Investigation of the Effect of Local and Systemic Preoperative Dexamethasone Application on Bone Tissue Healing in Mandibular Bone Defects.

OBJECTIVES: The aim of this study was to investigate the effect of locally and systemically delivered single-dose corticosteroid injections on bone tissue. STUDY DESIGN: A total of 84 Wistar albino rats were divided into 2 groups as local and systemic injection groups, and 2 groups as control and experiment among themselves. Before the procedure, dexamethasone was given to the experimental group and physiological saline was given to the control group. A defect was created in the jawbone. It was sacrificed on the third, seventh, and 40th days. The mandible bones of the sacrificed rats were removed and the healing of the bone tissue was examined histopathologically. RESULTS: No significant difference was observed in the tissue sections of the subjects sacrificed after 40 days. However, the increase in fibroblastic connective tissue and the number of osteoblasts were less in the experimental local groups that were sacrificed after 7 days compared with the control groups (P=0.040 and 0.041). Again, it was determined that there was a statistically significant decrease in the experimental local group compared with the experimental systemic group (P=0.040 and 0.004). CONCLUSIONS: It can be said that single-dose corticosteroid applications cause a delay in bone healing in the early period.

Land cover change detection in the Turkish coastal zone based on 28-year (1990-2018) Corine data.

In this research, land cover changes in the coastal region of Turkey were analyzed using the Corine dataset between 1990 and 2018. Changes in each period were analyzed by using the rate of change and the annual rate of change, the transition matrix of net changes, and the transition probability matrix. In order to predict land cover change trends and to determine future land cover change probabilities, a combination of Markov and cellular automata models was used. It was determined that the highest increase in each study period was in artificial surfaces and the highest decrease was in the forest and the semi-natural area. The total forest areas were converted to the other land cover type in the first study period amounting to 2479.32 km2. Also, it was decreased and transformed by about 62.47 km2, 118.82 km2, and 203.09 km2 of the forest area that existed in the second, third, and fourth periods respectively. The results indicate that the probabilities of the increasing area will be covered by artificial surfaces and agricultural areas. It is estimated that the rate of 57% in 1990, the initial year of the forest areas, will decrease to 53.4% in 2034 and to 53% in 2050. Also, the rate of 2.1% in 1990, the initial year of the artificial surfaces, will increase to 4.5% in 2034 and to 5.0% in 2050. It is seen that more artificial surfaces will be needed in the Turkish coastal region due to the increasing population and number of tourists. It is important to evaluate and investigate the coastal areas where more artificial areas are expected to be needed within the scope of the coastal area management plans to be prepared at the national scale.

Summer season sea surface temperature changes in the Aegean Sea based on 30 years (1989-2019) of Landsat thermal infrared data.

In this research, sea surface temperature (SST) variability for the summer season in the Aegean Sea was analysed over a period of 30 years by using the Landsat thermal infrared bands. A total of 88 Landsat 5, 7, and 8 thermal infrared satellite images from June, July, and August were used for each year from 1989 to 2019. To estimate SST from the thermal infrared band data, thermal infrared sensor at-sensor spectral radiance, and thermal infrared sensor top-of-atmosphere brightness temperatures were used. SST pixel values were extracted from thermal images for the 3-month summer season of each year. In order to validate the findings, regression analysis was performed between the Mediterranean Sea Ultra High Resolution SST L4 data and Landsat data for the 2008-2019 period. Regression constant R-squared values were found to be 0.9672 for June, 0.9550 for July, 0.9634 for August, and 0.9634 for all summer seasons. It was calculated that the minimum value of the average SST was 18.44 ± 2.87 °C in 1992, and the maximum value of the average SST was 23.45 ± 0.70 °C in 2018. According to the Landsat data, over the past 30 years, the annual average SST changes were estimated to be 0.11 °C, and the total changes of average SST were estimated to be 3.19 ± 1.26 °C. As a result of the analysis and the validation, we can see that there is a rising trend in sea surface temperature in the Aegean Sea. However, it is difficult to determine whether this upward trend is related to global climate change.

Evaluation of biochemical variables in patients with recurrent aphthous stomatitis.

