title: A histomorphometric and scanning electron microscopy study of human condylar cartilage and bone tissue changes in relation to age.
abstract: OBJECTIVE
  To determine the possibility for adaptive growth in human condyles, quantifying the thickness of fibrocartilage and the constitution of cells with potential activity, the trabecular bone volume, and the structural parameter: marrow space star volume in a larger sample of human autopsy condyles. EXPERIMENTAL SETTING AND DESIGN: A histomorphometric and scanning electron microscopic analysis of cartilage characteristics and bone remodelling activity. The Departments of Orthodontics and Cell Biology at Aarhus University, Denmark. An autopsy sample of condyles from 20 individuals, 18-31 years of age. Correlation analyses between ages and all parameters were conducted.
  
  
  RESULTS
  There was a statistically significant correlation between age and the fibrocartilage thickness (r = -0.48, p < 0.05) and age and the trabecular bone volume (r = -0.52, p < 0.05). There was a statistically significant correlation between age and the hypertrophic chondrocytes (r = -0.50, p < 0.05) and age and the hypertrophic chondrocytes in bone (r = -0.48, p < 0.05). There was no significant correlation between age and the two other zones in the fibrocartilage. No statistical analyses were carried out concerning gender differences, as the sample consisted of very few females. Individual morphological description was performed, and is described in the article. Only slight age-related differences were found concerning the quantitative measurements for the fibrocartilage and the underlying bone tissue.
  
  
  CONCLUSIONS
  Quantitative and qualitative investigations of the turnover activity in the fibrocartilage and the bone tissue, describing activity of hypertrophic chondrocytes and the trabecular bone tissue, indicated condylar growth potential in the age group until 30 years of age. The growth activity seemed to decline with age.
authors.affiliation: Department of Orthodontics, Copenhagen Municipal Dental Health Service, Denmark. hpaulsen@get2net.dk
authors.forename: H U
authors.initials: HU
authors.lastname: Paulsen
authors.forename: J S
authors.initials: JS
authors.lastname: Thomsen
authors.forename: H P
authors.initials: HP
authors.lastname: Hougen
authors.forename: L
authors.initials: L
authors.lastname: Mosekilde
mesh_terms: D000222:Adaptation, Physiological; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000375:Aging / Q000502:physiology*; D016723:Bone Remodeling; D002358:Cartilage, Articular / Q000648:ultrastructure*; D020219:Chondrogenesis / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008297:Male; D008335:Mandibular Condyle / Q000254:growth & development / Q000648:ultrastructure*; D008445:Maxillofacial Development; D008855:Microscopy, Electron, Scanning