1. Classification of malocclusion;Angle;Dent. Cosmos,1899
2. Variations in facial relationships: Their significance in treatment and prognosis;Downs;Am. J. Orthod.,1948
3. Studies of dento-facial morphology. 1. A simple instrument for appraising variations;Elsasser;Angle Orthod.,1951
4. Orthodontic treatment priority index;Grainger,1967
5. Malocclusion severity assessment;Salzmann;Am. J. Orthod.,1967