements were evaluated, it was determined that significant changes occurred between tooth sizes of individuals with different malocclusions. Generally, higher values were observed in mesiodistal and buccolingual tooth dimensions of class II individuals compared to other groups. There was no difference between the groups in the anterior ratio values, but when the overall ratio values were evaluated among the groups, a statistically significant difference was determined. Class II malocclusion group was found to have a significantly lower overall ratio of occurrence. Conclusion: Individuals with different malocclusions differ in tooth size.

scholarly journals THE RELIABILITY OF THE BOLTON RATIO WHEN APPLIED TO THE INDONESIAN POPULATION

2017 ◽  
Vol 10 (10) ◽  
pp. 176
Author(s):  
Joko Kusnoto
Keyword(s):  
T Test ◽  
Tooth Size ◽  
Crown Width ◽  
Indonesian Population ◽  
Significant Difference ◽  
The Mean ◽  
Anterior Ratio ◽  
Overall Ratio ◽  
Student’S T ◽  
Student’S T Test

  Objective: The objective of this study is to determine whether Bolton ratio can be applied clinically to the Indonesian population and to determine a more suitable Bolton ratio for the Indonesian population.Methods: This study was conducted on 120 readily available study models of treated cases comprising 37 males and 83 females. Two investigators separately measured the mesiodistal crown width of maxillary and mandibular tooth on each study model using sliding calipers. According to Bolton’s method, the overall and anterior ratios from each sample were calculated and the mean was generated. Using Student’s t-test with a 95% confidence interval, the investigators compared whether there is a significant difference between the ratio from Bolton’s samples and the ratio from the Indonesian samples.Results: The result of this study showed that, for Indonesian samples, the overall ratio is 89.7±2.05, while the anterior ratio is 76.4±2.76. Student’s t-test showed that there is a statistically significant difference (p<0.05) between the results of this study and that of Bolton’s study for both the anterior and overall ratios.Conclusion: It can be concluded that there is a difference between Indonesian population and Caucasian population in tooth size and Bolton ratio value. Therefore, original Bolton ratio value cannot be used as an accurate diagnostic tool for Indonesian population.

scholarly journals Analysis of Interarch Tooth Size Relationship in Nepalese Subjects with Normal Occlusion and Malocclusions

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Rajeev Kumar Mishra ◽  
Dashrath Kafle ◽  
Rahul Gupta
Keyword(s):  
Study Groups ◽  
Class Ii ◽  
Class I ◽  
Tooth Size ◽  
Class Ii Malocclusion ◽  
Normal Occlusion ◽  
Size Discrepancy ◽  
Clinically Significant ◽  
Anterior Ratio ◽  
Overall Ratio

Introduction. A proportional relationship between the maxillary and mandibular teeth size is required for achieving good finish with proper overjet and overbite postorthodontic treatment. The aims and objectives of this study were to determine the anterior and overall Bolton’s ratio in Nepalese population, to compare Bolton’s ratio between subjects with normal occlusion, Class I malocclusion, and Class II malocclusion, to compare these results with Bolton’s norm, and to determine the frequency of clinically significant (beyond 2 SD) tooth size discrepancy compared to Bolton’s norm. Materials and Methods. The study models of the subjects with normal occlusion and Angle’s Class I malocclusion and Class II malocclusion and fulfilling the inclusion criteria were retrieved from department archives. An electronic digital caliper was used to measure mesiodistal tooth size of the maxillary and mandibular teeth anterior to the second molars. The study sample of 120 study models consisted of the normal occlusion group (n = 31), Class I malocclusion group (n = 47), and Class II malocclusion group (n = 42). These measurements were then used to obtain Bolton’s ratio in three groups of subjects. Bolton’s ratio of study groups was compared with each other and with Bolton’s original ratio. Results. The differences in tooth size ratio of the study groups were not significant statistically, when the groups were compared on the basis of malocclusion or gender. Statistically significant differences were exclusively observed between the study groups and Bolton’s original sample for the anterior ratio. The frequency of the clinically significant tooth size ratio discrepancy was lower for the overall ratio (9.1%) compared to the anterior ratio (22.5%). Conclusions. Bolton’s analysis on the Nepalese population sample shows that there was no significant difference observed on the anterior and overall tooth size ratios when these were compared based on Angle’s malocclusion classes or gender. The clinically significant anterior tooth size discrepancy was more prevalent than that of the overall ratio.

