title: Class, type and position of 9148 surgically removed third molars in 3206 patients: a retrospective study.
abstract: OBJECTIVE
  To investigate the class, type, position, diagnosis and most common procedures used in the surgical removal of third molars, and evaluate the sex and age distribution in a representative sample of Mexican patients.
  
  
  METHODS
  A retrospective descriptive study was made covering the period 1993-2008 in relation to 9148 extracted third molars in 3206 patients treated in the Dental School of Salle Bajío University, A.C. (Mexico). Patients of either sex and aged 11-59 years, with at least one third molar programmed for surgical removal, were included in the study. A descriptive statistical study was made.
  
  
  RESULTS
  The mean patient age was 27.6 ± 10.6 years. There were 2093 females (65.3%) and 1111 males (34.6%). In relation to the 4025 upper molars, extraction was decided for prophylactic reasons in 3827 cases (95.08%). Type A presentations were recorded in 1929 cases (47.9%), with a vertical position in 1931 teeth (48%). In relation to the 5123 lower third molars, extraction was likewise most often indicated for prophylactic reasons (4424 cases, 86.36%). A total of 2353 teeth corresponded to type A (45.9%), 2545 were class I cases (49.7%), and a mesioangular position was observed in 1850 cases (36.1%).
  
  
  CONCLUSIONS
  The present study shows that in Mexican patients, upper third molars most often correspond to type A and class I, with a vertical position, while lower third molars predominantly correspond to type A and class I, with a mesioangular position. This information can help dental surgeons take better decisions before and after surgery, to the benefit of their patients.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Dental School, Salle Bajío University, A.C. León, Guanajuato, Mexico. benjasmt@prodigy.net.mx
authors.forename: Benjamín
authors.initials: B
authors.lastname: Morales-Trejo
authors.forename: Miriam-Lucía
authors.initials: ML
authors.lastname: Rocha-Navarro
authors.forename: Anselmo-Luciano
authors.initials: AL
authors.lastname: Acosta-Veloz
authors.forename: Angélica
authors.initials: A
authors.lastname: Juárez-Hernández
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008964:Molar, Third / Q000033:anatomy & histology / Q000601:surgery*; D012189:Retrospective Studies; D014081:Tooth Extraction; D055815:Young Adult