Comparison of the different methods of width estimation in unerupted canine and premolars.

BACKGROUND: There are different methods for determining the required space for unerupted teeth. However, the accuracy of these techniques varies depending on ethnic differences. Therefore, the current study was performed to compare the accuracy of four methods for estimating the mesiodistal width of unerupted canines and premolars in a population of northern Iran. METHODS: The present cross-sectional study was conducted on 50 pairs of dental casts of patients aged 12-24 years old. The mesiodistal width of the teeth was measured with a digital caliper by two observers (ICC < 0.9), and the mean value was recorded. The space required for eruption of canines and premolars was obtained by the Tanaka-Johnson formula and the Moyers tables and compared with the actual value by paired t test. RESULTS: The Tanaka-Johnson formula had overestimation in the maxilla and mandible, which was statistically significant (p < 0.001). The values obtained from the Moyers tables in different confidence levels were not accurate. However, the 65% level for the mandible had almost no difference from the actual value (P = 0.996 and r2 = 0.503). Furthermore, linear regression was obtained based on the total mesiodistal width of the maxillary first molar and mandibular central incisor (maxilla: Yx= 0.613X + 2.23 and mandible: Ym= 0.618X + 1.6) and the total mesiodistal width of the mandibular first molar and maxillary central incisor in each jaw (maxilla: Yx = 0.424X + 5.021 and mandible: Ym = 0.447X + 3.631). CONCLUSION: The Tanaka-Johnson method was overestimated in the population of northern Iran. The 85% and 75% confidence levels of the Moyers table have the best clinical results for the maxilla and mandible, respectively. Regression based on maxillary first molars and mandibular central incisors has better results.

Accuracy of Model Estimation versus Tanaka and Johnston Arch Length Analysis.

OBJECTIVES: This study examines how accurate pediatric dentists are at estimating dental arch lengths by comparing their model estimations (guesstimating the arch length without measuring) to the Tanaka and Johnston mixed dentition arch length analysis. STUDY DESIGN: This study consisted of two parts, a survey of practitioners and a model estimating and measuring component. The survey was designed and given to 44 pediatric dentists to determine how many were practicing orthodontics and using arch length analyses routinely. Then 18 pediatric dentists and 13 pediatric dental residents examined 20 sets of mixed dentition models and estimated how much space was available. These estimations were compared to the calculated gold standard, the Tanaka and Johnston arch length analysis of the same models. RESULTS AND CONCLUSIONS: More than half of the dentists surveyed that practice comprehensive orthodontics use arch length estimates. Pediatric dentists and pediatric dental residents are just as good as each other at estimating arch length. Pediatric dentists and pediatric dental residents underestimated arch length by -3.6 and -3.1 mm, respectively. More research needs to be done to determine if model estimation is a clinically acceptable way to judge arch length.

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.

Equation for Tooth Size Prediction from Mixed Dentition Analysis for Taiwanese Population: A Pilot Study.

BACKGROUND: In mixed dentition analysis, estimation of the mesiodistal width of unerupted permanent canines and premolars is essential for successful diagnosis and treatment planning. The present study aimed to develop a simple linear equation to predict permanent tooth sizes from mixed dentition analysis for Taiwanese people. METHODS: The sample comprised 200 dental casts, derived from Taiwanese patients (100 males and 100 females; age, 12-35 years). Mesial distal tooth widths were measured in dental casts with a digital caliper. A student's t-test was conducted to detect tooth size correlations with gender-specific differences, as well as intra-arch counterparts. Standard linear regression was conducted to develop a simple equation representing predictions of canine-premolar relationships. RESULTS: All teeth were not significantly different between the left and right sides, regardless of gender and upper or lower arches. In terms of types of teeth, males had larger tooth dimensions in both arches than females. New regression equations for estimating the dimensions of the unerupted canines and premolars in the Taiwanese population were developed. CONCLUSIONS: Using a sample of Taiwanese people, new models derived for females and males separately were developed, which should provide highly accurate predictions for unerupted canines and premolars in the Taiwanese population.

Applicability of Boston University approach for prediction of mesiodistal width of canines and premolars in the primary schoolchildren of rural Bengaluru: An in vivo study.