Intermaxillary tooth size discrepancies among different malocclusion classes: a comparative study

2002 ◽  
Vol 26 (4) ◽  
pp. 383-387 ◽  
Author(s):  
Eman Alkofide ◽  
Hayder Hashim
Keyword(s):  
Size Analysis ◽  
Tooth Size ◽  
Class Iii ◽  
Mean Values ◽  
Normal Occlusion ◽  
Significant Difference ◽  
Important Diagnostic Tool ◽  
Males And Females ◽  
Anterior Ratio ◽  
Overall Ratio

The purpose of this study is to determine whether a difference exists in intermaxillary tooth size among different malocclusion groups in Saudi patients. The study consisted of 240 pretreatment orthodontic casts (Sixty cases in each malocclusion class, in addition to normal occlusion). The results of the study shows no significant difference in the incidence of tooth size discrepancies for the overall ratio and anterior ratio between the different malocclusion groups, except for the anterior ratio in class III malocclusion. Further, no statistical significant difference was observed between males and females. When the mean values of the present study were compared to that of Bolton's, a significant difference was found in all the malocclusion classes.We can conclude from this study that Bolton tooth size analysis is an important diagnostic tool, and should be taken into consideration before initiation of orthodontic treatment.

scholarly journals Bolton’s Tooth Size Discrepancy in Malaysian Orthodontic Patients: Are Occlusal Characteristics Such as Overjet, Overbite, Midline, and Crowding Related to Tooth Size Discrepancy in Specific Malocclusions and Ethnicities?

2018 ◽  
Vol 8 ◽  
pp. 36-43 ◽  
Author(s):  
Priti Subhash Mulimani ◽  
Myra Innessa Binti Azmi ◽  
Nabilah Rashida Jamali ◽  
Nur Najaa Binti Md Basir ◽  
Htoo Htoo Kyaw Soe
Keyword(s):  
Tooth Size ◽  
Class Iii ◽  
Midline Shift ◽  
Entire Study ◽  
Significant Difference ◽  
Size Discrepancy ◽  
Orthodontic Patients ◽  
Tooth Size Discrepancy ◽  
Anterior Ratio ◽  
Overall Ratio

Introduction Tooth size, occlusal traits, and ethnicity are closely interrelated, and their impact on desirable orthodontic treatment outcome cannot be underestimated. This study was undertaken to assess the occlusal characteristics and ethnic variations in occlusion of Malaysian orthodontic patients and evaluate their correlation with Bolton’s tooth size discrepancy. Materials and Methods On 112 pretreatment study models of orthodontic patients, molar relationship, overjet, overbite, spacing, crowding, midline shift, and Bolton’s ratios were assessed. ANOVA, one-sample t-test, Chi-squared test, and Spearman’s rho correlation coefficient were used for statistical analysis. Results Significant difference between anterior ratio of our study and Bolton’s ideal values was found, for the entire study sample and Chinese ethnic group. Differences between races and malocclusion groups were not statistically significant (P > 0.05). Significant correlations were found as follows – in Angle’s Class I malocclusion between 1) anterior ratio and overbite, 2) overall ratio and maxillary crowding and spacing; in Angle’s Class II malocclusion between 1) anterior ratio and overjet and midline shift, 2) overall ratio and mandibular crowding; in Angle’s Class III malocclusion between 1) anterior ratio and mandibular crowding and both maxillary and mandibular spacing 2) overall ratio and mandibular crowding. Conclusions Significant differences in anterior ratio and Bolton’s ideal values for the Malaysian population were found, indicating variations in anterior tooth size as compared to Caucasians. Statistically significant correlations existed between Bolton’s ratios and occlusal traits. These findings can be applied clinically in diagnosis and treatment planning by keeping in mind the specific discrepancies that can occur in certain malocclusions and addressing them accordingly.

