Mohammad Hossein Toodehzaeim; Seyed Morteza Saadat Mostafavi
Abstract
Background: The aim of this study was to verify the prevalence of three different morphologies of the mandibular and maxillary dental arch in natural normal occlusions and that may help guiding orthodontists customizing shape of orthodontic archwires. The orthodontist should know the mean of inter-canine ...
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Background: The aim of this study was to verify the prevalence of three different morphologies of the mandibular and maxillary dental arch in natural normal occlusions and that may help guiding orthodontists customizing shape of orthodontic archwires. The orthodontist should know the mean of inter-canine and inter-molar width of Iranian population to help as a guide of treatment.
Methods: We examined 132 study models including 66 maxillary and 66 mandibular arches. Three square, ovoid, and tapered templates were overlaid on arches using special software. Samples were categorized according to the adaptability of templates on images. Inter canine and inter molar widths were also measured on casts and recorded. Results: Ovoid was the most frequent form (54%) in Iranian population. Tapered (36%) and square (10%) forms were on second and third steps, respectively. The relative frequencies of tapered and ovoid forms were equal in the mandibular arch while in the maxillary arch, the frequency of ovoid (63%) was significantly higher than tapered (27%).
Conclusions: Ovoid is the most common dental arch form in Iranian population.
Zohreh Hedayati; Abdolaziz Haghnegahdar; Ashkan Bagheri
Abstract
Background and Aim: Age estimation may be needed to plan treatment procedures in pedodontic, and orthodontics. Third molar is the last and most variable tooth to develop and may be used for age estimation in adulthood. The purpose of this study was to investigate relationship between chronological age ...
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Background and Aim: Age estimation may be needed to plan treatment procedures in pedodontic, and orthodontics. Third molar is the last and most variable tooth to develop and may be used for age estimation in adulthood. The purpose of this study was to investigate relationship between chronological age and developmental stages of the mandibular third molar in a population of south Iran.Method: The Demirjian’s classification system was used to evaluate the developmental status of the mandibular third molars on the 500 panoramic radiographs of orthodontic patients. The age range of patients was 12 to 20 years. Mean and Standard deviations of Chronological age for each developmental stages were calculated. One-way ANOVA and post-hoc Tuckey HSD test were used to compare the mean age and developmental stages of molar teeth. The age differences in the developmental stages between the genders was assessed. Correlation between calcification stages of the third molars and age was determined.Results: Crown calcification was completed at the mean age of 13.8 years, and root formation without apex closure was observed at the mean age of 17.5 years. At a mean age of 18.4 years apex closure was occurred. Males were advanced in the most of stages of calcification. A strong correlation between developmental stages of the lower third molars and chronological age was found in both genders.Conclusion: The present investigation could provide reference data for third molar development in our population. Developmental stages of mandibular third molars showed a strong correlation with age. The lower third molars developed earlier in males than females.
Maryam Poosti; Fariborz Amini; Alireza Darnahal; P. Mokhnefi
Abstract
Background and aim: The form of the facial skeleton and dental relationship is race specific, and estimating the cephalometric standards in each race is important. The purpose of this study was to determine the McNamara's Analysis standards in Iranian population and to compare them in Iranian men and ...
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Background and aim: The form of the facial skeleton and dental relationship is race specific, and estimating the cephalometric standards in each race is important. The purpose of this study was to determine the McNamara's Analysis standards in Iranian population and to compare them in Iranian men and women. Materials and Methods: In this Cross Sectional study cephalograms of 75 Iranian adults (18-35yrs) including 36 males and 39 females that represented Class I skeletal relationship, normal vertical pattern and space deficiency less than 3mm were selected Eleven indexes of McNamara Analysis were manually traced and analyzed. Mann-Whitney and Independent t-tests were used to compare values between males and females. Results: It was shown that there is significant difference in effective length of mid face, mandibular length and lower one third height between men and women (p<0.05). Our study findings was very similar to McNamara`s norms.Conclusion: Despite the larger jaw dimensions in Caucasian compared to Iranian ethnic group. McNamara analysis can be applied for Iranian population.
Barat Ali Ramazanzadeh; Mostafa Shahabi; Mohsen Merati
Abstract
Aim: Determination of overall and anterior Bolton ratios in people having normal occlusion in Iran and checking the effect of sexuality upon Bolton ratios in the aforementioned population and pinpointing the ability to apply normal quantities offered by Bolton in the Iranian population.Materials and ...
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Aim: Determination of overall and anterior Bolton ratios in people having normal occlusion in Iran and checking the effect of sexuality upon Bolton ratios in the aforementioned population and pinpointing the ability to apply normal quantities offered by Bolton in the Iranian population.Materials and methods: The study is a cross-sectional descriptive one by surveying study casts provided from 56 high school students (28 boys and 28 girls) having normal occlusions. Bolton ratios were considered in boys and girls separately. Statistical computations were conducted according to student t-test.Results: The total mesiodistal width of 12 permanent teeth and 6 anterior teeth in boys exceeded that of girls however this discrepancy has not statistically significant difference. The quantity of the overall and anterior Bolton ratios did not have statistically significant differences in boys and girls. The mean and standard deviation of the overall and anterior ratios in Iranian population were 91.58±2.03% and 77.73±3.17% which did not have statistically significant differences from the normal quantities offered by Bolton (P<0.05).Conclusion: The normal ratios offered by Bolton can be used in the Iranian boys and girls needing orthodontic treatments.
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.
