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    Investigation of mandibular fractal dimension on digital panoramic radiographs in bruxist individuals
    (Elsevier Science Inc, 2021) Eninanc, Ilknur; Yeler, Defne Yalcin; Cmar, Ziynet
    Objective. This study aimed to evaluate changes in mandibular trabecular bone structure in bruxism using fractal analysis on digital panoramic radiographs obtained with automatic dosing. Study Design. In this prospective study, fractal analysis was performed on radiographs of 126 bruxists and 126 non-bruxists. Eight paired mandibular regions of interest were selected: the bilateral condylar and gonial regions, and the bilateral dentate regions between the apical areas of the first molar and second premolar and between the first premolar and canine. Fractal dimensions (FDs) were calculated at each site. Results. Mean FD values in the bilateral gonial regions of the bruxists were significantly lower than those of controls (P <= .049). In both groups, FD values of the right dentate region anterior to the mental foramen were significantly lower than those on the left side (P <= .042). Females exhibited significantly lower FD values in both condylar regions in both groups (P <= .039) and in the right dentate regions in the controls (P <= .022). Correlations between age and FD in all regions were positive but nonsignificant in both groups (P > .05). Conclusions. FD values of mandibular trabecular bone are affected by bruxism in the gonial region and by laterality and sex differences in the condylar and dentate regions.
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    Structural changes in periodontium of rats exposed to a low concentration of hydrogen sulfide for 50 days
    (SAGE PUBLICATIONS INC, 2016) Yeler, Defne Yalcin; Hocaoglu, Turgay; Koraltan, Melike; Aydin, Murat; Gul, Mehmet; Gul, Semir
    The aim of the present study was to investigate the effect of H2S inhalation at a low concentration (at human equivalent dose of pathologic halitosis) on rat periodontium over a long term (50 days). The threshold level of pathologic halitosis perceived by humans at 250 ppb of H2S was converted to rat equivalent concentration (4.15 ppm). Rats in the experimental (H2S) group (n = 8) were exposed to H2S continuously but not the control rats (n = 8). After 50 days, periodontal tissue samples were taken from the mandibular first molar region and examined histopathologically to determine inflammatory cell infiltration (ICI), osteoblastic activities, number of osteoclasts, and resorption lacunae. Sulcular epithelium layer destruction was observed in the H2S group. Frequency of ICI was significantly higher in the H2S group compared to the control group (P < 0.05). The number of osteoclasts were found significantly higher in the H2S group (34.28 +/- 3.28) compared to the control group (8.85 +/- 1.85) (P < 0.05) and the number of resorption lacunae were also higher in the cementum tissue (6.1 +/- 2.4) and alveolar bone (3.8 +/- 1.5) versus their corresponding control groups (1.6 +/- 0.5 and 1.4 +/- 0.5, respectively) (P < 0.05). There were no statistically significant differences between the two groups with regard to osteoblastic activity. H2S inhalation induces inflammatory changes in the periodontium as well as resorption of the alveolar bone and cementum tissue in rats. These histopathologic changes in periodontal tissues support the idea that long-term H2S inhalation may have a destructive effect on periodontal tissues.
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    A survey on the potential relationships between TMD, possible sleep bruxism, unilateral chewing, and occlusal factors in Turkish university students
    (TAYLOR & FRANCIS LTD, 2017) Yeler, Defne Yalcin; Yilmaz, Nurbengu; Koraltan, Melike; Aydin, Ezgi
    Objective: To evaluate whether there is a relationship between possible sleep bruxism (PSB), temporomandibular disorders (TMD), unilateral chewing (UC), and occlusal factors in university students recruited from Cumhuriyet University in Turkey. Methods: For this cross-sectional survey, 519 (223 males, mean age 21.57 +/- 2.3 years, 296 females, mean age 21.02 +/- 2 years) university students who admitted to the Department of Oral and Maxillofacial Radiology of the Faculty of Dentistry, Cumhuriyet University for dental care between 2012 and 2014 were selected randomly. Students were asked to complete a questionnaire form including questions about TMD, PSB and UC. Presence and direction of malocclusion were recorded during clinical examination. Chi-square test was used for statistical analysis. Results: It was found that 96.6% of the students with PSB had TMD (p<0.05). The prevalence of severe TMD was high among students with PSB. There was a significant association between UC, PSB and TMD (p<0.05). No statistically significant association was found between occlusal factors and PSB and TMD (p>0.05). Conclusion: Sleep bruxism, which heavily depends on self-report, is significantly associated with TMD. Unilateral chewing seems to be a common factor for development of SB and TMD. However, further studies are needed to corroborate this finding. Additionally, this study supports the hypothesis that occlusal factors are not related to self-reported sleep bruxism.
