Predicting the size of unerupted canines and premolars of the maxillary and mandibular quadrants in an Iranian population

The aim of this investigation was to examine the accuracy of Moyers probability tables and the Tanaka and Johnston prediction equations in predicting the size of unerupted canines and premolars of the maxillary and mandibular quadrants in an Iranian population and to derive a standard formula for it. METHODS: Out of a sample of 280 subjects, 50 (25 males and 25 females) were selected by specific inclusion criteria. An electronic digital caliper was used to read the nearest 0.01 mm. The teeth measurements derived were compared with those predicted from Tanaka Johnston equations and Moyers probability tables and then standard regression were developed. RESULTS: Tanaka and Johnston regression equations overestimate the mesiodistal width of permanent canines and premolars. There were no statistically significant differences between actual mesiodistal width of canines and premolars and the predicted width from Moyers charts at 65% for the lower and upper arches in male subjects and for the lower arch in females but none of the probabilities has good accuracy for the upper arch in females. For the newly developed regression equations, the correlation coefficients between the sum of the mandibular incisors and the sum of the canine and premolars were 0.709 (for lower) and 0.539 (for upper) in subjects. CONCLUSIONS: Tanaka and Johnston overestimate the actual size for Iranian teeth widths. Moyers method can be used at 65% probability level for male subjects and at the 75% and 85% level for upper arch and the 50% and 65% level for lower arch in female subjects.     

Prediction of mesiodistal canine and premolar tooth width in a sample of Peruvian adolescents

Authors – Flores‐Mir C, Bernabé E, Camus C, Carhuayo MA, Major PW Objectives – To compare the predicted tooth width measurements of permanent canine and premolars from Tanaka–Johnston regression equations and Moyers probability tables with the in situ measurements in a sample of Peruvian adolescents. Design – Cross‐sectional. Setting and sample population – Trujillo, Peru; 248 dental casts were measured using a sliding caliper with a Vernier scale rounded to 0.1 mm. Results – Tanaka–Johnston regression equations were not precise, except for the upper arch in the male sample. For females, the Moyers 95th percentile in the upper arch and the 65th percentile in the lower arch predicted the sum precisely. For males, the Moyers 65th percentile for the lower arch predicted the sum precisely, but none of the Moyers percentiles provided precise prediction in the upper arch. Conclusions – Using tooth width prediction methods from a different racial origin could create an under‐ or overestimation of the actual combined canine and premolar tooth width, although their clinical significance is disputable.     

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

AIMS: To test the reliability of the Moyers charts and the Tanaka and Johnston equations in Jordanians and to derive coefficients of correlation between the combined mesiodistal widths of the four permanent mandibular incisors and the combined widths of the canine and premolars of the maxillary and mandibular quadrants. METHODS: The dental models of the dentition of 130 male and 96 female Jordanian subjects (age range is 14-16 years) with complete permanent dentition were randomly selected. The mesiodistal width of the four permanent mandibular incisors, maxillary and mandibular canines, and premolar teeth were measured using a vernier gauge caliper to the nearest 0.1 mm. The actual teeth measurements were then compared with the predicted values derived from the Tanaka and Johnston equations and Moyers probability tables. Correlation and linear regression analyses were performed between the predicted and actual tooth size for Jordanian children and standard regression equations were developed. RESULTS: Except for the maxillary arch in male subjects, Tanaka and Johnston regression equations underestimated the mesiodistal widths of permanent canines and premolars. On the other hand, there were no statistically significant differences between actual mesiodistal widths of canines and premolars and the predicted widths from Moyers charts at the 65% and 75% level for the lower and upper arches in male subjects and at the 85% level for the upper and lower arches in female subjects. For the newly developed regression equations, the correlation coefficients between the sum of the mandibular four incisors and the sum of the canine and premolars were 0.60 (for lower) and 0.51 (for upper) in male subjects and 0.59 and 0.64, respectively, in female subjects. CONCLUSIONS: (1) Tanaka and Johnston prediction method was not accurate when applied to a Jordanian population. (2) Moyers method for prediction can be used for Jordanian children at different probability levels for male and female subjects.     

