Results
In the univariate analysis factors race and side proved to be insignificant by the Wald test at 5% significance level. Hence the eruption sequence does not significantly differ among the Races and remains unchanged between left and right side in the mouth. Then a multivariate CoxPH model was fitted using variables District, SS, gender, jaw and type which were the significant variables in the univariate analysis. These five variables continued to be significant in the fitted multivariable model as indicated by the p-values in Table 01 and hence no variables are dropped.
The two factors Race and side were reintroduced the model separately and no factor became insignificant due to this. Hence Race and side can be concluded as factors not …show more content…
That is for a given pair of observations the model is capable of indicating with 85.6% accuracy, a shorter period of time to erupt for the observation with the greater risk of tooth eruption. The log-rank test yielded a p-value of 1 for the comparison of the two survival curves in Figure 1.This suggest similar behaviour between the observed probabilities of tooth eruption and the predicted Survival probabilities from the CoxPH model. Hence, we conclude that the multivariate survival model fitted above has a high predictive power.
The hazard ratio of M1 relative to I1 is 1.89 whereas the hazard ratio of other teeth types relative to I1 are less than 1. This indicates that M1 is the first to erupt and that other types of teeth emerge after I1. By similar argument comparing the hazard ratios of each (k, j) pairs given by Table 02 we derive the general eruption sequence provided in Table 03. The first teeth to emerge is M1, then the incisors followed by PM1, C, PM2 and the last tooth to emerge in both genders is …show more content…
The hazard ratio for boys is 0.76 indicating a 24% lower potential to teeth eruption than girls. Hence tooth eruption happens sooner in girls than boys. By similar interpretation of hazard rates teeth euption happens ealier in girls relative to boys and eruption in lower jaw precedes that of upper jaw. The hazard ratio for teeth in lower jaw is 1.24 indicating a 24% higher hazard of teeth eruption relative to upper jaw. This suggest that teeth eruption in lower jaw precedes that in upper jaw.
The highest hazard ratio of 1.32054 is that of Rathnapura relative to Colombo .Districts Kurunegala & Galle also have hazard ratios greater than 1.whereas the hazard ratios for other Districts relative to Colombo are less than 1. The results clearly indicate the presence of a geographical variation in tooth eruption sequences. Accordingly the tooth eruption happens in children of Southern and North Central provinces much earlier than in Western Province where the capital of the country is
In the univariate analysis factors race and side proved to be insignificant by the Wald test at 5% significance level. Hence the eruption sequence does not significantly differ among the Races and remains unchanged between left and right side in the mouth. Then a multivariate CoxPH model was fitted using variables District, SS, gender, jaw and type which were the significant variables in the univariate analysis. These five variables continued to be significant in the fitted multivariable model as indicated by the p-values in Table 01 and hence no variables are dropped.
The two factors Race and side were reintroduced the model separately and no factor became insignificant due to this. Hence Race and side can be concluded as factors not …show more content…
That is for a given pair of observations the model is capable of indicating with 85.6% accuracy, a shorter period of time to erupt for the observation with the greater risk of tooth eruption. The log-rank test yielded a p-value of 1 for the comparison of the two survival curves in Figure 1.This suggest similar behaviour between the observed probabilities of tooth eruption and the predicted Survival probabilities from the CoxPH model. Hence, we conclude that the multivariate survival model fitted above has a high predictive power.
The hazard ratio of M1 relative to I1 is 1.89 whereas the hazard ratio of other teeth types relative to I1 are less than 1. This indicates that M1 is the first to erupt and that other types of teeth emerge after I1. By similar argument comparing the hazard ratios of each (k, j) pairs given by Table 02 we derive the general eruption sequence provided in Table 03. The first teeth to emerge is M1, then the incisors followed by PM1, C, PM2 and the last tooth to emerge in both genders is …show more content…
The hazard ratio for boys is 0.76 indicating a 24% lower potential to teeth eruption than girls. Hence tooth eruption happens sooner in girls than boys. By similar interpretation of hazard rates teeth euption happens ealier in girls relative to boys and eruption in lower jaw precedes that of upper jaw. The hazard ratio for teeth in lower jaw is 1.24 indicating a 24% higher hazard of teeth eruption relative to upper jaw. This suggest that teeth eruption in lower jaw precedes that in upper jaw.
The highest hazard ratio of 1.32054 is that of Rathnapura relative to Colombo .Districts Kurunegala & Galle also have hazard ratios greater than 1.whereas the hazard ratios for other Districts relative to Colombo are less than 1. The results clearly indicate the presence of a geographical variation in tooth eruption sequences. Accordingly the tooth eruption happens in children of Southern and North Central provinces much earlier than in Western Province where the capital of the country is