On 22 May at 15:00, in a public session of the Doctoral Committee of Medicine, Rīga Stradiņš University, which will take place at the Hippocrates Lecture Theatre (16 Dzirciema Street), Māris Gržibovskis will defend his doctoral thesis “Quantitative Assessment of Signalling Molecules in Human Interradicular Septum Tissues of Different Age Groups”.
Orthodontic treatment is a combined and often also an interdisciplinary process, this can be particularly observed when treating already mature patients. It consists of orthodontic treatment with fixed braces system and, at times, periodontological, prosthetical and surgical treatment. Orthodontic treatment is usually started at the age of 12-14, when a permanent occlusion is established. Both boys and girls at this age may have a different occlusion development phase, which is linked to the reaching of puberty.
There is no age limit for orthodontic treatment unless there are conditions that may influence the outcome of the treatment, however, with age regularity exists regarding the duration of the treatment which may have a connection with the factors involved in the remodelling process, their amount and activity.
Aim of the study was to identify the expression of degeneration, growth, mineralization and inflammation signalling molecules in the interradicular septum tissues in order to substantiate the tissue remodelling possibilities during the orthodontic treatment process depending on age.
The study group included 45 patients who had been diagnosed dentoalveolar anomalies and who needed orthodontic treatment. Patients were divided into three groups according to age, 15 patients per group.
By using immunohistochemistry method the author detected and analysed the expression of growth factors and their receptors (TGFβ, RANKL, OPG, FGFR1, bFGF), citokin (IL6), bone extracellular matrix proteins (OC) and extracellular matrix degradation enzymes (MMP8, MMP9), as well as determined the relative frequency of apoptosis in alveolar bone and periodontal tissues by using a special method.
Statistically significant decrease of apoptotic cells in the interradicular septum of human bone tissues with age points to the decrease of bone remodelling. Mutual correlation of OPG, RANKL, TGFβ and apoptosis indicates the overall reduction in the interradicular septum cell activity, osteoclastic activity, bone growth and remodelling potential from the ontogenetic aspect.