Prediction of agenesis of the maxillary second premolar based on the developmental stages of the maxillary canine, first premolar, and second molar

Abstract Objective This study aimed to suggest criteria for the early diagnosis of agenesis of the maxillary second premolars (U5) based on the developmental stages of the maxillary canines (U3), first premolars (U4), and second molars (U7). Design Overall, 303 control patients and 72 patients with agenesis who met the inclusion criteria were analyzed among 5136 patients aged 5–11 years for whom panoramic radiographs were obtained at Seoul National University Dental Hospital from June 2008 to December 2009. All developmental stages of U3, U4, U5, and U7 in both groups were evaluated and categorized into the stages proposed by Demirjian et al. To confirm the delayed dental development in the agenesis group, the Wilcoxon rank sum test was used. For verifying the tooth with the most similar developmental pattern to U5, the Kendall tau Rank Correlation and Bootstrap methods were used. Moreover, survival analysis and leave-one-out-cross-validation were performed to identify the earliest developmental stages of U3, U4, and U7 at which agenesis of U5 can be confirmed. Results The developmental stage of U4 in the agenesis group was significantly delayed compared with that in the control group at ages 5–10. All of the stages of U3, U4, and U7 showed high correlation coefficients with U5. Conclusion U5 agenesis can be confirmed with high prediction accuracy when at least two of the three conditions are satisfied: U3, U4, and U7 in Demirjian stages E, D, and C, respectively.