“…Based on NTDC-related ED visit publications,1,5,6,14 the following ICD-9-CM codes were used: 521.0–521.9 (diseases of dental hard tissues of teeth), 522.0–522.9 (diseases of pulp and periapical tissues), 523.0–523.9 (gingival and periodontal diseases), 525.3 (retained dental root), and 525.9 (unspecified disorder of the teeth and supporting structures) 1,5,6,14. Additional covariates included information on age, sex, insurance, patient-stated reason for visit, calendar year, region, location in a Metropolitan Statistical Area, and hospital ownership.…”