INTRODUCTION: Boston University (BU) approach is a method for early prediction of unerupted permanent mandibular teeth widths based on the mesiodistal widths (MDWs) of primary mandibular canines and first molars. The present study was conducted to test the validity of BU approach by comparing it with Tanaka-Johnston (T/J) approach in the contemporary population. AIMS AND OBJECTIVE: The aim of the study was to determine the applicability of BU approach for prediction of the MDWs of canines and premolars in the primary schoolchildren of rural Bengaluru. MATERIALS AND METHODS: The study was conducted in 100 healthy schoolchildren of rural Bengaluru aged between 7 and 11 years. The MDWs of canines and premolars were predicted using both T/J and the considered BU approaches for all the children and were compared. RESULTS: The correlation coefficient showed a statistically significant correlation between the predicted tooth size from the two predicted methods in the upper and lower arches (P < 0.001), with Pearson's correlation coefficient showing the very strong positive relationship (r = 0.7). Significant differences were seen between the mean predicted width of canines and premolars by both the approaches (P < 0.001). CONCLUSION: In spite of the limitations, we recommend the use of BU approach to predict arch length-tooth material discrepancy at an early age and to get at least an approximate estimation of the required space. We also advocate the necessity of further research on this approach prospectively.

Corrected and Republished: Applicability of Boston University approach for prediction of mesiodistal width of canines and premolars in the primary schoolchildren of rural Bengaluru: An in vivo study.

INTRODUCTION: Boston University (BU) approach is a method for early prediction of unerupted permanent mandibular teeth widths based on the mesiodistal widths (MDWs) of primary mandibular canines and first molars. The present study was conducted to test the validity of BU approach by comparing it with Tanaka-Johnston (T/J) approach in the contemporary population. AIMS AND OBJECTIVE: The aim of the study was to determine the applicability of BU approach for prediction of the MDWs of canines and premolars in the primary schoolchildren of rural Bengaluru. MATERIALS AND METHODS: The study was conducted in 100 healthy schoolchildren of rural Bengaluru aged between 7 and 11 years. The MDWs of canines and premolars were predicted using both T/J and the considered BU approaches for all the children and were compared. RESULTS: The correlation coefficient showed a statistically significant correlation between the predicted tooth size from the two predicted methods in the upper and lower arches (P < 0.001), with Pearson's correlation coefficient showing the very strong positive relationship (r = 0.7). Significant differences were seen between the mean predicted width of canines and premolars by both the approaches (P < 0.001). CONCLUSION: In spite of the limitations, we recommend the use of BU approach to predict arch length-tooth material discrepancy at an early age and to get at least an approximate estimation of the required space. We also advocate the necessity of further research on this approach prospectively.

Primary Dentition Analysis: Exploring a Hidden Approach.

BACKGROUND: Accurate prediction of the mesiodistal widths (MDWs) of canines and premolars in children with primary dentition facilitates interception of malocclusion at an early age. Boston University (BU) approach is one, i.e., based on primary teeth for predicting canine and premolar dimensions. AIM: To predict the canine and premolar dimensions, in the contemporary population, using BU approach and compare with the values obtained using Tanaka-Johnston (T/J) approach. DESIGN: Children in the age range of 7-11 years with presence of all permanent mandibular incisors and primary maxillary and mandibular canines and first molars were included in the study. Those with interproximal caries or restorations, abnormalities in shape or size and history of orthodontic treatment were excluded. Impressions of both arches were made using irreversible hydrocolloid and poured with dental stone. The MDWs of the required teeth were measured on the models using electronic digital vernier caliper from which widths of permanent canines and premolars were predicted using both T/J and BU approaches. RESULTS: Statistically significant (p = 0.00) positive correlation (r = 0.52-0.55) was observed between T/J and BU approaches. A statistically significant (p = 0.00) strong positive correlation (r = 0.72-0.77) was observed among girls, whereas boys showed a statistically nonsignificant weak positive correlation (r=0.17-0.42) based on gender. CONCLUSION: Boston University approach can be further studied prospectively to make it possible as a prediction method of permanent tooth dimensions for children in primary dentition stage. How to cite this article: Nuvvula S, Vanjari K, Kamatham R, Gaddam KR. Primary Dentition Analysis: Exploring a Hidden Approach. Int J Clin Pediatr Dent 2016;9(1):1-4.

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.

Evaluation of validity of Tanaka-Johnston analysis in Mumbai school children.

