Prediction of width of un-erupted incisors, canines and premolars in a Ugandan population: a cross sectional study

Comparison of measured and predicted mesiodistal tooth-widths of 13-17 years old Kenyans: a descriptive cross-sectional study to develop a new prediction equation for use in the mixed dentition in a Kenyan population

BACKGROUND

The Tanaka and Johnson equation is commonly used in mixed dentition analysis. However, the analysis is based on  a Caucasian population making clinical decisions challenging when used in different ethnic groups. This study developed a prediction equation based on a Kenyan population.

DESIGN

A descriptive cross-sectional study done in 68 13-17 years old Kenyans of African descent in two boarding secondary schools. Alginate impressions were taken, study models obtained, and mesiodistal tooth-widths measured on upper and lower study models from the first molar to the contralateral first molar. Descriptive statistics, paired t-tests and independent t-tests were conducted and Pearson product-moment correlation coefficients calculated (p < 0.05).

RESULTS

The mean age was 13.78 years (SD ± 0.70), females were 59%. The mesiodistal tooth-widths of the permanent canines and premolars were different between males and females (p ˂ 0.1). The Tanaka and Johnston equation significantly under-estimated the mesiodistal tooth-widths of the permanent canines and premolars (p ˂ 0.05). The addition of lower first permanent molars to the permanent lower incisors provided higher correlation coefficients than the Tanaka Johnston equation.

CONCLUSIONS

A new equation that includes the permanent lower incisors and first permanent molars as predictor teeth seems to be more suitable for mixed dentition analysis for this Kenyan population. A larger study is needed to validate these findings.

The Importance of the Maxillary and Mandibular Incisors in Predicting the Canines and Premolars Crown Widths

Background

The purpose of the present study was to use the combined mesiodistal crown widths of the mandibular and maxillary incisors as predictors for the combined mesiodistal crown widths of mandibular and maxillary canines and premolars.

Materials and Methods

One hundred and twenty pairs of study models belong to 120 Iraqi adult subjects with normal dental and skeletal relations were included in the study. The crown widths of the mandibular and maxillary incisors, canines, and premolars were assessed at the maximum mesiodistal dimension on the dental casts using a digital electronic caliper with 0.01 mm sensitivity. The correlation between combined mesiodistal crown widths of the mandibular and the maxillary incisors and combined mesiodistal crown widths of mandibular and maxillary premolars and canines has been determined using Pearson's coefficient correlation test for each arch and gender. Using simple regression analysis, the equations predicting the widths of the mandibular and maxillary premolars and canines were established. The predicted and the actual mesiodistal crown width values have been compared with the use of a paired sample t-test.

Results

According to the findings of the present study, males had significantly wider teeth compared to females. Correlations between the measured parameters ranged from moderate to strong. A nonsignificant difference between actual and predicted mesiodistal crown widths was discovered.

Conclusions

With a high degree of accuracy, the combined mesiodistal widths of the maxillary and the mandibular incisors could be utilized for predicting the combined mesiodistal crown widths of the mandibular and maxillary canines and premolars.

Size estimation of unerupted canines and premolars using various independent variables: a systematic review

INTRODUCTION

Prediction of unerupted permanent teeth is an essential part of orthodontic diagnosis and treatment planning. This prediction is done by mixed dentition space analysis based on the estimation of mesiodistal dimensions of unerupted permanent canine and premolars from already erupted permanent teeth. Permanent mandibular incisors are most commonly used for prediction. Recent literature reveals that mandibular incisors are not accurate predictors and other independent variables have been introduced to make a more accurate and precise prediction. The objective of this paper was to evaluate the literature in light of a variety of independent variables and their predictive accuracy.

METHODS

Electronic databases such as MEDLINE, PubMed, Scopus, Embase, Web of Science, CINAHL Plus were searched to identify articles published until September 2021.

RESULTS

The search resulted in a total of 1098 articles, of which 24 papers met our inclusion criteria and were included in this review. Articles using permanent mandibular incisors only as a predictor were excluded during the eligibility assessment. The results show that various independent variables including mesiodistal and vestibulo-oral dimensions of permanent maxillary and mandibular incisors and molars, molar basal arch length, intermolar distance, maxillary and mandibular arch and gender have been used as predictors to more accurately determine mesiodistal width of unerupted canine and premolars in different populations.

