Fatemeh Gorjizadeh; Maryam Javaheri Mahd; Abdo Rahim Maktabi
Abstract
Background: Prediction of the mesio-distal width of the unerupted premolars and canine is an important point to the practitioner.
Objectives: The main goal of this study was to find the relationship of the teeth size to be used when needed in treatments planning. Materials and Methods: 200 plaster casts ...
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Background: Prediction of the mesio-distal width of the unerupted premolars and canine is an important point to the practitioner.
Objectives: The main goal of this study was to find the relationship of the teeth size to be used when needed in treatments planning. Materials and Methods: 200 plaster casts including 5600 teeth were measured and studies. A caliper with accuracy of 0.1 mm was used for measuring teeth and most teeth were measured twice and the average value was considered as the teeth size. In all cases, the vernier calipers jaws were moved along the teeth longitudinal axis and the biggest width was measured in the contact point area.
Results: Tables of mesiodistal widths of the permanent teeth and some equations were prepared. The measurement difference varied from 0 to 0.04 mm. the average value of difference was 0.016 mm with SD of 0.02 mm. All teeth in male are bigger than those in female and this different is most evident in canine teeth, especially the lower jaw canine teeth.
Conclusions: At the end of this study an equation was found which was used to measure the total value of mesiodistal width of canine and premolar teeth of upper and lower jaws in a simple and exact way.
Mohammad Hossein Toode Zaeim; Soghra Yassaei; Hoori Mir Mohamad Sadeghi; Valiollah Rafiei
Abstract
Aim: A high percentage of the problems in finishing phase are due to tooth size imbalances that can be diagnosed in initial stages of treatment. The purpose of present study is to evaluate the frequency of anterior tooth size discrepancies by Bolton Analysis among class I, II and III malocclusions.Materials ...
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Aim: A high percentage of the problems in finishing phase are due to tooth size imbalances that can be diagnosed in initial stages of treatment. The purpose of present study is to evaluate the frequency of anterior tooth size discrepancies by Bolton Analysis among class I, II and III malocclusions.Materials and methods: The mesio-distal widths of six anterior teeth in 90 paired casts of patients (class I, II, and III), who were selected non-randomly, were measured. Chi-square test was performed to compare the frequency of anterior tooth size discrepancies between the three malocclusion groups. Analysis of variance was used to compare the mean anterior Bolton ratios as a function of skeletal anterior-posterior malocclusions and both genders. Mean mesio-distal width of six anterior teeth were compared by Analysis of variance in 3 skeletal malocclusion groups. Statistical differences were determined at the 95% confidence level.Results: Discrepancy was greater in class I and III than in class II. No sex difference was shown to exist in Bolton anterior ratio. mesio-distal width of upper laterals had greater variation coefficient.
Conclusion: Difference of mean anterior tooth size discrepancies among three skeletal class I, II and III malocclusions were not statistically significant.
Farzin Heravi; Maryam Rezaee
Abstract
Aim: An appropriate occlusal relationship, when there is a significant tooth size discrepancy between the lower and upper dental arches, is impossible. In this way, it is necessary to assess the Bolton's anterior and overall ratios. But it seems too difficult to Measure 24 teeth for each patient routinely. ...
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Aim: An appropriate occlusal relationship, when there is a significant tooth size discrepancy between the lower and upper dental arches, is impossible. In this way, it is necessary to assess the Bolton's anterior and overall ratios. But it seems too difficult to Measure 24 teeth for each patient routinely. in this research our aim was to find an appropriate substitute for the Bolton ratio.
Material and Methods: One hundred pairs of dental casts were selected and the mesiodistal width of each tooth was measured by a sharpened gauge. Then correlation between lateral ratio (mesiodestal width of lower lateral incisors/ upper lateral incisors) and Bolton's anterior ratio (AR) and overall ratio (OR) was evaluated by paired T test and regression models.
Results: Mean overall ratio was 91:3 %, anterior ratio 79.0% and lateral ratio 88.4%correspondingly. No significant difference was found between males and females. A well correlation was found between LR and AR (r=0.70) and OR.
Conclusion: Strong correlation between LR and AR and OR was established. Mean value of 88.4% for LR was correspondent to normal Bolton ratios. (IJO 2006; 1: 53 - 57)
