The effect of aging on the bone healing properties of blood plasma.

OBJECTIVES: Age-related changes in blood composition have been found to affect overall health. Thus, this study aimed to understand the effect of these changes on bone healing by assessing how plasma derived from young and old rats affect bone healing using a rat model. METHODS: . Blood plasma was collected from 6-month and 24-month old rats. Differences in elemental composition and metabolome were assessed using optical emission spectrometry and liquid mass spectrometry, respectively. Bilateral tibial bone defects were created in eight rats. Young plasma was randomly applied to one defect, while aged plasma was applied to the contralateral one. Rats were euthanized after two weeks, and their tibiae were analyzed using micro-CT and histology. The proteome of bone marrow was analyzed in an additional group of three rats. RESULTS: Bone-defects treated with aged-plasma were significantly bigger in size and presented lower bone volume/tissue volume compared to defects treated with young-plasma. Histomorphometric analysis showed fewer mast cells, macrophages, and lymphocytes in defects treated with old versus young plasma. The proteome analysis showed that young plasma upregulated pathways required for bone healing (e.g. RUNX2, platelet signaling, and crosslinking of collagen fibrils) whereas old plasma upregulated pathways, involved in disease and inflammation (e.g. IL-7, IL-15, IL-20, and GM-CSF signaling). Plasma derived from old rats presented higher concentrations of iron, phosphorous, and nucleotide metabolites as well as lower concentrations of platelets, citric acid cycle, and pentose phosphate pathway metabolites compared to plasma derived from young rats. CONCLUSION: bone defects treated with plasma-derived from young rats showed better healing compared to defects treated with plasma-derived from old rats. The application of young and old plasmas has different effects on the proteome of bone defects.

The prevalence of premature loss of primary teeth and its impact on malocclusion in the Eastern Province of Saudi Arabia.

OBJECTIVES: The present study was designed to determine the prevalence of premature loss of primary teeth and its effect on malocclusion in Eastern Province, Saudi Arabia. MATERIALS AND METHODS: This is an observational, cross-sectional study that included 307 male children aged 9-11 years old. Clinical examinations were performed using a disposable sharp explorer, a UNC periodontal probe and a dental mirror. The samples were examined clinically to detect the following traits: Angle's classification of malocclusion, overjet, overbite, anterior open-bite, lateral open-bite, midline shift and cross-bite. Additionally, a dental caries examination was performed using WHO methods. Questionnaires in Arabic were coded and sent to the students' parents. RESULTS: The mean DMFT was 5.61 (SD = 3.01). The d-component was the highest, with a mean of 4 (SD = 2.83). Of the 307 children, it was found that 204 (66.4%) had a high DMFT score, which is defined as a score above 4. It was found that 156/307 (51%) children had premature loss of deciduous teeth. CONCLUSION: A high prevalence of premature loss of teeth was found in this study. This finding emphasizes the importance of increasing awareness levels about this issue and focuses attention on the need for more preventive efforts to maintain healthy and normal dentitions that would improve the masticatory function and aesthetics of individuals and the whole population. In addition, the findings emphasize the importance of the early detection of premature loss of primary teeth to prevent future malocclusion.