Class 1: Simple fracture of the crown involving little or no dentin.

Class 2: Extensive fracture of the crown involving considerable dentin but not pulp.

Class 3: Extensive fracture of the crown involving considerable dentin, and exposing the dental pulp.

Class 4: The traumatized tooth which becomes nonvital with or without loss of crown.

Class 5: Teeth lost as a trauma.

Class 6: Fracture of the root with or without loss of crown structure.

Class 7: Displacement of the tooth without fracture of crown or root.

Class 8: Fracture of the crown en masse and its replacement.

Class 9: Traumatic Injury to primary dentition