scholarly journals Bolton Ratio of Different Angle’s Classifications in a School Children Sample of Erbil City

2020 ◽  
Vol 10 (2) ◽  
pp. 87-97
Author(s):  
Amanj R. Ibrahim ◽  
Zana Q. Omer ◽  
Hasan S. Hasan ◽  
Walaa M. Saleem Almola
Keyword(s):  
Numerical Data ◽  
Class Ii ◽  
Class Iii ◽  
Normal Occlusion ◽  
Significant Difference ◽  
Distal Surface ◽  
Males And Females ◽  
The Mean ◽  
Anterior Ratio ◽  
Overall Ratio

Aims of this study were to determine both the Bolton anterior and overall ratios in a representative sample of Erbil schoolchildren of Normal occlusion and Cl I, Cl II div I, div II, and Cl III malocclusion, also to find if there are any gender differences. Numerical data were obtained, comprised of 320 samples study casts of students with a mean age of 13–15 years selected from different schools in Erbil City. The casts were divided into 5 groups according to the type of malocclusion: Normal (n = 64), Cl I (n = 64), Class II div I (n = 64), Class II div II (n = 64), and Class III subjects (n = 64). The measurement of the greatest mesiodistal width of the teeth was performed using digital Vernier directly on the study casts, from the distal surface of the left first molar to the distal surface of the right first molar. The overall and anterior ratios between the maxillary and mandibular teeth were computed and evaluated using Bolton’s method. The results revealed that the mean anterior ratio (78.863) was higher and statistically signifi cantly different from anterior Bolton’s (77.2) and also the mean overall ratio was not statistically signifi cant different from Bolton’s ratio (91.3) (P = 0.239), with respect to the overall and anterior ratios among all the groups, statistically significant differences were found. Differences between genders were analyzed using a t-test. The results showed that there were no signifi cant differences between males and females. There were non-significant differences between the findings of the present study and those of Bolton’s study for overall ratio and anterior ratio, but among all five classifications, there was a significant difference of Erbil population not similar to Bolton ratio and there was no significant difference between males and females.

scholarly journals Tooth-size discrepancy: A comparison between manual and digital methods

2014 ◽  
Vol 19 (4) ◽  
pp. 107-113 ◽  
Author(s):  
Gabriele Dória Cabral Correia ◽  
Fernando Antonio Lima Habib ◽  
Carlos Jorge Vogel
Keyword(s):  
Three Dimensional ◽  
Diagnostic Tools ◽  
Tooth Size ◽  
Digital Models ◽  
Linear Measurements ◽  
Length Discrepancy ◽  
Technological Advances ◽  
Size Discrepancy ◽  
Digital Methods ◽  
Plaster Models

INTRODUCTION: Technological advances in Dentistry have emerged primarily in the area of diagnostic tools. One example is the 3D scanner, which can transform plaster models into three-dimensional digital models. OBJECTIVE: This study aimed to assess the reliability of tooth size-arch length discrepancy analysis measurements performed on three-dimensional digital models, and compare these measurements with those obtained from plaster models. MATERIAL AND METHODS: To this end, plaster models of lower dental arches and their corresponding three-dimensional digital models acquired with a 3Shape R700T scanner were used. All of them had lower permanent dentition. Four different tooth size-arch length discrepancy calculations were performed on each model, two of which by manual methods using calipers and brass wire, and two by digital methods using linear measurements and parabolas. RESULTS: Data were statistically assessed using Friedman test and no statistically significant differences were found between the two methods (P > 0.05), except for values found by the linear digital method which revealed a slight, non-significant statistical difference. CONCLUSIONS: Based on the results, it is reasonable to assert that any of these resources used by orthodontists to clinically assess tooth size-arch length discrepancy can be considered reliable.

