Jangbu Sherpa
Kanti Children’s Hospital, Nepal
Title: Applicability of Tanaka-Johnston and Moyers mixed dentition analyses in Northeast Han Chinese
Biography
Biography: Jangbu Sherpa
Abstract
Objectives: To assess the applicability of Tanaka and Johnston equations and Moyers prediction method in Han ethnic group of
Northeast China and to develop the prediction equations for the same population.
Design: This work is a cross-sectional study.
Setting: Department of Orthodontics, School of Stomatology, Jiamusi University, Heilongjiang, China.
Participants: A total of 130 subjects (65 male and 65 female) aged 16-21 years from Han ethnic group of Northeast China were
recruited from dental students of Jiamusi University and patients seeking orthodontic treatment at Department of Orthodontics,
School of Stomatology, Jiamusi University. Ethnicity was verified to 2 previous generations by questionnaire.
Methods: Study models were fabricated from alginate impression and mesio-distal width of teeth were measured with Digital Vernier
caliper. The predicted values obtained from Tanaka-Johnston and Moyers methods in both arches were compared with the actual
measured widths. Based on regression analysis, prediction equations were developed.
Results: Tanaka and Johnston equations were not precise, except for the upper arch in males. However, the Moyers 85th percentile in
upper arch and 75th percentile in lower arch predicted sum precisely in males. For females, the Moyers 75th percentile predicted the
sum precisely for upper arch, but none of the Moyers percentiles predicted in lower arch.
Conclusions: Both Tanaka and Johnston equations and Moyers’ method may not be applied universally without question. Thus it may
be safer to develop regression equation for specific population. Validating studies must be conducted to confirm the precision of the
newly developed regression equations.