scholarly journals Effect of Bi-jaw Premolar Extractions on Tooth Size Discrepancy in an Indian Population having Class I Malocclusion: An in vitro Study

2017 ◽  
Vol 7 (2) ◽  
pp. 114-117
Author(s):  
Manish Sonawane ◽  
Ravindranath V Krishnan ◽  
Girish R Karandikar ◽  
Samay Tahilramani
Keyword(s):  
Indian Population ◽  
In Vitro Study ◽  
Class I ◽  
Tooth Size ◽  
Premolar Extraction ◽  
Indian Origin ◽  
Size Discrepancy ◽  
Tooth Size Discrepancy ◽  
Overall Ratio

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.

scholarly journals The Effect of Premolar Extraction on Tooth Size Discrepancies of the Patients Treated in Orthodontic Department at BSMMU

2018 ◽  
pp. 13-16
Author(s):  
Nabila Anwar ◽  
Gazi Shamim Hasan
Keyword(s):  
Treatment Plan ◽  
Cross Sectional Study ◽  
Class I ◽  
Tooth Size ◽  
Cross Sectional ◽  
Premolar Extraction ◽  
Before And After ◽  
Size Discrepancy ◽  
Tooth Size Discrepancy ◽  
Overall Ratio

Aims: The present cross sectional study was carried out to investigate the effect of first premolar extraction on tooth size discrepancies (TSD) in an orthodontic population seeking treatment at orthodontic department, BSMMU.Material and methods: Mesiodistal tooth widths were measured on 50 pair of pretreatment and post treatment dental casts of subjects with Class I variation – Class I with bimaxillary proclination, and Class I crowding. The overall ratios and tooth-size discrepancies were determined before and after 1st premolar extractions. Before and after extractions, the subjects were divided into Bolton small (BS), Bolton normal (BN) and Bolton large (BL) overall ratio groups categorized by the Bolton standard deviation definition.Results: The Bolton overall ratio after 1st premolar extraction was smaller than those before extraction in each group. Some of the patients in the BN group and BB group were moved into the BS group and BN group respectively after 1st premolar extraction. A tooth size discrepancy occurred in some patients with normal overall ratios  after premolar extractions, but a tooth size discrepancy might be corrected in some patients with big overall ratios  after premolar extraction.Conclusion: Orthodontists should take into account the following when devising a treatment plan for premolar extractions, overall ratios might decrease and remain normal, and clinically significant tooth-size discrepancies could change mutually after extractions.Ban J Orthod & Dentofac Orthop, April 2015; Vol-5 (1-2), P.13-16

scholarly journals Comparison of Effects of Tooth Extraction and Air-rotor Stripping Therapy on Tooth-size Discrepancy in Class I Borderline Patients

2014 ◽  
Vol 3 (1) ◽  
pp. 8-13
Author(s):  
Demet Kaya ◽  
Tülin Taner ◽  
Derya Germeç-Çakan
Keyword(s):  
Tooth Extraction ◽  
T Test ◽  
Class I ◽  
Tooth Size ◽  
Significant Difference ◽  
Size Discrepancy ◽  
Borderline Patients ◽  
Dental Models ◽  
Tooth Size Discrepancy ◽  
Overall Ratio

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.

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.

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.

scholarly journals A Comparative Analysis of Tooth Size Discrepancy between Male and Female Subjects Presenting with a Class I Malocclusion

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Eva Man Yee Leung ◽  
Yanqi Yang ◽  
Balvinder Khambay ◽  
Ricky Wing Kit Wong ◽  
Colman McGrath ◽  
...  
Keyword(s):  
Class I ◽  
Tooth Size ◽  
Male And Female ◽  
Mean Values ◽  
Southern Chinese ◽  
Size Discrepancy ◽  
Tooth Size Discrepancy ◽  
Males And Females ◽  
The Mean ◽  
Female Subjects

Objectives. To evaluate the tooth size discrepancy and Bolton’s ratios between male and female subjects with a Class I malocclusion. Materials and Methods. The digital e-models of 100 male and 100 female 12-year-old southern Chinese children with a Class I malocclusion were selected. The mesiodistal widths from permanent first molar to the contralateral side first molar of the upper and lower dentitions were measured. Differences between the tooth size discrepancy, together with the anterior and overall Bolton’s ratios between male and female subjects, were assessed using a two-sample t-test. A paired t-test was used to determine differences between antimetric pairs of teeth within the same arch. Results. Females had statistically significant smaller teeth than males (P < 0.05) except the upper left and lower left lateral incisor and lower left and right central incisors. The mean values of anterior Bolton’s ratios for males and females were 77.04 and 77.03, respectively (P > 0.05), while the mean values of overall Bolton’s ratios of male and female are 90.48 and 90.65, respectively (P < 0.05). The clinical significant differences (Cohen’s d > 0.2) for contralateral tooth size were shown on the maxillary canines, lateral incisors, and central incisors of males; and mandibular canines and lateral incisors of females. Conclusions. Southern Chinese females presenting with Class I malocclusions have smaller mesiodistal tooth dimensions compared to males. Both males and females presented several tooth size asymmetries. There are no statistical differences in anterior and overall Bolton’s ratios between the genders.