CONCLUSION

Ethnic tooth size variations strongly emphasize the need to determine which independent variable gives a more accurate prediction of unerupted permanent teeth to develop a population-specific prediction model. This will play a significant role in managing space problems and developing malocclusions.

Applicability of moyer's probability tables in north indian population of 16-18 years old

Aims

To determine the applicability of Moyer's probability tables in North Indian population of 16-18 year olds and to formulate a new regression equation for the same group of population.

Setting and Design

Evaluative Study.

Methods and Material

1000 children aged 16-18 years were selected as sample for the measurement of mesiodistal widths of permanent mandibular incisors, maxillary and mandibular canines and premolars using study models. The recorded values were then subjected to statistical analysis.

Statistical Analysis Used

Software Package for Social Sciences (SPSS) software version 22.0.

Results

The actual widths of the canine and premolars showed highly significant differences in maxilla and in mandible (P < 0.001), compared to widths predicted by Moyer's probability table at 75^th percentile.

Conclusion

Moyer's mixed dentition analysis was not an accurate method for prediction in North Indian population as it showed overestimation of tooth sizes. Hence, new regression equation has been formulated for the same.

Predicting Canine and Premolar Mesiodistal Crown Diameters Using Regression Equations

OBJECTIVES

The current study aimed to predict the combined mesiodistal crown widths of maxillary and mandibular canines and premolars from the combined mesiodistal crown widths of maxillary and mandibular incisors and first molars.

MATERIALS AND METHODS

This retrospective study utilized 120 dental models from Iraqi Arab young adult subjects with normal dental relationships. The mesiodistal crown widths of all teeth (except the second molars) were measured at the level of contact points using digital electronic calipers. The relation between the sum mesiodistal crown widths of the maxillary and mandibular incisors and first molars and the combined mesiodistal crown widths of the maxillary and mandibular canines and premolars was assessed using Pearson's correlation coefficient test. Based on this relation, regression equations were developed to predict the sum widths of maxillary and mandibular canines and premolars; then, the predicted mesiodistal crown sum widths were compared with the actual one using a paired sample t-test.

RESULTS

Statistically, the predicted mesiodistal crown sum widths were nonsignificantly different from the actual ones.

CONCLUSIONS

The combined mesiodistal widths of maxillary and mandibular canines and premolars can be predicted successfully from the combined mesiodistal widths of the maxillary and mandibular incisors and first molars with a high degree of accuracy reaching to more than 86%.

Applicability of Different Mixed Dentition Analyses among Children Aged 11-13 Years in Chennai Population

Introduction

Mixed dentition is the stage where both primary and permanent teeth are present and hence is the time for developing occlusion. Mixed dentition analysis forms an essential part of an orthodontic assessment. Moyer's method which is commonly used for this analysis is based on data derived from a Caucasian population. Tanaka–Johnston developed prediction tables comparable with that of Moyer's from teeth measurement study models.

Aim

To test the reliability of Moyer's and Tanaka–Johnston's mixed dentition space analyses among children in Chennai.

Materials and methods

The mesiodistal measurements of the mandibular incisors, maxillary canines, and premolars were taken by measuring the greatest distance between the contact points on the proximal surfaces using a dental digital caliper set on dental casts of 1,000 children. Predicted values were obtained using Moyer's probability analysis at the 75th percentile and Tanaka–Johnston method. The statistical analysis for both sexes was done using Student's t test and unpaired t test.

Results

On application of the statistical analysis after the collection of data, it was found that the mean value in males was higher than the actual values in maxillary right and left sides when compared with the mandibular right and left sides while employing Moyer's method. The standard deviation (SD) was higher in the actual values when compared with the predicted values. Statistically significant values were obtained for the maxillary left side and the mandibular left side, but there was no statistical difference in the maxillary and mandibular right sides. Among females, it was found that the actual values had a higher mean value in the maxillary arch when compared with the mandibular arch than the values obtained when Moyer's formula was applied.

Conclusion

Both Moyer's and Tanaka–Johnson's mixed analyses when applied to children in Chennai tended to show that predicted values were higher than actual values with no significant differences observed among the regression equations.

