Prediction of space available for unerupted permanent canine and premolars in a Nepalese population

Abstract

The newly developed regression equations are more accurate for prediction of width of unerupted permanent teeth in a Nepalese population. Further studies are required based on larger sample size, to confirm the applicability of the new regression equations proposed.

Regression Equations and Probability Tables for Mixed Dentition Analysis in a Nigerian Population

“…The combined gender mean values obtained for the mandibular incisors, mandibular and maxillary canines and premolars were similar to reported findings among the Black Americans, Thai, Senegalese and Asian-Americans populations [15,17,25,26]. Sex-specific values revealed higher values among Nigerian subjects compared to Nepalese populations [21] and the teeth sizes are also comparable to the odontometric data reported for Black South Africans [14] who however have slightly larger teeth sizes among the males. This observed variation in tooth sizes in different racial groups further buttresses the need for development of prediction aids for each racial group.…”

“…The correlation coefficients obtained in this study is comparable to high correlation coefficients in ranges of 0.6 and above reported among American White children [5] Black Americans [15] Thai [17] and Senegalese populations [25] with predominance of higher values in males as also reported in other studies [16,19,25]. However, lower values for correlation coefficients were reported in males among the Thai [17] and Nepalese [21] populations possibly due to gender variability in these populations. The coefficient of determination r 2 of the range of 36% to 44% was observed among the sexes revealing the total variance in canine-premolar widths that could be determined form the knowledge of the combined widths of mandibular incisors.…”

“…There were no statistically significant difference between actual mesiodistal width of canines and premolars in Nigerian sample and the predicted width from the Moyers charts only at the recommended 75th percentile in the maxillary arch for both sexes combined and also in the mandibular arch for male at 85% percentile confidence levels (P>0.05) while there were significant differences at the remaining percentiles. Similar inaccurate predictions with a possibility of overestimation or underestimation of the actual width of the canine and premolars with the Tanaka and Johnston's equations and Moyer's probability chart have also been reported in Black South African [14], Indian [16], Saudi Arab [18], Iranian [20], Nepalese [21], Senegalese [25], Jordanian [28] and Turkish populations [29]. It thus reflects the limitations of these methods when applied to a sample of population other than European descent because of variability in tooth widths.…”

“…However, the validity and accuracy of these data have been questioned when applied to subjects from different ethnic and racial groups since various studies have shown that tooth sizes vary significantly between different population and racial groups [12,13]. It is therefore important to determine prediction aids for each racial group since each population has its own tooth characteristics and evaluate possible gender differences and secular trend [14][15][16][17][18][19][20][21]. Variation in tooth sizes has also been described in Nigerian subjects when compared to British and African American subjects respectively [22,23].…”

Unerupted Canine and Premolars Width Estimation Based on Bayesian Approach: A Comparative Study

“…(13)(14)(15)(16)(17). On the other hand, applicability of Moyers and Tanaka method has been tested by some researchers and they found that these methods do not truly predict unerupted canine and premolars space in their sample (17).…”