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 Overall and Anterior Tooth Size Ratios in a Group of Emiratis

2018 ◽  
Vol 12 (1) ◽  
pp. 655-663 ◽  
Author(s):  
Moaza Ghuloom Mohammad ◽  
Shazia Naser-ud Din ◽  
Amar Hassan Khamis ◽  
Athanasios E. Athanasiou
Keyword(s):  
Class Ii ◽  
Anterior Tooth ◽  
Class I ◽  
Tooth Size ◽  
Class Iii ◽  
Mean Values ◽  
Normal Occlusion ◽  
Size Discrepancy ◽  
Tooth Size Discrepancy ◽  
Dental Casts

Objectives:The aims of this investigation in a group of Emiratis were (1) To study overall and anterior tooth size ratios in Class I normal occlusion, (2) To estimate overall and anterior tooth size ratios in different malocclusion groups, (3) To compare overall and anterior tooth size ratios in Class I normal occlusion with the Bolton standards, and (4) To determine the distribution of overall and anterior tooth size ratios ± 2 SD from Bolton mean values in all occlusion groups.Materials and Methods:In this cross-sectional investigation, consecutive patients’ files, including dental casts, were selected from the archives of orthodontic clinics of the Dubai Health Authority. The final sample was formed following the application of specific inclusion criteria. The sample consisted of 521 pairs of dental casts representing both sexes (males: 188; females: 333) and different malocclusion groups (Class I: 288; Class II: 110; Class III: 30) and Class I normal occlusion (93). The mean age of patients was 16.18y for Class I, 15.73y for Class II, 15.83y for Class III, and 16.55y for Class I normal occlusion. The dental casts were scanned and digitized by the first author using the Ortho Insight 3D laser scanner. Measurements were made regarding maxillary and mandibular sums of mesiodistal tooth dimension of the overall (6-6) and anterior (3-3) groups of teeth. Statistical analysis included descriptive statistics, pairedt-test and Analysis of Variance (ANOVA). The level of significance was set atp<0.05.Results:There were statistically significant differences among malocclusion groups with regard to overall and anterior tooth size ratios. However, the comparison between the Class I normal occlusion group and the Bolton standards showed no statistically significant differences. Only five cases in Class II malocclusion presented an anterior tooth size discrepancy outside plus 2 SD from Bolton mean values and one case in Class I malocclusion presented with an overall tooth size discrepancy outside plus 2 SD from Bolton mean values.Conclusion:This study of the different occlusion groups of the Emirati sample concluded that (a) Class I normal occlusion cases presented similar overall and anterior tooth size ratios to Bolton standards; (b) Overall and anterior tooth size ratios among different malocclusion groups exhibited statistically significant differences; (c) Five cases in Class II malocclusion presented an anterior tooth size discrepancy outside plus 2 SD from Bolton mean values, and (d) One case in Class I malocclusion presented an overall tooth size discrepancy outside plus 2 SD from Bolton mean values.

scholarly journals Tooth extractions in Orthodontics: first or second premolars?

2019 ◽  
Vol 24 (3) ◽  
pp. 88-98 ◽  
Author(s):  
Telma Martins de Araújo ◽  
Luciana Duarte Caldas
Keyword(s):  
Class I ◽  
Skeletal Maturation ◽  
Tooth Size ◽  
Facial Profile ◽  
Anterior Crowding ◽  
Patient Cooperation ◽  
Size Discrepancy ◽  
Tooth Size Discrepancy ◽  
Bimaxillary Protrusion ◽  
Tooth Extractions

ABSTRACT Tooth crowding and protrusions demand rigorous attention during orthodontic planning that includes the extraction of first and second premolars. Some characteristics, such as dentoalveolar bone discrepancies, maxillomandibular relations, facial profile, skeletal maturation, dental asymmetries and patient cooperation, are important elements of an orthodontic diagnosis. This study discusses the options of treatments with extractions and describes the correction of a Class I malocclusion, bimaxillary protrusion, severe anterior crowding in both dental arches and tooth-size discrepancy, using first premolar extractions.

scholarly journals Thresholds for Clinically Significant Tooth-Size Discrepancy

2009 ◽  
Vol 79 (4) ◽  
pp. 740-746 ◽  
Author(s):  
Toshiya Endo ◽  
Kenji Uchikura ◽  
Katsuyuki Ishida ◽  
Isao Shundo ◽  
Kosuke Sakaeda ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Clinical Significance ◽  
Tooth Size ◽  
Class Iii ◽  
Size Discrepancy ◽  
Tooth Size Discrepancy ◽  
Clinically Significant ◽  
Anterior Ratio ◽  
Overall Ratio ◽  
Large Groups

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.

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