The document discusses various disturbances that can occur during dental development including congenitally missing teeth, malformed teeth, supernumerary teeth, interference with eruption, ectopic eruption, early loss of primary teeth, and traumatic displacement of teeth. These disturbances can result in malocclusion and crowding. Specific examples discussed include hypodontia, peg-shaped lateral incisors, mesiodens supernumerary teeth, ectopic eruption of molars, early loss of primary molars leading to mesial drift of permanent molars, and displacement of teeth due to injury. Treatment may involve orthodontics, extractions, or prosthetics depending on the individual clinical scenario.