title: Reasons why erupted third molars are extracted in a public university in Mexico.
abstract: OBJECTIVE
  The aim of this study was to determine the reasons for which erupted third molars (3M) are extracted in a sample of Mexican patients.
  
  
  METHODS
  A retrospective cross-sectional study was performed on a sample of 83 patients attending exodontia (minor oral surgery) clinics of a public university in Mexico (Autonomous University of Hidalgo State). The outcome variable was the reason for extractions using Kay and Blinkhorn's classification. The independent variables were age, gender, arch and tooth number according to the World Health Organization (WHO). For statistical analysis, we used the Chi-squared test in Stata 9.0.
  
  
  RESULTS
  Eighty-three patients underwent 150 3M extractions. Mean age was 38.67 ± 13.96 years, and 71.1% were female. The four reasons for 3M extraction were prosthetic (44.0%), followed by orthodontic (24.7%), dental caries (20.0%) and periodontal disease (11.3%). Differences were observed in the reasons for 3M extractions across age groups (p < 0.05). No significant differences existed between men and women (p > 0.05), or the WHO tooth number (p > 0.05).
  
  
  CONCLUSIONS
  Women and patients 18 to 34 years of age had erupted 3M extracted more frequently, primarily for prosthetic reasons. The age profile indicated a trend in demand for services that differ from those of overall tooth extractions, but not for the trend across gender.
authors.affiliation: Avenida del Álamo # 204, Fraccionamiento Paseo de los Solares, Colonia Santiago Tlapacoya, CP 42110, Pachuca de Soto, Hidalgo, México. cemedinas@yahoo.com.
authors.forename: C E
authors.initials: CE
authors.lastname: Medina-Solís
authors.affiliation: Academic Area of Dentistry of Health Sciences Institute at Autonomous University of Hidalgo State, Pachuca, Hidalgo, Mexico.
authors.forename: M
authors.initials: M
authors.lastname: Mendoza-Rodríguez
authors.affiliation: Academic Area of Dentistry of Health Sciences Institute at Autonomous University of Hidalgo State, Pachuca, Hidalgo, Mexico.
authors.forename: S
authors.initials: S
authors.lastname: Márquez-Rodríguez
authors.affiliation: Academic Area of Dentistry of Health Sciences Institute at Autonomous University of Hidalgo State, Pachuca, Hidalgo, Mexico.
authors.forename: R
authors.initials: R
authors.lastname: De la Rosa-Santillana
authors.affiliation: Academic Area of Dentistry of Health Sciences Institute at Autonomous University of Hidalgo State, Pachuca, Hidalgo, Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Islas-Zarazua
authors.affiliation: Academic Area of Dentistry of Health Sciences Institute at Autonomous University of Hidalgo State, Pachuca, Hidalgo, Mexico.
authors.forename: J-D J
authors.initials: JD
authors.lastname: Navarrete-Hernández
authors.affiliation: Indiana University/Purdue University at Indianapolis School of Dentistry, Indianapolis, Indianapolis, USA; The Regenstrief Institute, Inc., Indianapolis, Indiana, USA.
authors.forename: G
authors.initials: G
authors.lastname: Maupomé