PURPOSE: We investigated the effects of various biochemical agents on the etiopathogenesis of recurrent aphthous stomatitis (RAS). METHODS: We enrolled 70 RAS patients and 70 healthy volunteers. Peripheral venous blood samples were collected. We performed complete blood counts, then measured the levels of ferritin, vitamin B12, iron, magnesium, phosphorus, calcium, thyroid-stimulating hormone, T3, T4, and 25-hydroxy D3. RESULTS: The groups did not differ in terms of age (p = 0.912) or sex (p = 0.612). The levels of ferritin and 25-hydroxy vitamin D were significantly lower in RAS patients (both p Ë‚ 0.05). CONCLUSION: Vitamin D and/or ferritin deficiency may induce RAS. Measurements of vitamin D and ferritin may assist diagnosis and follow-up.

Expression pattern of hypoxia-related genes in odontogenic cysts.

OBJECTIVE: The aim of the present study was to reveal the effects of hypoxia-associated signaling in odontogenic cysts. DESIGN: The expression levels of genes involved in the hypoxia-associated signaling pathway were determined by quantitative Polymerase Chain Reaction (PCR) method. RESULTS: As a result, it was found that phosphatase and tensin homolog (PTEN) expression was low (p = 0.037), and the expression levels of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) (p = 0.0127), hypoxia inducible factor 1 alpha (HIF1A) (p < 0.001), and HIF1A antisense RNA 1 (HIF1A-AS1) (p = 0.0218) were higher in cyst tissue compared to normal tissue. HIF1A gene expression was found to be significantly altered according to the pathologic subtypes of odontogenic keratocyst, dentigerous cyst, and radicular cyst. CONCLUSIONS: Odontogenic cysts were found to have higher expression of HIF1A and HIF1A-AS1, which may be related to the increased hypoxia in these lesions. In addition, PI3K/Akt signaling may be stimulated by increased PIK3CA and decreased PTEN expression, which promote cell survival and support the mechanism of cyst formation.

Inflammation-associated long non-coding RNA signature in radicular cyst tissues.

Radicular cysts are characterized by significant levels of changes in inflammatory biomarkers. Among them, interleukins and growth factors have been reported to be deregulated in radicular cyst tissues. Moreover, long non-coding RNAs are recently discovered non-coding RNA molecules that regulate various intracellular stimuli to keep homeostasis in balance. A growing body of evidence suggests that lncRNAs are significantly involved in the regulation of inflammation by targeting various inflammatory biomarkers. Accordingly, the present study was aimed to investigate the gene expression levels of inflammation-related lncRNAs in radicular cysts and show their possible roles in the development of radicular cysts. For the study, a total of 25 patients with a radiologically and pathologically confirmed radicular cyst were enrolled. For the determination of non-coding RNA expression levels, real-time qPCR was used. As a result of the current study, expression levels of PACER and THRIL were found to be significantly elevated in radicular cyst tissues compared to control tissue samples. However, MALAT1, ANRIL, and NEAT1 expression levels were not significantly altered in radicular cyst tissues compared to control tissue samples. In conclusion, long non-coding RNAs, PACER and THRIL, seem to have significant pathophysiological roles by acquiring molecular changes during inflammation and might be involved in the development and formation of radicular cysts.

Is the YouTube™ a useful resource of information about orthognathic surgery?: A cross-sectional study.

PURPOSE: YouTube™ has become a widely used resource of information about health-related topics nowadays. This cross-sectional study has aimed to analyze the content and quality of YouTube™ videos on orthognathic surgery. METHODS: In our study, six orthognathic surgery-related keywords (Le Fort I osteotomy, sagittal split osteotomy, jaw surgery, jaw correction surgery, orthodontic surgery, and orthognathic surgery) were used to search on YouTube™. Only the videos in English, which had visually and audibly acceptable quality and were mainly about orthognathic surgery, were chosen from the videos. A total of 360 videos were selected, the top 60 videos for each search term, and sorted according to view count. Of these videos, the first 60 videos were analyzed. Video source (independent or educational), duration, number of views, likes, and dislikes were recorded for each video. Moreover, two impartial observers evaluated the visibility, popularity, quality, usefulness, and reliability of the videos. RESULTS: 41 of 60 videos were of independent sources while 19 of them were of educational origin. Information content of the videos was found to be insufficient. No significant difference was determined between independent and educational videos in terms of popularity, visibility, usefulness and quality analysis of the videos (p > 0.05), but a significant difference was found in terms of reliability values (p < 0.05). CONCLUSION: It can be said that YouTube™ videos were not a reliable and accurate enough source of information when evaluated in terms of orthognathic surgery-related content and quality. Therefore, the information content provided by specialists and health institutions, in particular, should be increased in number, thereby making access to better quality information on orthognathic surgery easy for patients.