STATISTICAL STUDY OF THE PRIMARY CAUSES OF EXTRACTIONS

¹ School of Dentistry, University of Michigan, Ann Arbor, Mich.

An analysis was made of the causes of extraction of 1,424 teeth. In 59% of the patients studied, teeth were extracted as a result of caries. This comprised 48.8% of all extracted teeth. Each patient averaged 3.29 extractions. The caries group ranged in age from 6 to 81 years, the only causal group that appeared in all ages. Males outnumbered female patients, 3 to 2.

Those in the periodontal disease group comprised 13% of all patients, and 40.7% of all extractions. Each patient averaged 10.35 extractions. Numbers of male and female patients were nearly equal.

Impacted (unerupted) teeth constituted the third largest group, 4.4% of all teeth extracted, involving 3 age groups, from 14 to 40 years. Extractions for prosthetic correction made up the fourth group, with 2.8% of all extractions, but with less than 1% of the total patients. Supernumerary teeth accounted for 0.5% of all extractions, traumatic causes for 0.4%, and surgical involvement, 0.3%.

From this data, the most notable fact seems to be the relative importance of caries and periodontal disease. Almost one-half the extractions were due to caries, and about 40% were due to pyorrhea. Yet caries-extractions averaged approximately 3 per patient, and periodontal disease-extractions were approximately 10 per patient. Although extraction statistics such as these are entirely inadequate in determining the incidence of dental disease and disorders, they do indicate the relative importance of the various disorders in terms of oral health.