scholarly journals Tooth Size Discrepancies among Different Malocclusions in a Japanese Orthodontic Population

2008 ◽  
Vol 78 (6) ◽  
pp. 994-999 ◽  
Author(s):  
Toshiya Endo ◽  
Ryota Abe ◽  
Hiroo Kuroki ◽  
Kenji Oka ◽  
Shohachi Shimooka

Abstract Objective: To identify the possible sex differences in anterior and overall tooth size ratios and to evaluate whether any differences exist in tooth size ratios and distributions of subjects with clinically significant tooth size discrepancies among Angle Class I, Class II, and Class III malocclusion groups with the corresponding skeletal characteristics in a Japanese population. Materials and Methods: Each malocclusion group comprised 60 subjects (30 males and 30 females). The mesiodistal width from first molar to first molar was measured on each pretreatment cast to the nearest 0.01 mm using digital calipers, and the anterior and overall ratios were calculated. Student's t-test, Welch t-test, analysis of variance, and χ2-test were performed for statistical analysis. Results: No statistically significant sex differences were found in anterior or overall ratio in any group. No significant differences in anterior or overall ratios were found among the malocclusion groups. No significant differences were found between the distributions of subjects with clinically significant tooth size discrepancies, categorized by the Bolton standard deviation definition and by the actual amount of change calculated for tooth size correction in millimeters, among the malocclusion groups except for the mandibular correction for the overall ratio between Class I and Class III subjects. Conclusion: Bolton's values can be used with confidence for the typical Japanese orthodontic population. The use of the actual millimeters of correction for the tooth size ratios could help orthodontists avoid underestimating the prevalence of clinically significant tooth size discrepancies.

Author(s):  
Md Liakat Ali Hyder ◽  
MSA Mamun ◽  
MZ Hossain

Objectives: To identify the possible sex differences in anterior, posterior, and overall tooth size ratios and to evaluate whether any differences exist in tooth size ratios and distribution of subjects with clinically significant tooth size discrepancies among Angle class I, class II, & class III malocclusion groups in Bangladeshi Orthodontic population. Materials and Methods: Each malocclusion group comprised 40 subjects (20 males and 20 females).The mesiodistal width from first molar to first molar were measured on each pretreatment cast to the nearest 0.01mm using digital calipers, and the anterior, posterior and overall ratios were calculated. Students t-test, Wilcoxon nonparametric test, analysis of variance, and x2-test were performed for statistical analysis. Results: No statistically significant differences in anterior, posterior, or overall ratios were found among the malocclusion groups. No significant sex differences were found in anterior, posterior, or overall ratio in any group, Significant anterior and overall tooth size discrepancies outside 2 SD from the Bolton's means were found in 31% and11.6% of all malocclusion subjects respectively. Conclusion: Bolton's values can be used with confidence for the Bangladeshi orthodontic population. DOI: http://dx.doi.org/10.3329/bjodfo.v2i2.16158 Ban J Orthod & Dentofac Orthop, April 2012; Vol-2, No.2, 8-17


Author(s):  
Joko Kusnoto

  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.


2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Rajeev Kumar Mishra ◽  
Dashrath Kafle ◽  
Rahul Gupta

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.


2014 ◽  
Vol 3 (1) ◽  
pp. 8-13
Author(s):  
Demet Kaya ◽  
Tülin Taner ◽  
Derya Germeç-Çakan

