Applegate’s Rules for Applying the Kennedy Classification
Rule 1: Classification should follow rather than precede extraction.
Rule 2: If the 3rd molar is missing and not to be replaced, it is not considered in the classification.
Rule 3: If the 3rd molar is present and to be used as an abutment, it is considered in the classification.
Rule 4: If the second molar is missing and not be replaced, it is not considered in the classification.
Rule 5: The most posterior edentulous area determines the classification.
Rule 6: Edentulous areas other than those determining classification are called modification spaces.
Rule 7: The extent of the modification is not considered, only the number.
Rule 8: There is no modification space in Class IV.