The effect of ageing, oestrogen and diet hardness on rat mandibular condylar cartilage
Thesis event information
Date and time of the thesis defence
Place of the thesis defence
Leena Palotie auditorium (101A), Aapistie 5 A
Topic of the dissertation
The effect of ageing, oestrogen and diet hardness on rat mandibular condylar cartilage
Doctoral candidate
DDS Riikka Hauru
Faculty and unit
University of Oulu Graduate School, Faculty of Medicine, Research Unit of Population Health
Subject of study
Dentistry
Opponent
Professor Timo Närhi, University of Turku
Custos
Professor Pertti Pirttiniemi, University of Oulu
Ageing, oestrogen deficiency and masticatory loading influence temporomandibular joint cartilage
Ageing is associated with structural and compositional changes in temporomandibular joint cartilage. A doctoral study conducted at the University of Oulu shows that increasing age is linked to alterations in proteoglycan content and collagen network organisation. Oestrogen deficiency appears to intensify these changes, highlighting the role of hormones in the metabolism of temporomandibular joint cartilage in an experimental model. In addition, the quality of masticatory loading is associated with structural characteristics of the cartilage.
The study examined the effects of ageing, oestrogen levels and dietary loading on temporomandibular joint cartilage in a controlled animal model. Histomorphometry, immunohistochemistry, Fourier-transform infrared (FTIR) spectroscopy and polarised light microscopy (PLM) were used to analyse cartilage structure, collagen organisation and proteoglycan distribution.
The results demonstrated that ageing increased collagen fibre disorganisation and altered cartilage composition. Oestrogen deficiency was associated with further structural impairment. The nature of masticatory loading influenced cartilage thickness as well as collagen and proteoglycan expression, with harder loading conditions appearing to support structural integrity compared with reduced mechanical stimulation.
Although experimental, the findings provide new fundamental knowledge about the biological and mechanical regulation of temporomandibular joint cartilage and contribute to understanding mechanisms that may underlie temporomandibular disorders.
The doctoral research was conducted at the Faculty of Medicine, University of Oulu.
The study examined the effects of ageing, oestrogen levels and dietary loading on temporomandibular joint cartilage in a controlled animal model. Histomorphometry, immunohistochemistry, Fourier-transform infrared (FTIR) spectroscopy and polarised light microscopy (PLM) were used to analyse cartilage structure, collagen organisation and proteoglycan distribution.
The results demonstrated that ageing increased collagen fibre disorganisation and altered cartilage composition. Oestrogen deficiency was associated with further structural impairment. The nature of masticatory loading influenced cartilage thickness as well as collagen and proteoglycan expression, with harder loading conditions appearing to support structural integrity compared with reduced mechanical stimulation.
Although experimental, the findings provide new fundamental knowledge about the biological and mechanical regulation of temporomandibular joint cartilage and contribute to understanding mechanisms that may underlie temporomandibular disorders.
The doctoral research was conducted at the Faculty of Medicine, University of Oulu.
Created 13.2.2026 | Updated 13.2.2026