ABSTRACT Aim The objectives of this study were to investigate the effects of tooth extraction and air-rotor stripping therapy on tooth-size discrepancy, and to compare the changes between two groups. Materials and methods The sample comprised the preand post-treatment dental models of 20 postadolescent class I borderline patients. First group was composed of dental models of 10 patients (mean age of 17.1 ± 2.5 years) treated with four first premolars extraction. Second group included dental models of 10 patients (mean age of 18.8 ± 2.7 years) treated with air-rotor stripping. Treatment effects on Bolton overall and anterior ratios/values were analyzed by paired sample t-test and independent sample t-test was used for intergroup comparisons. Results The change in Bolton overall ratio was found statistically significant for the extraction and insignificant for the air-rotor stripping group. A statistically significant decrease was observed in Bolton anterior ratio for the air-rotor stripping group. Neither four premolars extraction nor air-rotor stripping therapy created statistically significant changes in Bolton overall/anterior values. The changes in Bolton overall ratio/value did not show a statistically significant difference between the groups. Conclusion This study showed that tooth extraction or air-rotor stripping therapy did not have an unfavorable effect on toothsize discrepancy in class I borderline patients. How to cite this article Kaya D, Taner T, Germeç-Çakan D. Comparison of Effects of Tooth Extraction and Air-rotor Stripping Therapy on Tooth-size Discrepancy in Class I Borderline Patients. Int J Experiment Dent Sci 2014;3(1):8-13.


2009 ◽  
Vol 79 (4) ◽  
pp. 740-746 ◽  
Author(s):  
Toshiya Endo ◽  
Kenji Uchikura ◽  
Katsuyuki Ishida ◽  
Isao Shundo ◽  
Kosuke Sakaeda ◽  
...  

Abstract Objective: To determine an appropriate threshold for clinically significant tooth-size discrepancy using both a Bolton standard deviation (SD) definition and a millimetric definition. Materials and Methods: Mesiodistal tooth widths were measured in 250 pretreatment dental casts of patients with Class I, Class II, and Class III malocclusions. The anterior and overall ratios and the required amount of maxillary and mandibular corrections were calculated. The casts were divided into small, normal, and large groups according to the anterior and overall ratios categorized by the Bolton SD definition, and into small, normal, and large groups according to the required amount of maxillary and mandibular corrections expressed in millimeters. Results: The small and large anterior ratio groups which fell under the category of the 2 SD threshold did not always need maxillary or mandibular corrections greater than 2 mm, while the small and large overall ratio groups always needed maxillary and mandibular corrections greater than 2 mm. The small and large maxillary correction groups in the 2 mm threshold category did not always have anterior or overall ratios greater than 2 SDs from the Bolton mean. However, the small and large mandibular correction groups always had anterior ratios greater than 2 SDs and did not always have overall ratios greater than 2 SDs. Conclusions: The tooth-size discrepancies could be better expressed in terms of both percentage and actual amount of millimeters required for correction. The ratios outside 2 SDs from the Bolton mean and the discrepancies requiring more than 2 mm of maxillary and/or mandibular corrections are recommendable as the appropriate thresholds for clinical significance.


2007 ◽  
Vol 77 (4) ◽  
pp. 668-674 ◽  
Author(s):  
Siti Othman ◽  
Nigel Harradine

Abstract Objective: To explore how many millimeters of tooth size discrepancy (TSD) are clinically significant, to determine what percentage of a representative orthodontic population has such a tooth size discrepancy, and to determine the ability of simple visual inspection to detect such a discrepancy. Materials and Methods: The sample comprised 150 pretreatment study casts with fully erupted and complete permanent dentitions from first molar to first molar, which were selected randomly from 1100 consecutively treated white orthodontic patients. The mesiodistal diameter tooth sizes were measured using digital calipers, and the Bolton analysis and the tooth size corrections were calculated by the Hamilton Arch Tooth System (HATS) software. Simple visual estimation of Bolton discrepancy was also performed. Results: In the sample group 17.4% had anterior tooth-width ratios and 5.4% had total arch ratios greater than 2 of Bolton's standard deviations from Bolton's mean. For the anterior analysis, correction greater than ± 2 mm was required for 16% of patients in the upper arch or 9% in the lower arch. For the total arch analysis, the corresponding figures are 28% and 24%. Conclusions: It is recommended that 2 mm of required tooth size correction is an appropriate threshold for clinical significance. A significant percentage of patients have a TSD of this size. Visual estimation of TSD has low sensitivity and specificity. Careful measurement is more frequently required in clinical practice than visual estimation would suggest.


