According to Finn, the best method of brushing for mixed dentition:

The four basic methods of tooth brushing are: Horizontal reciprocating (Scrub method) Vertical sweeping (Roll and physiologic methods) Circular (Fones method) Vibratory (Charters, Bass and Stillman methods) Key Concept: Brushing Technique used commonly in children  The circular brushing method or Fone’s technique is a natural brushing method to use with young children who want to do their own brushing, but do not have the muscle development for techniques that require more co-ordination.