 During primary dentition, the tooth buds of permanent teeth develop inferior to the primary teeth, close to the palate or tongue.Mixed dentition stage starts when the first permanent tooth appears in the mouth, usually at five or six years with the first permanent molar, and lasts until the last primary tooth is lost, usually at ten, eleven, or twelve years.There are 32 permanent teeth and those of the maxillae erupt in a different order from permanent mandibular teeth.