Evaluation of Tanaka and Johnston and Moyers Mixed  Dentition Space Analysis in a Population of Mysore, India

Authors

Suma S1 , Chandrashekar BR2 , Bhagyalakshmi A3 , Raghunath N 4 , Pradeep S 5, Avinash BS 6

Mixed dentition analysis, Moyer’s analysis, Regression equations, Tanaka and Johnston analysis.

Objectives: To evaluate applicability of Tanaka and Johnston (T&J) and Moyer’s mixed dentition prediction

methods and formulate regression equations for predicting mesiodistal widths of unerupted canines and

premolars in Mysore population. Dental casts of 400 Mysore subjects aged 16-23years were used. Mesiodistal

dimensions of mandibular permanent incisors, maxillary and mandibular permanent canines, first and second

premolars were measured using a digital calliper calibrated to 0.01mm. Actual teeth measurements were

then statistically compared with predicted values derived from T&J’s equations and Moyers probability

tables at 75th percentile. T&J prediction equations overestimated mesiodistal widths of permanent canines

and premolars in both arches. Moyers 75th percentile also overestimated actual measurements except for

maxillary arch in female subjects. Percentage of overestimation was more for T&J prediction method than

Moyers. Regression equations and probability tables derived for tooth size prediction for Mysore population

would be more accurate when applied locally.

Suma S1 , Chandrashekar BR2 , Bhagyalakshmi A3 , Raghunath N 4 , Pradeep S 5, Avinash BS 6

Reader, 4Professor, 5Lecturer Orthodontics, JSS Dental College, JSSAHER Mysore, 2Professor, Public Health

Dentistry, JSS Dental College, JSSAHER Mysore, 6 Reader, Periodontics, JSS Dental College, JSSAHER Mysore