How to cite this article

Ravinthar K, Gurunathan D. Applicability of Different Mixed Dentition Analyses among Children Aged 11–13 Years in Chennai Population. Int J Clin Pediatr Dent 2020;13(2):163–166.

New regression equations for mixed dentition space analysis in Nepalese mongoloids

BACKGROUND

Mixed dentition space analysis methods using regression equations, namely, Moyers' analysis and Tanaka-Johnston analysis are commonly used around the world. However, the applicability of these analyses among different racial groups have been questioned. The primary objective of this study was to assess the applicability of the Moyers' and Tanaka-Johnston analyses among Nepalese Mongoloids and to develop regression equations for the same population if needed.

METHODS

One hundred (50 males and 50 females) pre-treatment study models of the Nepalese Mongoloid patients undergoing orthodontic treatment were retrieved from the archives of the department of Orthodontics. The mesiodistal widths of mandibular incisors and widths of canines and premolars of all 4 quadrants were measured by a single investigator using a digital caliper to the nearest 0.01 mm. Predicted widths of canines and premolars were obtained using standard Moyers' and Tanaka-Johnston analyses and then compared with the measured widths.

RESULTS

The measured widths of canines and premolars were significantly different from the predicted widths obtained from Moyers' and Tanaka-Johnston analyses. Strong and positive correlations were found between the sum of mesiodistal widths of mandibular incisors and the sum of mesiodistal widths of canines and premolars in males (0.73 for maxillary arch and 0.68 for mandibular arch) and females (0.64 for maxillary arch and 0.79 for mandibular arch).

CONCLUSIONS

The Moyers' and Tanaka-Johnston analyses did not accurately predict the mesiodistal width of unerupted canines and premolars for Nepalese Mongoloid population. Hence, new regression equations have been developed for this population. However, validation studies should be conducted to confirm the applicability and accuracy of these equations.

Mixed dentition space analysis among Nepalese Brahmins/Chhetris

BACKGROUND

Mixed dentition space analysis forms an important part of orthodontic diagnosis and treatment planning. Regression equations are widely used for mixed dentition analysis which can vary among races. This study aimed to find out the new regression equation in estimating the size of unerupted canines and premolars for Nepalese Brahmins/Chhetris.

METHODS

Hundred Nepalese Brahmins/Chhetris (50 males and 50 females) who met our criteria were selected among the patients attending to the Orthodontic Out-Patient Department, Institute of Medicine, Kathmandu. The mesiodistal widths of all mandibular permanent incisors; maxillary and mandibular canines and premolars were measured and analyzed. The results were also compared with predicted values from the Moyers and the Tanaka and Johnston methods. Correlation and linear regression analyses were performed between the predicted and actual tooth sizes for Nepalese Brahmins/Chhetris and standard regression equations were developed.

RESULTS

No significant differences were observed when the sum of canine and premolars of one quadrant is compared between sides and sex. Significant and high positive correlations were found between the mandibular incisors and the combined mesiodistal widths of the canines and premolars for the maxillary (r = 0.72) and mandibular (r = 0.73) segments. Significant differences were observed between the measured values from this study and from Moyers (50 % and 75 % probability) and Tanaka-Johnston methods.

CONCLUSIONS

The equations and charts commonly used for North American children (50(th) or 75(th) percentile) did not accurately predict for our sample, so new regression equations and tables were developed for Nepalese Brahmins/Chhetris children.

Applicability of Two Universally Accepted Mixed Dentition Analysis on a Sample from Southeastern Region of Andhra Pradesh, India

BACKGROUND

Most of the universally accepted mixed dentition analyses are based on the data derived from northwestern European descent. However, the accuracy of these methods when applied to different ethnic population is questionable.

AIM

The present study is aimed to evaluate the applicability of Tanaka and Johnston (TJ) and Moyers (50(th) and 75(th) percentile) mixed dentition analysis in a sample from south-eastern region of Andhra Pradesh, India.

SUBJECTS AND METHODS

Study models were prepared from a sample of 100 patients (50 males and 50 females) in the age range of 13-15 years. The mesio-distal dimension of the teeth was measured using a Digital Vernier calipers. The actual values of permanent canine and premolars on the casts were compared with the predicted values from TJ and Moyers analysis. The values derived from this study were statistically analyzed using SPSS version 17.0 (IBM, Chicago, USA). Pearson's coefficients were used to evaluate the correlations between the groups of teeth.

