Background: Moyer’s probability tables have been widely used to determine the mesiodistal dimensions of unerupted canines and premolars for mixed dentition space analysis. Secular, racial, and sexual dimorphism have been reported in the literature and the applicability of Moyer’s analysis has been doubted in many other populations.
Objectives: The present study was conducted to determine the applicability of Moyer’s probability tables and develop a more accurate prediction method in a contemporary Western Australian adolescent population.
Methods: A retrospective study, including 500 participants (323 females, 177 males) between 13-18 years old attending the orthodontic private practice, was conducted. Mesiodistal dimensions of selected participants were obtained from pre-orthodontic treatment digital dental records using Invisalign® technology (Invisalign®, Align Technology, Santa Clara, CA, USA). Data were analysed using SPSS. New regression equations were derived based on the sum of permanent mandibular incisors, and probability tables were proposed for more accurate prediction.
Results: Significant differences were found between the measured sum of permanent canine-premolar segments and those predicted with the Moyer’s probability table, at all percentile levels, except the 50th percentile, where no significant difference was observed.
Conclusion: Moyer’s probability table can be applied at the 50th percentile for estimation of sum of mesiodistal dimensions of canine-premolars segments. Newly developed regression equations and tables could be considered to provide more accurate mixed dentition space analysis.