The lower incisors as a predictor for the size of unerupted canine and premolars in the Iranian ethnicity

The purpose of this study was to find the correlation coefficients between the mesiodistal widths of the permanent mandibular incisors and the permanent canine and premolars for each quadrant and establish a regression equation for prediction of the sum of canine and premolars based on the dimension of the lower incisors. 90 patients 12–20 years old (45 females and 45 males) were selected. The mesiodistal crown diameters of the permanent teeth were measured. The correlation coefficients between the permanent mandibular incisors and the permanent canine and premolars sizes varied from 0.63 to 0.8. An Iranian mixed dentition analysis based on the Tanaka and Johnston method was constructed with linear regression equations; for maxillary arch y = 6.3 + 0.65x (SEE = 0.8 mm) and for mandibular arch y = 5.1 + 0.67x (SEE = 0.8 mm). No significant sexual dimorphism was found in tooth sizes. This study revealed that Iranian population has smaller teeth than white North American. We found that prediction equations of Tanaka and Johnston or Moyers charts cannot accurately predict the size of buccal segment in Iranian population.     

Mixed dentition space analysis in Egyptian children

This study was done to examine the applicability of the Tanaka and Johnston and Moyers’ methods of prediction in Egyptian population and to develop a new prediction method for this specific population if necessary. A total of 325 Egyptian students 145 female, 180 male, mean age 14.4 years, SD±1.1 years were randomly selected from 10 preparatory and secondary schools in Mansoura city, Dakahlia governorate, Egypt during the academic year 2008–2009. The mesiodistal crown diameters of the permanent teeth were measured and compared with the predicted values derived from the Tanaka and Johnston's equations and from Moyers’ probability tables at 35%, 50% and 75%. Significant sexual dimorphism was found in tooth sizes. There were significant differences between the actual measurements and that derived from the Tanaka and Johnston's equation and Moyers’ tables. New linear regression equations were derived for both genders to allow accurate tooth size prediction in Egyptians. The correlation coefficients between the total mesiodistal width of the mandibular permanent incisors and that of the maxillary and mandibular canines and premolars were found to be 0.78 and 0.89 in male and 0.63 and 0.87 in female, respectively. It can be concluded that there is a limitation in the application of the Tanaka and Johnston's and Moyers’ prediction methods to Egyptian population. The developed prediction equation is more accurate for predicting the mesiodistal widths of unerupted canine and premolars of Egyptian population.     

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 analysis in a Moroccan population.

The aims of this study were to produce odontometric data for a Moroccan population, to test Tanaka and Johnston and Moyers methods, to derive regression equations and elaborate a specific orthodontic prediction table for Moroccan children. 50 dental casts of Moroccan students (25 males, 25 females, mean age 22.6 years sd 1.35) were used to perform measurements of the greatest mesiodistal widths of all mandibular and maxillary canines and premolars and mandibular incisors with an orthodontic calliper. Significant sexual dimorphism was found in tooth sizes (p = .001). The study revealed close relationships between the total mesiodistal widths of the mandibular permanent incisors and that of the maxillary and mandibular canines and premolars. The correlation coefficients (r) and the coefficient of determination (R2) were better sexes combined for the maxilla (r = 0.60 ; R2 = 0.36 ) and for the mandible (r = 0.61 ; R2= 0.37). The regression equations elaborated for males and females were used as a basis for establishing an orthodontic prediction table for Moroccan children.     

Tanaka-Johnston mixed dentition analysis for southern Chinese in Hong Kong

OBJECTIVE: To compare the prediction of unerupted permanent canine and premolar size of a comparable sample size of southern Chinese population with that of the study of Tanaka and Johnston. MATERIALS AND METHODS: Teeth on study casts of an unselected sample from a 12-year-old Hong Kong Oral Health Survey of 12-year-old children (n = 459; 295 males and 164 females) were measured in the mesiodistal dimension. A Chinese mixed dentition analysis based on the Tanaka and Johnston method was constructed with linear regression equations for prediction of the mesiodistal widths of unerupted canines and premolars. Results: Sexual dimorphism was evident between southern Chinese 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 southern Chinese children, halve the sum of the mesiodistal dimensions of the four mandibular incisors and add the respective constants for males (upper, 11.5; lower, 10.5) or females (upper, 11.0; lower, 10.0).     

Mixed dentition analysis in a Jordanian population

OBJECTIVE: To examine the applicability of the Tanaka and Johnston method of prediction in a Jordanian population and to develop a new prediction method for this specific population if necessary. MATERIALS AND METHODS: Three-hundred and sixty-seven Jordanians (193 female, 174 male, mean age 15.5 years) were randomly selected to represent 0.1% of 10th grade schoolchildren from Amman, Jordan. The mesiodistal crown diameters of the permanent teeth were measured and compared with the predicted values derived from the Tanaka and Johnston equations. RESULTS: Significant sexual dimorphism was found in tooth sizes. The correlation coefficients between the total mesiodistal width of the mandibular permanent incisors and that of the maxillary and mandibular canines and premolars were found to be 0.60 and 0.66, respectively. There were significant differences between the actual measurements and measurements derived from the Tanaka and Johnston equations. New linear regression equations were derived for both genders to allow tooth size prediction in Jordanians. CONCLUSIONS: There is a limitation in the application of the Tanaka and Johnston's prediction method to a Jordanian population. It is important to use separate equations for male and female patients.     