INTRODUCTION: Estimation of the mesiodistal dimensions of the unerupted canines and premolars in the early mixed dentition is a necessary diagnostic aid in space management. Tanaka-Johnston analysis was developed for North American children. Anthropological study reveals that tooth size varies among different ethnicities. The present study was performed to evaluate the validity of Tanaka-Johnston method of mixed dentition arch analysis in Mumbai school children. AIMS: (1) To determine the correlation between the sum of the mesiodistal widths of the permanent mandibular incisors and combined mesiodistal widths of the permanent mandibular and maxillary canines and premolar in Mumbai school children. (2) To examine the applicability of Tanaka-Johnston method of prediction. MATERIALS AND METHODS: Dental casts of maxillary and mandibular arches of 300 children, 147 boys and 153 girls within the age group of 12-15 years, with permanent dentitions were fabricated. The mesiodistal crown dimensions of teeth were measured with a dial caliper. Tanaka-Johnston method of mixed dentition arch analysis was performed for the study population, and statistical analysis was done. STATISTICAL ANALYSIS USED: Descriptive statistics including the mean, standard deviation, range, and standard error were calculated and tabulated. RESULTS: Tanaka-Johnston's equation when applied to the data available for Mumbai school children, it was observed that it slightly overestimates the tooth size. CONCLUSIONS: (1) There was a positive correlation between the width of mandibular incisors and mandibular and maxillary canines and premolars. (2) The Tanaka-Johnston prediction method was not accurate for a sample of Mumbai school children.

Valoración de la ecuación de Tanaka-Johnston en estudiantes cubanos con oclusión normal / Assessment of Tanaka-Johnston equation in Cuban students presenting normal occlusion

El análisis de Tanaka-Johnston, mundialmente empleado para la predicción del espacio de caninos y premolares no brotados, ha sido muy cuestionado por la variabilidad en el tamaño dentario entre las diferentes poblaciones, y por haber sido realizado en un grupo étnico no aplicable a todos. Se realizó un estudio descriptivo transversal, con el objetivo de determinar el ancho mesiodistal de incisivos, caninos y premolares mandibulares, así como de caninos y premolares maxilares, y comparar la suma real de estos dientes con los estimados por Tanaka-Johnston, según el sexo y la arcada. El universo de esta investigación estuvo constituido por 50 estudiantes de la Facultad de Estomatología de La Habana, 25 del sexo femenino y 25 del sexo masculino, con oclusión normal, sin antecedentes de tratamiento ortodóncico; todos descendientes de cubanos. En los resultados se observó que los anchos mesiodistales de los incisivos, caninos y primeros premolares inferiores y de caninos y segundo premolar izquierdo superiores fueron significativamente mayores en el sexo masculino que en el femenino. La suma real de caninos y premolares superiores e inferiores fue mayor en el sexo masculino que en el femenino. Cuando se comparó la suma real de caninos y premolares, con lo estimado según la ecuación de Tanaka-Johnston, se halló que la esta sobrestimó los valores de caninos y premolares, ya que los resultados fueron significativamente menores(AU)

The Tanaka-Johnston analysis used at worldwide to predict the space of non-erupted canines and premolars has been questioned due to the variability in the teeth size among different populations and also to be carried out in non-applicable whole ethnic group. A cross-sectional and descriptive study was conducted to determine the mesiodistal width of mandibular incisives, canines and premolars, as well as of danines and premolar-maxillary and to compare the real sum of these theeth with the estimates by Tanaka-Johnston, according to sex and the arcade. Universe of this research included 50 students of Stomatology Faculty of havana (25 males and 25 females) presenting with normal occlusion, without a history of Orthodontics treatment all of them descendants of Cubans. In results it was noted that the mesiodistal widths of incisives, canines and first lower premolars and of canines and second left premolars upper are greater in male sex than in the female one. The real sum of upper and lower canines and premolars was greter in male sex than in the female one. Comparing the real sum of canines and premolars with that estimated according Tanaka-Johnston, it was noted that it overestimated the values of canines and premolar since the results were significantly lower(AU)

Valoración de la ecuación de Tanaka-Johnston en estudiantes cubanos con oclusión normal / Assessment of Tanaka-Johnston equation in Cuban students presenting normal occlusion

El análisis de Tanaka-Johnston, mundialmente empleado para la predicción del espacio de caninos y premolares no brotados, ha sido muy cuestionado por la variabilidad en el tamaño dentario entre las diferentes poblaciones, y por haber sido realizado en un grupo étnico no aplicable a todos. Se realizó un estudio descriptivo transversal, con el objetivo de determinar el ancho mesiodistal de incisivos, caninos y premolares mandibulares, así como de caninos y premolares maxilares, y comparar la suma real de estos dientes con los estimados por Tanaka-Johnston, según el sexo y la arcada. El universo de esta investigación estuvo constituido por 50 estudiantes de la Facultad de Estomatología de La Habana, 25 del sexo femenino y 25 del sexo masculino, con oclusión normal, sin antecedentes de tratamiento ortodóncico; todos descendientes de cubanos. En los resultados se observó que los anchos mesiodistales de los incisivos, caninos y primeros premolares inferiores y de caninos y segundo premolar izquierdo superiores fueron significativamente mayores en el sexo masculino que en el femenino. La suma real de caninos y premolares superiores e inferiores fue mayor en el sexo masculino que en el femenino. Cuando se comparó la suma real de caninos y premolares, con lo estimado según la ecuación de Tanaka-Johnston, se halló que la esta sobrestimó los valores de caninos y premolares, ya que los resultados fueron significativamente menores(AU)