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    Systemic effects of H2S inhalation at human equivalent dose of pathologic halitosis on rats
    (TAYLOR & FRANCIS LTD, 2017) Yeler, Defne Yalcin; Aydin, Murat; Gul, Mehmet; Hocaoglu, Turgay; Ozdemir, Hakan; Koraltan, Melike
    Objectives: Halitosis is composed by hundreds of toxic gases. It is still not clear whether halitosis gases self-inhaled by halitosis patients cause side effects. The aim of the study was to investigate the effect of H2S inhalation at a low concentration (human equivalent dose of pathologic halitosis) on rats. Materials and methods: The threshold level of pathologic halitosis perceived by humans at 250ppb of H2S was converted to rat equivalent concentration (4.15ppm). In the experimental group, 8 rats were exposed to H2S via continuous inhalation but not the control rats. After 50 days, blood parameters were measured and tissue samples were obtained from the brain, kidney and liver and examined histopathologically to determine any systemic effect. Results: While aspartate transaminase, creatine kinase-MB and lactate dehydrogenase levels were found to be significantly elevated, carbondioxide and alkaline phosphatase were decreased in experimental rats. Other blood parameters were not changed significantly. Experimental rats lost weight and became anxious.Histopathological examination showed mononuclear inflammatory cell invasion in the portal areas, nuclear glycogen vacuoles in the parenchymal area, single-cell necrosis in a few foci, clear expansion in the central hepatic vein and sinusoids, hyperplasia in Kupffer cells and potential fibrous tissue expansion in the portal areas in the experimental rats. However, no considerable histologic damage was observed in the brain and kidney specimens. Conclusions: It can be concluded that H2S inhalation equivalent to pathologic halitosis producing level in humans may lead to systemic effects, particularly heart or liver damage in rats.
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    The relationship of medial sigmoid depression and sigmoid notch morphology with vertical and sagittal growth patterns in Turkish population
    (Soc Anatomica Espanola, 2024) Gurleyuk, Ali Canturk; Yeler, Defne Yalcin; Eninanc, Ilknur; Yeler, Hasan
    Medial sigmoid depression (MSD) is an anatomical variation located just below the deepest point of the sigmoid notch (SN). The etiology of MSD is unknown. It has been reported that increased maximum bite force affects the occurrence of MSD, and vertical growth pattern affects SN morphology. The aim of this study was to investigate the effects of these malocclusions on the presence and morphology of MSD and SN, since bite force can change with vertical and sagittal growth patterns. This is the first study to investigate the effects of vertical growth pattern on the presence and morphology of MSD, and the effects of sagittal growth pattern on SN morphology. Panoramic and lateral cephalometric radiographs of a total of 634 (427 female, 207 male) patients aged from 18 to 35 years (mean 19.58) were included in this retrospective study. MSD and SN shapes, SN depth and width were evaluated on panoramic radiographs. Mann Whitney -U, Kruskal-Wallis and Chi-square tests were used for data analysis. Sagittal and vertical growth patterns were not significantly associated with the presence and shape of MSD (p>0.05). SN depth was greater in individuals with class III malocclusion, and both SN depth and width were lower in hyperdivergent individuals. There was no significant relation- ship between SN shapes and vertical and sagittal growth patterns (p>0.05). SN depth is affected by both vertical and sagittal growth pattern, and SN width is affected only by vertical growth pattern. The presence of MSD was not associated with growth pattern.
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    Ultrastructural changes in epithelial cells of rats exposed to low concentration of hydrogen sulfide for 50 days
    (TAYLOR & FRANCIS INC, 2016) Yeler, Defne Yalcin; Aydin, Murat; Hocaoglu, Peyami Turgay; Koraltan, Melike; Ozdemir, Hakan; Kotil, Tugba; Gul, Mehmet
    Hydrogen sulfide (H2S) and other volatile sulfur compounds (VSCs) appear mainly in the oral air of patients with halitosis. It seems that VSCs are directly involved in the pathogenesis of gingival diseases. In previous studies, short-term (7 hours-4 days), high concentrations (5-400 ppm) of H2S applications on periodontal tissues have been evaluated in a culture medium. The aim of the present study was to investigate the potential effects of lower (equivalent to halitosis) concentrations of H2S on rat gingival tissue for longer-term inhalation. The threshold level of pathologic halitosis perceived by humans at 250 ppb of H2S was converted to rat equivalent concentration (4.15 ppm). Rats in the experimental (H2S) group (n=8) were exposed to H2S continuously but not the control rats (n=8). After 50 days, the gingival sulcular tissue samples of each rat were taken and examined using transmission electron microscope. Ultrastructural changes in the sulcular epithelia of the rat gingiva showed deformation of celullar shape, vacuolization, and disintegrity of intercelullar connection by loss of desmosomes and collagen fibrils. No basal membrane damage was observed. Inhalation of low levels of H2S (equivalent of halitosis) in the oral environment causes ultrastructural celullar damages in rat sulcular mucosa. These results suggest that halitosis may be the potential reason for periodontal destruction in humans.