Mixed Dentition Analysis and Prediction Methods

Mixed dentition analysis is the clinical assessment used to estimate the combined mesiodistal widths of unerupted permanent canines and premolars during the transitional phase when primary and permanent teeth coexist. Traditional approaches rely on probability tables and simple linear equations that correlate measurements of erupted incisors with the size of later-erupting teeth. The two most established methods—the Moyers probability tables and the Tanaka-Johnston equations—provide percentile-based and regression-based predictions respectively, allowing practitioners to gauge space requirements for alignment or extraction decisions. Recognition of ethnic and sexual variation has driven the creation of bespoke regression models that incorporate additional predictor teeth (for example, first molars) and leverage digital measurement techniques, including three-dimensional scanning and cone-beam computed tomography. Contemporary research emphasises multivariate frameworks to refine accuracy, reduce estimation error and ensure applicability across global populations. Precise prediction underpins interceptive orthodontic planning, guiding decisions such as space maintenance, arch expansion or selective extraction, and ultimately contributes to more efficient and less invasive treatment protocols.

Research from Nature Portfolio

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Research from all publishers

Several recent investigations have examined the performance of established mixed dentition prediction methods in diverse populations. In a northern Iranian cohort, researchers compared Tanaka-Johnston equations and various percentile levels of the Moyers tables against actual cast measurements, finding that Tanaka-Johnston consistently overestimated space requirements while a 65% confidence interval from Moyers’ tables for the mandible yielded the closest agreement. This led to new regression formulas based on combined measures of first molars and incisors. In Pakistan, clinicians evaluated the suitability of Moyers’ mixed dentition tables and established population-specific probability charts; by integrating mandibular incisors with maxillary first molar dimensions, they markedly improved prediction accuracy, particularly in male subjects. Among Kenyan adolescents, inclusion of lower first permanent molars alongside incisors in regression models produced higher correlation coefficients than the Tanaka-Johnston method, prompting a novel equation tailored to that population’s dental morphology. Collectively, these studies highlight the necessity of calibrating predictive tools to local dental characteristics and incorporating supplementary predictors to enhance clinical precision worldwide.

Mixed Dentition Analysis and Prediction Methods publication trend

The graph below shows the total number of articles in mixed dentition analysis and prediction methods across all publications each year (not limited to Nature Index journals).

Technical terms

Mixed dentition analysis: Assessment of available space and prediction of unerupted permanent tooth sizes when both primary and permanent teeth are present.

Mesiodistal crown width: Maximum horizontal measurement of a tooth from its mesial (front) contact point to its distal (rear) contact point.

Moyers probability tables: Population-based percentile charts that estimate the width of unerupted canines and premolars from the sum of lower incisor widths.

Tanaka-Johnston method: Simple linear equations that predict the combined width of unerupted canines and premolars using mandibular incisor measurements.

Regression equation: Statistical model relating one or more predictor tooth measurements to the predicted size of unerupted teeth.

References

1. A computed tomographic, mixed dentition, space analysis comparison. Australian Orthodontic Journal (2016).
2. Comparison of measured and predicted mesiodistal tooth-widths of 13–17 years old Kenyans: a descriptive cross-sectional study to develop a new prediction equation for use in the mixed dentition in a Kenyan population. BMC Oral Health (2022).
3. Application of Moyer’s mixed dentition analysis and establishing probability tables in a sample of Pakistani population. Pakistan Journal of Medical Sciences (2023).