Comparison of three nonradiographic methods of mixed dentition analysis in cleft lip and palate patients.

PURPOSE: The purpose of this study was to investigate whether the application of mixed dentition analyses in cleft lip and palate patients differed from noncleft patients and to investigate which method provided the most accurate prediction in cleft lip and palate patients. METHODS: Study casts of 30 cleft lip and palate patients and 30 noncleft patients were used in this study. Each patient had dental casts at two stages of dental development. The methods compared included the Moyers, the Tanaka & Johnston (T/J) and the Boston University (BU) prediction methods. RESULTS: Analyses for both groups indicated that the predicted values yielded by each method were significantly different from one another but were all significantly correlated with actual tooth size. Moyers 50% and BU had the smallest mean difference values and no significant difference between the predicted and actual values for both cleft and noncleft control groups. CONCLUSIONS: Types of cleft had no effect on the size of the mandibular permanent canines and premolars. The application of mixed dentition analyses in cleft lip and palate patients does not differ from noncleft patients. Both Moyers 50% and the BU method have high accuracy and correlation in prediction of unerupted teeth in both groups.     

Prediction of the size of un-erupted permanent cuspids and bicuspids in a Saudi sample: a pilot study

The purpose of this study was to produce an estimated equation for the prediction of unerupted cuspids and bicuspids for the Saudi population. In this study, dental casts of 65 Saudi subjects (37 males and 28 females) were used. The subjects' age ranged from 18 to 25 years. The mesiodistal width of all permanent teeth was measured. The data was subjected to regression analysis. Results showed the Tanaka and Johnston equations overestimate the predicted tooth width of the un-erupted cuspids and bicuspids in Saudis. Results showed the predicted tooth width of Saudis (males and females) is closer to the 50% level of confidence in Moyer's chart. Multiple regression equations were estimated including the sex factor. Accordingly, two equations were estimated for the prediction of the tooth width of the un-erupted cuspids and bicuspids for the Saudi males and females. Based on the results, it can be concluded the 50% data is more accurate than the commonly used percentage Moyer's table (75%) when both sexes are combined. Further studies are needed to confirm the findings of this study.     

Applicability of three tooth size prediction methods for white Brazilians

The objectives of this study were to evaluate the applicability of the methods of Moyers; Tanaka and Johnston; and Bernabé and Flores-Mir to Brazilian individuals and to propose new regression equations using the lower four permanent incisors as predictors for the sum of the widths of the lower permanent canine and premolars. Five hundred dental study casts (250 male and 250 female white patients) were used. The methods of Moyers and Tanaka and Johnston were tested on a sample consisting of 240 female and 223 male patients. The method of Bernabé and Flores-Mir and the new regression equations were based on the complete sample. At the 50th and 75th percentile levels, Moyers' tables tended to underestimate the actual sum of the lower permanent canine and premolars for male and female samples, with statistically significant differences. Although the same statistical significant differences were found when Tanaka and Johnston's and Bernabé and Flores-Mir's methods were used, these differences were not clinically relevant. The new regression equations proposed demonstrate similar correlation and determination coefficients to those found in other studies based on the lower four permanent incisors as predictors. Validating studies (based on similar samples) must be conducted to confirm the applicability and precision of the proposed new regression equations.     

Tooth width predictions in a sample of Black South Africans.

Space analysis during the mixed dentition requires prediction of the mesiodistal widths of the unerupted permanent canines and premolars and prediction tables and equations may be used for this purpose. The Tanaka and Johnston prediction equations, which were derived from a North American White sample, is one example which is widely used. This prediction equation may be inapplicable to other race groups due to racial tooth size variability. Therefore the purpose of this study was to derive prediction equations that would be applicable to Black South African subjects. One hundred and ten pre-treatment study casts of Black South African subjects were analysed from the Department of Orthodontics' records at the University of Limpopo. The sample was equally divided by gender with all subjects having Class I molar relationship and relatively well aligned teeth. The mesiodistal widths of the maxillary and mandibular canines and premolars were measured with a digital vernier calliper and compared with the measurements predicted with the Tanaka and Johnston equations. The relationship between the measured and predicted values were analysed by correlation and regression analyses. The results indicated that the Tanaka and Johnston prediction equations were not fully applicable to the Black South African sample. The equations tended to underpredict the male sample, while slight overprediction was observed in the female sample. Therefore, new equations were formulated and proposed that would be accurate for Black subjects.     