scholarly journals Determination of Bolton Norms for Indian Population Sample

2017 ◽  
Vol 7 (1) ◽  
pp. 33-36 ◽  
Author(s):  
TV Pawan Kumar ◽  
Prasad Chitra
Keyword(s):  
Population Sample ◽  
Tooth Size ◽  
Mean Values ◽  
Class 1 ◽  
Size Discrepancy ◽  
Tooth Size Discrepancy ◽  
Anterior Ratio ◽  
Overall Ratio ◽  
Male Subjects

Introduction: Tooth size discrepancy varies between different ethnic groups and races. Bolton’s tooth size norms were originally determined in Caucasian population.Objective: To determine tooth size ratios for maxillary and mandibular dentition in Telangana population of Indian sample and to compare the ratios with standard Bolton norms.Materials & Method: The study sample comprised of 300 subjects (150 males and 150 females) aged between 14-25 years having Angle’s Class 1 molar relationship. Study models of all subjects were prepared and mesiodistal dimensions were measured to determine mean Bolton’s anterior ratio, overall ratio, over jet and overbite.Result: Evidence of sexual dimorphism was observed with Indian male subjects having greater mean values than the females. The determined mean for anterior tooth ratio was 80.88 ± 3.03%, overall tooth ratio 93.99 ± 3.11%, overjet 2.92 ± 0.62mm and overbite 2.96 ± 0.63mm. Statistically significant differences were found between Indian samples and Bolton Caucasian standards.Conclusion: The study provides evidence that tooth sizes are population specific. Mean values specific to particular population groups should be derived in order to make treatment planning more accurate and predictable.

Three Dimensional Analysis of a Grinding Wheel Surface with Image Processing

2012 ◽  
Vol 565 ◽  
pp. 177-182 ◽  
Author(s):  
Akihiro Sakaguchi ◽  
Tomoyuki Kawashita ◽  
Shuji Matsuo
Keyword(s):  
Image Processing ◽  
Three Dimensional ◽  
Grinding Wheel ◽  
Distribution Map ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Wheel Surface ◽  
Dimensional Measurement ◽  
Surface Topographies ◽  
Three Dimensional Measurement

It is very important to measure a grinding wheel surface topography. Therefore a three dimensional measurement system of grinding wheel surface with image processing has been proposed. This system can evaluate a variety of the wheel surface topographies. For example, a histogram of the area or the shape of cutting edges and the distribution map of every shape of cutting edges were obtained. In this paper, a three dimensional model of the cutting edges and a correlation between the state of the wheel surface and grinding mark on the workpiece are reported and the effectiveness is evaluated through an experiment.

Impact of Welding Sequence on the CRDM Nozzle-to-Vessel Weld Stress Analysis

2004 ◽  
Author(s):  
Yaoshan Chen ◽  
David Rudland ◽  
Gery Wilkowski
Keyword(s):  
Computing Time ◽  
Three Dimensional ◽  
Welding Process ◽  
Element Model ◽  
Three Dimensional Model ◽  
Control Rod ◽  
Moving Source ◽  
Welding Sequence ◽  
Significant Difference ◽  
Three Dimensional Finite Element

A three-dimensional finite element model is presented to simulate the welding process of the side-hill control-rod-drive-mechanism (CRDM) nozzle to the vessel head. Emphasis is given to how the weld is laid out in the analysis so that accurate residual stress results can be obtained while the required computing time is viable. In the order of complexity, three approaches are examined in this study: a) the simultaneous approach, i.e., the weld bead (therefore the heat associated with it) is put in the model in a uniform fashion; b) the piece-by-piece approach, i.e., the weld is laid out segment by segment; c) the moving-source approach where the analysis is done by simulating the moving heat source. It is found that there is a significant difference between the stress results by the uniform approach and the piece-by-piece approach. While the moving source method gives the closet representation of the welding process, the computing time for such a multi-pass, three-dimensional model is still prohibitive. The natural choice is therefore the piece-by-piece approach, with the number of segments for the weld dependent on the weld parameters and the geometries of the nozzle and vessel head.

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