In a mixed dentition analysis using either Moyers or Tanaka-Johnston techniques, which of the following statements is false?

The Tanaka-Johnston analysis is a method used in mixed dentition to estimate the size of unerupted permanent teeth based on the mesiodistal width of the erupted lower incisors. According to this technique, one first measures the mesiodistal widths of the lower four incisors and then takes half of this total. To obtain the predicted width of the maxillary canine and premolars, you then add a specific value: in this case, 10.5 mm is the correct figure to be added in the standard practice.

Therefore, the assertion about adding 10 mm in the Tanaka-Johnston analysis is inaccurate, as the established standard calls for an addition of 10.5 mm, which makes it the false statement among the options provided. This understanding is critical for accurately predicting the size of unerupted teeth, which is essential for planning orthodontic treatment effectively.