The Tanaka-Johnston analysis used at worldwide to predict the space of non-erupted canines and premolars has been questioned due to the variability in the teeth size among different populations and also to be carried out in non-applicable whole ethnic group. A cross-sectional and descriptive study was conducted to determine the mesiodistal width of mandibular incisives, canines and premolars, as well as of danines and premolar-maxillary and to compare the real sum of these theeth with the estimates by Tanaka-Johnston, according to sex and the arcade. Universe of this research included 50 students of Stomatology Faculty of havana (25 males and 25 females) presenting with normal occlusion, without a history of Orthodontics treatment all of them descendants of Cubans. In results it was noted that the mesiodistal widths of incisives, canines and first lower premolars and of canines and second left premolars upper are greater in male sex than in the female one. The real sum of upper and lower canines and premolars was greter in male sex than in the female one. Comparing the real sum of canines and premolars with that estimated according Tanaka-Johnston, it was noted that it overestimated the values of canines and premolar since the results were significantly lower(AU)

Validación de la ecuación de Tanaka-Johnston en una población de escolares yemenita / Validation of Tanaka-Johnston equation in Yemeni schoolboys

El anàlisis del espacio requiere una comparación entre el espacio disponible y el espacio necesario para la alineación de los dientes. El ampliamente usado anßlisis del espacio de Tanaka-Johnston es cuestionado cuando es aplicado a diferentes poblaciones. Por tanto el propósito de este estudio fue determinar el ancho mesiodistal de incisivos, caninos y premolares mandibulares y caninos y premolares maxilares, para validar el anàlisis de Tanaka-Johnston según el sexo en 100 estudiantes yemenitas comprendidos entre las edades de 12 a 16 años. Se encontró diferencias estadísticamente significativas en el ancho mesiodistal de caninos y premolares según el sexo, excepto para el segundo premolar maxilar. La ecuación de Tanaka-Johnston sobreestima el ancho mesiodistal de los segmentos bucales en esta población(AU)

In space-analysis it is necessary a comparison between the available space and the necessary space in teeth alignement. The well-used Tanaka-Jhonston space analysis is questioned when it is applied in different populations; thus, the aim of present study was to determine the mesiodistal width of mandibular incisives, canines and premolar and of maxillary canines and premolar to validate the Tanaka-Johnston analysis according to sex in 100 Yemeni students aged from 12 to 16. There were statistically significant differences in mesiodistal width of canines and premolars according sex, except for the second maxillary premolar. The Tanaka-Johnston equation overrates the mesiodistal width of oral segments in this population.(AU)

Validación de la ecuación de Tanaka-Johnston en una población de escolares yemenita / Validation of Tanaka-Johnston equation in Yemeni schoolboys

El anàlisis del espacio requiere una comparación entre el espacio disponible y el espacio necesario para la alineación de los dientes. El ampliamente usado análisis del espacio de Tanaka-Johnston es cuestionado cuando es aplicado a diferentes poblaciones. Por tanto el propósito de este estudio fue determinar el ancho mesiodistal de incisivos, caninos y premolares mandibulares y caninos y premolares maxilares, para validar el anàlisis de Tanaka-Johnston según el sexo en 100 estudiantes yemenitas comprendidos entre las edades de 12 a 16 años. Se encontró diferencias estadísticamente significativas en el ancho mesiodistal de caninos y premolares según el sexo, excepto para el segundo premolar maxilar. La ecuación de Tanaka-Johnston sobreestima el ancho mesiodistal de los segmentos bucales en esta población(AU)

In space-analysis it is necessary a comparison between the available space and the necessary space in teeth alignement. The well-used Tanaka-Jhonston space analysis is questioned when it is applied in different populations; thus, the aim of present study was to determine the mesiodistal width of mandibular incisives, canines and premolar and of maxillary canines and premolar to validate the Tanaka-Johnston analysis according to sex in 100 Yemeni students aged from 12 to 16. There were statistically significant differences in mesiodistal width of canines and premolars according sex, except for the second maxillary premolar. The Tanaka-Johnston equation overrates the mesiodistal width of oral segments in this population(AU)