RESULTS

Overestimated values were noticed in males and females of both arches with TJ equation; Males showed no significant difference at Moyers 50(th) percentile (50/100), in both the arches where as females showed higher values in mandibular arch and underestimated values in maxillary arch. At Moyers 75(th) percentile, overestimated values were noticed in males for both the arches whereas in females lesser values were observed.

CONCLUSION

As the values showed significant deviation from TJ and Moyers both at 50 and 75 percentile, its applicability to the present population is limited. So, new regression equations were derived.

Mixed dentition space analysis in a Sudanese population

OBJECTIVE

To test the applicability of the Tanaka and Johnston equation for prediction of the mesiodistal width of unerupted permanent teeth in a Sudanese population and to develop a new prediction equation for this specific population if necessary.

DESIGN

A descriptive, cross-sectional study.

SETTINGS

School-based study.

SUBJECTS AND METHODS

Two hundred and fifty subjects (118 males and 132 females) age 13 - 19 years were randomly selected from two public secondary high schools in Khartoum State. Mesiodistal widths of the upper and lower permanent canines, first and second premolars (CPM) as well as the mandibular permanent incisors (MPI) were measured manually on the dental casts using a digital caliper. The predicted values of the mesiodistal widths were statistically compared with the respective actual sum of the canine and premolars of the same quadrant.

RESULTS

Moderate correlation coefficients were found between the sum of the mesiodistal width of the MPI and the sum of the CPM in males (0.618 for mandibular arch and 0.626 for maxillary arch) and females (0.726 for mandibular arch and 0.680 for maxillary arch). A low coefficient of determination was recorded (0.45 and 0.48) in both jaws for combined genders.

CONCLUSIONS

The Tanaka and Johnston equations overestimated the actual mesiodistal width of CPM in both arches for males and females. New prediction equations with more accurate regression parameters were proposed for the Sudanese population.

A secondary analysis to determine variations of dental arch measurements with age and gender among Ugandans

BACKGROUND

Dental arch dimensions are useful in dental practice and in forensic odontology. Local data is essential because ethnic differences exist in dental arch dimensions. In the Ugandan population no studies had been done on dental arch dimensions. The objective of the current study was to determine the variations in dental arch dimensions with age and gender in a sample of dental casts from the Ugandan population.

METHOD

This was a secondary analysis of dental casts previously prepared using mandibular and maxillary arch impressions of 220 children (85 boys and 135 girls) aged 12-17 years recruited from schools in Kampala, Uganda. Dental arch dimensions for the maxilla and mandibular casts were taken using a digital vernier calliper. The data was analysed using the means based independent samples t test to obtain the descriptive statistics with regression analysis being used to obtain the regression coefficients and constants using STATA 12.

RESULTS

The overall maxillary dimensions were significantly smaller in females than males by 1.50 mm (95% CI -2.91 to -0.09, P = 0.04), controlling for age group. The overall dimensions of the mandible were also smaller in younger participants, though this was not statistically significant.

CONCLUSION

From this study we observed significant differences in arch dimensions between males and females that are of forensic value for this population. There is need for more study of the differences in arch dimensions with age using a larger and more age diverse study population.

Applicability of the Tanaka-Johnston and Moyers mixed dentition analyses in Northeast Han Chinese

OBJECTIVES

To assess applicability of the Tanaka-Johnston and Moyers prediction methods in a Han ethnic group from Northeast China and to develop prediction equations for this same population.

DESIGN

Cross-sectional study.

SETTING

Department of Orthodontics, School of Stomatology, Jiamusi University, Heilongjiang, China.

PARTICIPANTS

A total of 130 subjects (65 male and 65 female) aged 16-21 years from a Han ethnic group of Northeast China were recruited from dental students and patients seeking orthodontic treatment. Ethnicity was verified by questionnaire.

MATERIAL AND METHODS

Mesio-distal tooth width was measured using Digital Vernier calipers. Predicted values were obtained from the Tanaka-Johnston and Moyers methods in both arches were compared with the actual measured widths. Based on regression analysis, prediction equations were developed.

