Forty-year review of extraction frequencies at a university orthodontic clinic.

In a review of consecutive charts at 5-year intervals from the orthodontic clinic at the University of North Carolina, the number of patients with extraction of all four first premolars increased from 10% in 1953 to 50% in 1963, remained at 35% to 45% until the early 1980s, then declined sharply to the 1950s level by 1993. Extraction for camouflage of Class II malocclusion (maxillary first premolars alone or maxillary first-mandibular second premolars) reached 16% in 1968, then declined, but not as dramatically, and presently is as frequent as the extraction of four first premolars. The rate of extraction of other teeth, done for a variety of individual reasons, has remained almost constant at about 15% for the past 40 years. Thus the total extraction percentage was 30% in 1953, peaked at 76% in 1968, and declined again to 28% in 1993, with almost all the change in the percentage of four first premolar extractions. The increase in first premolar extractions occurred primarily in a search for greater long-term stability; the recent decline seems due to a number of factors. Greater concern about the impact of extraction on facial esthetics, data to suggest that extraction does not guarantee stability, concern about temporomandibular dysfunction, and changes in technique all seem to have played a role. With appropriate orthodontic mechanics, many patients with Class I crowding can be treated satisfactorily with or without premolar extraction.