Individual-based prediction of the size of the supporting zones in the permanent dentition

The aims of this individual-based study were 1. to assess the actual space requirements of the permanent canines and premolars, 2. to test the reliability of the Moyers method in predicting a space deficiency at the 75% confidence level and 3. to try to find a reliable unitary prediction value (=unitary value) as a possible substitute for the calculated Moyers values. Dental cast measurements were taken of the permanent dentition of 100 females and 100 males. The average sum of the widths of the maxillary and mandibular permanent canines and premolars was 20.8 mm (17.3 to 24.3 mm). The Moyers method could predict a maxillary space deficiency in 77.5% and a mandibular space deficiency in 65.5% of the subjects. The unitary value of 22.0 mm made it possible to predict a space deficiency in 83.5% of the subjects. The unitary value thus had a higher confidence level (83.5%) than the 75% level stated by Moyers and might thus substitute the calculated Moyers values. Furthermore, the unitary value is easy and quick to handle.

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Vorhersage der Größe der Stützzonen Im blelbenden Gebiß auf individueller BasisVergleich der Moyers-Methode mit einem prognostischen Einheitswert

Zusammenfassung Die Ziele dieser individuell bezogenen Studie waren 1. die Ermittlung des tatsächlichen Platzbedarfes der bleibenden Zähne in den Stützzonen (=Stützzonenbreiten), 2. die Überprüfung der Zuverlässigkeit der Moyers-Methode zur Vorhersage eines Platzmangels auf dem Niveau 75%iger Sicherheit und 3. der Versuch, einen einheitlichen Prognosewert (=Einheitswert) als möglichen Ersatz berechneter Moyers-Werte zu finden. Vermessen wurden 200 Gebißmodelle der permanenten Dentition von 100 weiblichen und 100 männlichen Probanden. Die durchschnittliche tatsächliche Stützzonenbreite für Ober- und Unterkiefer betrug 20,8 mm (17,3 bis 24,3 mm). Die Moyers-Methode konnte einen Platzmangel im Oberkiefer bei 77,5% und im Unterkiefer bei 65,5% der Probanden vorhersagen. Der Einheitswert von 22,0 mm ermöglichte die Vorhersage eines Platzmangels bei 83,5% der Probanden. Hiermit lag beim Einheitswert das Sicherheitsniveau der Prognose eines Platzmangels mit 83,5% oberhalb des von Moyers angegebenen Wertes von 75%, und der Wert könnte somit die berechneten Moyers-Werte ersetzen. Dazu kommt beim Einheitswert die einfache Anwendbarkeit mit geringem Zeitaufwand.

     

北方汉族人Tanaka-Johnston预测方程研究

目的分析北方汉族青少年下颌切牙总宽度与尖牙、双尖牙总宽度之间的相关性,探寻适合目标人群的Tanaka-Johnston预测方程。方法从就诊于首都医科大学口腔医学院正畸科的病例中选取记存模型127副。研究下颌切牙总宽度与尖牙、双尖牙总宽度之间的相关性,建立北方汉族人的Tanaka-Johnston预测方程,并评价不同预测方程的准确性。结果男性组下颌切牙总宽度与上、下颌尖牙双尖牙总宽度之间相关系数r为0.71、0.77,女性组r为0.50、0.56。除本研究得出的方程外,其他预测方程普遍存在低估倾向。男性组实测值与预测值之差小于1mm的以北方汉族人方程上颌84%、下颌88%为最高;女性组以成都汉族人方程上颌74%,下颌81%为最高。结论与女性相比,男性下颌切牙总宽度与尖牙、双尖牙总宽度存在较强的正相关关系。预测准确度最高的方程分别为:男性上颌Y=11.8+0.5X,下颌Y=10.9+0.5X;女性上颌Y=11.1+0.5X,下颌Y=10.0+0.5X。     

New regression equations for predicting the size of unerupted canines and premolars in a contemporary population