RESULTS

Tanaka-Johnston equations were not precise, except for the upper arch in males. However, the Moyers 85th percentile in the upper arch and 75th percentile in the lower arch predicted the sum precisely in males. For females, the Moyers 75th percentile predicted the sum precisely for the upper arch, but none of the Moyers percentiles predicted in the lower arch.

CONCLUSIONS

Both the Tanaka-Johnston and Moyers method may not be applied universally without question. Hence, it may be safer to develop regression equations for specific populations. Validating studies must be conducted to confirm the precision of these newly developed regression equations.

Mixed dentition space analysis in kodava population: a comparison of two methods

AIMS

To evaluate the reliability of Tanaka and Johnston and Moyer's (75th percentile) mixed dentition prediction methods in Kodava population sample, to formulate regression equations for predicting the mesiodistal widths of unerupted canines and premolars and to construct probability tables for the Kodava population.

SETTINGS AND DESIGN

Data was obtained from Kodava subjects visiting the clinics for routine dental check up.

MATERIALS AND METHODS

Dental models of 30 male and 30 female Kodava subjects (age range is 16 - 23 yr) were used. Teeth measured included mandibular permanent incisors, maxillary and mandibular permanent canines, first and second premolars. Digital caliper calibrated to 0.01mm was used to record mesiodistal dimensions. The actual teeth measurements were then statistically compared with the predicted values derived from the Tanaka and Johnston's equations and Moyers probability tables at the 75(th) percentile.

STATISTICAL ANALYSIS USED

Descriptive statistics including means, standard deviations were calculated for the actual and predicted tooth sizes. Student's t-tests were performed to compare the differences between the measured mesiodistal widths of canine, first and second premolars and the predicted values derived from Moyers. Correlation and regression analysis were performed to formulate standard regression equations.

RESULTS

Tanaka and Johnston prediction equations overestimated the mesiodistal widths of permanent canines and premolars in both the arches. Moyers 75(th) percentile also overestimated the actual measurements except for the maxillary arch in female subjects. The percentage of overestimation was more for Tanaka - Johnston prediction method than that of Moyers (75(th) percentile). Correlation and regression analysis were performed between the predicted and actual tooth size and standard regression equations were developed for the Kodava population. Probability tables were also constructed from the data obtained.

CONCLUSION

The data from present study illustrates the limitation of Tanaka and Johnston regression equations and Moyer's (75(th) percentile) chart when applied to Kodava population. From this data, regression equations and probability tables were derived for tooth size prediction for Kodava population. This would be more accurate when applied to local children of Kodava community.

A new proposed regression equation for mixed dentition analysis using the sum of permanent mandibular four incisors and first molar as a predictor of width of unerupted canine and premolars in a sample of North Indian population

OBJECTIVE

The objective of this study was to establish a new regression equation for North Indian and to compare and correlate the predicted width of unerupted canine and premolars obtained from the proposed regression equation of the present study in the North Indian population sample, Moyer's prediction table and also from Melgaco regression equation with the actual width; in order to check the applicability of various methods of mixed dentition analysis for the North Indian population.

MATERIALS AND METHODS

The sample consisted of 200 dental casts obtained from the North Indian patients and students which consists of 100 males and 100 females with the average age of 20.12 ± 4.70 years for males and 19.54 ± 3.16 years for females. Mesiodistal tooth widths of mandibular arch from permanent right first molar to left first molar were measured with an electronic digital caliper. Student t-test was used for comparison and Pearson's correlation coefficient was used to correlate the actual sum and the predicted width of the permanent mandibular canines and premolars obtained from various methods.

RESULTS

The difference between the actual and predicted width was statistically insignificant using the regression equation obtained for the North Indian sample population (correlation r = 0.78) in contrast to the significant difference with predicted width obtained from Melgaco equation (r = 0.61) and Moyer's prediction table (r = 0.42).

CONCLUSIONS

A new proposed regression equation for the North Indian population was established. Amongst the three regression equations devised, the proposed regression equation formulated in the present study; gave the most accurate results confirming racial variation in tooth size. This method is considered as an easy and practical way to predict the size of unerupted canines and premolars.