title: Radiographical evaluation of bone quality after extraction of mandibular impacted and semi-impacted third molars.
abstract: OBJECTIVE
  The association between bone quality and fracture risk in the mandibular angle with the presence of impacted/semi-impacted third molars and after their extraction is controversial. This study aimed to assess mandibular bone quality in digital radiographies of patients after extraction of impacted/semi-impacted lower third molars.
  
  
  METHODS
  A total of 130 sets of digital panoramic radiographies were selected and divided into the following three groups: Group 1 with 50 panoramic radiographies of patients with impacted/semi-impacted lower third molars, Group 2 with 30 panoramic radiographies of patients with lower third molar agenesis, and Group 3 with 50 panoramic radiographies of patients after extraction of impacted/semi-impacted lower third molars. The mandibular angular cortex was the anatomical structure used as parameter for bone quality assessment. ANOVA and Student's t test were applied for comparison between groups.
  
  
  RESULTS
  Mandibular angular cortical width was significantly lower when the third molar was present in both genders (P<0.05). Agenesis of the third molar in women was associated with lower thickness of the mandibular cortex when compared with patients who had their third molar extracted (P<0.05).
  
  
  CONCLUSIONS
  It can be concluded that the absence of impacted/semi-impacted lower third molars, was associated with a significant increase in cortical width.
authors.affiliation: Department of Oral Diagnosis and Dental Radiology, State University of Campinas, Campinas, São Paulo, Brazil.
authors.forename: M B C
authors.initials: MB
authors.lastname: Alonso
authors.forename: P P
authors.initials: PP
authors.lastname: Costa
authors.forename: J P M
authors.initials: JP
authors.lastname: Issa
authors.forename: S A C
authors.initials: SA
authors.lastname: Monteiro
authors.forename: R
authors.initials: R
authors.lastname: Tiossi
authors.forename: P C A
authors.initials: PC
authors.lastname: Watanabe
mesh_terms: D000293:Adolescent; D000328:Adult; D004198:Disease Susceptibility; D005260:Female; D005598:Fractures, Spontaneous / Q000453:epidemiology; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging* / Q000601:surgery; D008336:Mandibular Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D008337:Mandibular Fractures / Q000453:epidemiology; D008964:Molar, Third / Q000601:surgery*; D010024:Osteoporosis / Q000000981:diagnostic imaging* / Q000209:etiology; D011183:Postoperative Complications / Q000453:epidemiology; D011184:Postoperative Period; D011862:Radiography, Panoramic; D012306:Risk; D014081:Tooth Extraction; D014095:Tooth, Impacted / Q000150:complications / Q000601:surgery*; D055815:Young Adult