<prompt> First to classify malocclusion on structural basis?SalzmannKingsleyAngleKatz  <response>: Salzmann in 1950 was the first to classify on occlusion based on the underlying skeletal structures.1. SKELETAL CLASS I2. SKELETAL CLASS II3. SKELETAL CLASS IIIn 1899, Edward Angle classified malocclusion based on the mesial-distal relation of the teeth, dental arches and jaws.Morton Katz 1992 shifted the focus from the molars, canines and incisors to the region of premolars for the purpose of classifying malocclusion.KINGSLEY 1956Based on the nature of the habits, Kingsley 1956 classified habits as:Functional oral habit - E.g. mouth breathing.Muscular habits - Eg. tongue thrusting, cheeklip biting.Combined muscular habits - Eg. thumb and finger sucking.Postural habits.Chin-proppingFace leaning on handAbnormal pillowing.Ref: Textbook of orthodontics Gurkeerat Singh 2nd ed page no 175 