Comparison between Tanaka/Johnston and Boston University prediction approaches in a group of Iraqi pupils

Abstract

The purpose of this study was to compare two mixed dentition prediction methods that do not require the use of periapical radiographs of the unerupted permanent lower teeth. The two compared methods were the Tanaka/Johnston (T/J) and the Boston University (BU) prediction approaches. Study casts of 52 children (20 males and 32 females) were used; those children were selected from primary and secondary schools located in different areas of Mosul City. All subjects have normal Class I molar relationship. The finding indicated that on the average the T/J approach overestimated the tooth size of the unerupted teeth (mean + SD = 1.02 + 1.07 mm). On the other hand, the BU approach underestimated the tooth size of the unerupted teeth (mean + SD =-0.2 + 1.07 mm). The findings further indicated that there were statistically significant correlation between the predicted and actual tooth size. The error involved in the use of the prediction equations was expressed as the standard error of the estimate (SEE). The present findings indicated that the SEE for T/J prediction ranged between 0.52-0.63 mm and the corresponding values for BU equation ranged between 0.45-0.68 mm. Depending on the stage of dental development; i.e., which deciduous and permanent teeth are present, the T/J approach can be used when the only permanent four mandibular incisors have completely erupted, whereas the BU approach can be used when all the deciduous (canines and first molars) are still present.

Estimation of the Crown Widths of Un-erupted Canine and Premolars by Using Vistibulo-oral Crown Dimensions of Per-manent Teeth

“…Sums of MDD of C, P1 and P2 in both jaws predicted by this method were more precise in males this agreed with Legovic et al (16) (Correlation coefficient for males 0.84 in the maxilla and 0.85 in the mandible ,and for female 0.79 in the maxilla and 0.78 in the mandible) and with Staley et al (24) which made similar observations. According to Staley et al (24) the prediction of the width of the crowns of teeth is more reliable on the left than on the right side of the jaw, while in our study the side is not important because there is no significant difference in the MDD of teeth between right and left sides of the jaws for both males and females .This agreed with Awni (13) and legovic et al (16) The VOD of the M1 crown is used as a predictor in this study. According to Potter (25) the VOD of the teeth in the maxilla more strongly controlled than the genetic system of MDD.…”

“…(12) The widely used Tanaka and Johnston space analysis is a simple method to predict the sizes of unerupted canine and premolars in mixed dentition but it over estimates the sizes of these teeth. (13) Other method are based on measurements taken directly from radiograph. (14) Some methods based on tooth size averages use established tables of average tooth sizes.…”

Primary Dentition Analysis: Exploring a Hidden Approach

“… 4 In another study on Iraqi population, there was 0.17 correlation of T/J and 0.22 correlation of BU approach with the original teeth dimensions. 5 In the present study, the children studied were still in mixed dentition and the study design was cross-sectional; hence, we could not compare the predicted values with the original ones. This is the major limitation of the present study, though we are planning to prospectively follow the children to get the original dimensions as a further study.…”

“…Moreover, T/J approach was the one that was used for comparison in the previous studies on BU method. 4 5 …”

“…Subsequently, two studies were carried out on this approach, one on Iowa population and the other on Iraqi population. 4 5 Hence, the present study was conducted to test the validity of BU approach by comparing it with T/J approach in the contemporary population.…”