title: [Association of mandibular angle size with cortical thickness and residual ridge height of the edentulous mandible].
abstract: OBJECTIVE
  To evaluate the mandible angle and to investigate the relationship of angle size to gender, age-group, cortical thickness at the mandibular angle (CTMA), height of mandibular residual body, and edentulous period in the elderly edentulous subjects.
  
  
  METHODS
  A total of 356 panoramic radiographs of three groups of subjects were evaluated: the young dentate group, 131 subjects (mean age: 27); the older dentate group, 97 (mean age: 64); and the elderly edentulous group, 128 (ages 76, 81, or 86). Mandibular angle size, CTMA, and height of mandibular residual body were measured from panoramic radiographs. A structured questionnaire was used to determine the history of edentulousness.
  
  
  RESULTS
  Difference in angle size was found between dentate men and women (P < 0.05, P < 0.001), but not between the elderly edentulous men and elderly women. The elderly edentulous subjects had larger mandibular angles than did older dentate subjects (P < 0.001). The angle size was negatively related to CTMA only among 76-year-old edentulous women (P < 0.01) and negatively associated with average height of the mandibular residual body in the edentulous men and women (P < 0.01). No association existed between angle size and duration of edentulousness.
  
  
  CONCLUSIONS
  Elderly edentulous subjects have large mandibular angles and the angle size is correlated with low-height of the mandibular residual body, which suggests that masticatory function of natural dentition and complete denture may influence change of the mandibular angle. The significant relationship of mandibular angle size to CTMA probably indicates the effect of systemic factors on change in the mandibular angle.
authors.affiliation: Department of Prosthodontics, Peking University School of Stomatology, Beijing 100081, China. qfxie@public.bta.net.cn
authors.forename: Qiu-Fei
authors.initials: QF
authors.lastname: Xie
authors.forename: Anja
authors.initials: A
authors.lastname: Ainamo
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000539:Alveolar Process / Q000000981:diagnostic imaging / Q000473:pathology*; D002508:Cephalometry; D005260:Female; D006801:Humans; D007575:Jaw, Edentulous / Q000000981:diagnostic imaging*; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000473:pathology*; D008875:Middle Aged; D011859:Radiography