2017 ◽  
Vol 7 (2) ◽  
pp. 114-117
Author(s):  
Manish Sonawane ◽  
Ravindranath V Krishnan ◽  
Girish R Karandikar ◽  
Samay Tahilramani

ABSTRACT Aim To evaluate the effect of bi-jaw premolar extractions on Bolton tooth size discrepancy in patients of Indian origin, all of which exhibited a bilateral Angle’s class I molar relationship. Materials and methods Ninety sets of pretreatment study casts, which constituted the sample for the study, were divided into three groups, namely, Bolton small (BS), Bolton normal (BN), and Bolton big (BB). Simulated bi-jaw extraction of premolars was carried out in four different combinations for each set of study cast. The four values of Bolton’s overall ratio (BOR) thus obtained were compared with the original BOR value. Results The BOR value reduced when subjected to any of the four combinations of bi-jaw premolar extractions. Conclusion Premolar extraction in any combination inevitably changes the BOR value, which potentially affects the settling of occlusion toward the finishing stages of orthodontic treatment. Clinical significance The present study provides an insight into the choice of bi-jaw premolar extraction combination for each of the three groups in patients exhibiting class I malocclusion in the Indian population. How to cite this article Tahilramani S, Karandikar GR, Krishnan RV, Sonawane M. Effect of Bi-jaw Premolar Extractions on Tooth Size Discrepancy in an Indian Population having Class I Malocclusion: An in vitro Study. J Contemp Dent 2017;7(2):114-117.


2018 ◽  
Vol 7 (2) ◽  
pp. 9-14
Author(s):  
Rajiv Kumar Mishra ◽  
Om Prakash Kharbanda ◽  
Rajiv Balachandran

Introduction: Evaluation of temporo-mandibular joint (TMJ) anatomy and function is an essential part of orthodontic diagnosis and treatment planning. It has been hypothesized that dental and skeletal malocclusions alter the functional loading of TMJ which can affect joint morphology.Objective: Three dimensional (3D) evaluation of condylar position using CBCT in skeletal Class I and Class III growing subjects.Materials & Method: CBCT images of ten growing skeletal Class I & ten Class III patients in the age range of 7-14 years were analyzed. 3D condylar position were evaluated representing antero-posterior, vertical, laterolateral position of condyle, axial condylar angle and coronal condylar angles which were measured in axial, coronal and sagittal sections using Dolphin Imaging software. Antero-posterior and vertical difference of right and left condyle were measured in axial and coronal sections respectively.Result: Paired t-Test revealed no significant difference between right and left sides of condyle in skeletal Class I as well as Class III subjects. Independent t-test and Mann-Whitney U test showed no significant difference between position of condyle in ClassI and Class III subjects.Conclusion: 3D CBCT analysis shows no significant difference in condylar position of skeletal Class I and Class III subjects.


2002 ◽  
Vol 26 (4) ◽  
pp. 383-387 ◽  
Author(s):  
Eman Alkofide ◽  
Hayder Hashim

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.


2020 ◽  
Vol 10 (1) ◽  
pp. 32-37
Author(s):  
Rawand J. Othman ◽  
Jameel A. Alkhashan

It is essential to know the tooth crown size to provide accurate diagnosis and treatment planning to ensure the satisfactory outcome of orthodontic treatment. The aim of the present study was to measure and compare mesiodistal crown diameter of a Kurdish sample in Erbil city with normal and different classes of malocclusion. The mesiodistal tooth width was measured by an electronic digital caliper on a total of 150 (75 males and 75 females) orthodontic models of secondary school students of different occlusal relationships (Class I normal occlusion, Class I, Class II division I, Class II division II, and Class III malocclusions). The results showed that (1) the maxillary right first molar was significantly larger than the left one and both maxillary right lateral incisors and first premolars were larger than their contralateral teeth at the level of P < 0.01. (2) Both upper and lower canine were significantly smaller in females than in males; (3) Class I malocclusion showed tendency toward larger teeth than the rest of the other occlusal categories; (4) no statistically significant differences in tooth size were found among the Class II division I, division II, and Class III malocclusions when compared to normal occlusion. In conclusion, females had smaller teeth than males and there was asymmetry between the right and left sides in tooth size and Class I malocclusion showed tendency toward larger teeth.


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