The determination of a tooth-size to arch-length discrepancy in the mixed dentition requires an accurate prediction of the mesiodistal widths of the unerupted permanent teeth. This is an essential factor in treatment planning. The aim of this study was to validate Tanaka and Johnston's analysis on 600 Syrian patients aged 14-22 years. Tanaka and Johnston's tables, equations, and approximations were modified in order to improve the accuracy of the prediction. The correlation coefficients found between the size of the permanent mandibular central incisors and maxillary first molars (31, 41, 16, and 26) and the maxillary and mandibular canines and premolars were high (r = .72 and .74, respectively). New, more accurate prediction tables applicable at earlier ages, and new regression equations were constructed. In addition, new easier approximations were developed to allow the prediction of the size of the unerupted maxillary canines and premolars by adding 6 mm to the half-widths of teeth 31, 41, 16, and 26. The analogous prediction of the size of the unerupted mandibular canines and premolars was obtained by adding 5.5 mm to the half-widths of same teeth, 31, 41, 16, and 26.     

Mixed dentition space analysis for Indonesian Javanese children

The purposes of this study were to determine the applicability of Moyers and Tanaka-Johnston prediction methods for Indonesian Javanese children, and to develop new regression equations for predicting the size of the canine-premolar segment based on the normative standard of mesio-distal crown diameters of the permanent teeth in Indonesian children. Two hundred and eighty five sets of dental casts of the permanent dentition were obtained from Indonesian Javanese children in Yogyakarta, Indonesia during 2000– 2001. There were 143 males and 142 females aged 11.1 to 14.9 years. The mesio-distal crown diameters were measured with calipers to an accuracy of 0.05 mm. The statistical analyses were performed using computer software (SPSS 9.0 for Windows). This study confirmed that the use of Moyers and Tanaka-Johnston prediction methods for mixed dentition analysis among Indonesian Javanese children were unsuitable. Both methods underestimated the size of canine-premolar segments, with exception of the Tanaka-Johnston method in females. The combination of maxillary first molars and mandibular lateral incisors (

) showed relatively higher correlation with the actual size of ∑3 4 5. The development of new linear regression equations with predictor

for predicting the size of the canine-premolar segment was based on the normative standard of mesio-distal crown diameters of permanent teeth in Indonesian Javanese children. The newly developed regression equations are more accurate than the regression equation that uses predictor

for mixed dentition analysis among Indonesian Javanese.     

Mixed dentition space analysis in a Thai population

This study produced simple linear regression equations to be used for mixed dentition space analysis for males and females, and sexes pooled in a population living in northeastern Thailand. Measurements of teeth were made to within 0.01 mm on the dental casts of 215 boys and 215 girls (mean age 15.7 years). All dentitions were required to be free of any signs of dental pathology or anomalies. It was found that males had significantly larger teeth than females as represented by summations of mandibular incisor, canine, and premolar widths. ANOVA of regression indicated a close relationship between mandibular incisor summation and corresponding summations of canine and premolars. The low coefficients of determination (r2) of the regressions ranged between 0.29 and 0.42, and were higher for females than males, which might be attributable to the ethnic diversity of the sampled population. The regression equations produced predictions of mesio-distal width summations for maxillary and mandibular canine, and premolar arch segments that were slightly different from other reported Asian studies. Moyers' prediction tables at the 50th percentile were found to under-estimate tooth size summation compared with the present investigation. The predictions from simplified regression equations matched well with those of this study for sexes pooled, and for males and females separately.     

A comparison of four methods of predicting arch length.

1. Four arch length prediction equations (Nance, Johnston-Tanaka, Moyers, and Hixon-Oldfather) were compared by examining pretreatment casts, pretreatment intraoral radiographs, and posttreatment casts of forty-one patients of mixed-dentition age. 2. A comparison of correlation coefficients and slopes of the predicted arch length versus the actual arch lengths revealed that the Hixon-Oldfather method conformed closest to the ideal. 3. No combination of the four methods produced a more accurate equation than the single most accurate method. 4. Neither the sex of the patient nor the type of occlusion affected the prediction accuracy of any of the four equations. 5. All methods tend to overpredict the arch length size by 1 to 3 mm., with the exception of the Hixon-Oldfather equation, which underpredicted by approximately 0.5 mm. 6. An analysis of the intrainvestigator error showed a very low standard error of estimate for individual tooth measurements and for the prediction values. 7. A variance analysis showed that most of the variation was due to arch length (85%), a slight amount was due to the prediction method (8%), and 6% of the variation was due to the rater. 8. A low correlation was found between space available versus actual discrepancy and space available versus actual arch length. 9. High correlation coefficients were found for the predicted arch lengths when compared with the actual arch lengths. As expected, the correlation coefficients for the predicted widths of only the canines and premolars compared with the actual widths were not quite as high.