Allahyar Geramy; Maryam Moghaddas Bayat
Abstract
Background: During mixed dentition period, one can make accurate estimation of future dental development and can assess whether there will be enough space in the dental arch. In orthodontics treatment planning, it is vital to predict space required for unerupted canine and premolars in the arch.
Objectives: ...
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Background: During mixed dentition period, one can make accurate estimation of future dental development and can assess whether there will be enough space in the dental arch. In orthodontics treatment planning, it is vital to predict space required for unerupted canine and premolars in the arch.
Objectives: The main goal of this study is to compare different teeth combinations in predicting needed space for unerupted canine and premolars on Bayesian approach and introduce the most reliable one.
Patients and Methods: The sample for this study consists of 47 dental casts (19 males, 28 females) with complete erupted dental arches. The meisodistal width of all teeth was measured using a dental caliper. We consider different combinations of teeth size and compare them to find the best predictor. In order to do that, quantile regression and Bayesian approach are applied using “R software”. Results: Combination of first maxillary molars with sum of central and lateral mandibular incisors has the smallest standard deviation. This is true for male and female samples. The regression formula based on this teeth combination has been introduced.
Conclusions: In our sample, combination of Mandibular incisors and maxillary first molar is found to be better than the other predictors for female and female model in both arches.
Mohammad Hossein Toodehzaeim; Hossein Aghili; Hoori Mirmohammadsadeghi; Elham Shariatifar
Abstract
Aim: To compare the prediction of unerupted permanent canine and premolar size of a comparable sample size of Iranian (Yazd) population with that of the study of Tanaka and Johnston.Materials and Methods: Teeth on study casts of an unselected sample from a 11 to 25 years old (n 120; 60 males and 60 females) ...
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Aim: To compare the prediction of unerupted permanent canine and premolar size of a comparable sample size of Iranian (Yazd) population with that of the study of Tanaka and Johnston.Materials and Methods: Teeth on study casts of an unselected sample from a 11 to 25 years old (n 120; 60 males and 60 females) were measured in the mesiodistal dimension. An Iranian mixed dentition analysis based on the Tanaka and Johnston method was constructed with new linear regression equations for prediction of the mesiodistal widths of unerupted canines and premolars. Digital calipers were used to measure the mesiodistal widths of all teeth on study models fabricated from alginate impressions. The predicted widths of the canines and the premolars in both arches were compared with the actual measured widths.Results: Sexual dimorphism was evident between Iranian (Yazd) males and females in incisors, canines, and premolars in the mesiodistal dimension.Conclusions: To predict the space (in mm) required for alignment of unerupted canine and premolars in Iranian(Yazd) children, divide the sum of the mesiodistal dimensions of the four mandibular incisors by two and add the respective constants for males (upper, 12.91; lower, 10.51) or females (upper, 9.09; lower, 8.22).
Farzin Heravi; Alireza Pourali
Abstract
Aim: Tanaka and Johnston have offered a very simple method for estimating mesio-distal witdh of unerupted canines and premolars; But it seems that these estimations are not appropriate for Iranian population. In this investigation we've tried to offer a new formula to estimate the width of unerupted ...
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Aim: Tanaka and Johnston have offered a very simple method for estimating mesio-distal witdh of unerupted canines and premolars; But it seems that these estimations are not appropriate for Iranian population. In this investigation we've tried to offer a new formula to estimate the width of unerupted teeth in Iranians.
Material and method: In this study we measured the size of premolars and canins on 400 dental casts and did a regression analysis to find any correlation between the size of these teeth and four lower incisors.
Results: We found that using Tanaka and Johnston analysis in Iranian children, unerupted teeth estimated wider than actual size.This study showed that there was a strong correlation between the width of lower incisors and unerupted canine and premolars of both jaws in Iranian population.
Conclusion: As we found Tanaka and Johnson's formula will estimate canines and premolars wider and a new formula is offered for Iranian population.