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Öğe Anatomical landmarks of mandibular interforaminal region related to dental implant placement with 3D CBCT: comparison between edentulous and dental mandibles(Springer France, 2018) Sener, Elif; Onem, Erinc; Akar, Gulcan Coskun; Govsa, Figen; Ozer, Mehmet Asim; Pinar, Yelda; Mert, Ali; Sen, B. Guniz BaksiAnterior mandibular (interforaminal) region is important in implant applications as it serves a basis for neurovascular bedding and holds the prosthesis for patients. Treatment planning for dental implant patients is often complicated by the unknown extent of the anterior loop of the neurovascular bundle. Anatomical structures including mandibular incisive canal (MIC) and lingual foramen (LF) should also be examined as part of the detailed analysis for their neurovascular structures. This study aimed to detect the positions of LF and MIC as well as the prolongation of interforaminal region in Anatolian population to supply the reference data of the surgical safe zone in chin for the clinicians. Mandibles of 70 adult specimens (35 edentulous + 35 dentate) were retrieved from the Department of Anatomy, Ege University. Images of the dry mandibles were obtained using a cone beam computed tomography unit applying a standardized exposure protocol. Afterwards, mandibles were sawn into vertical sections according to the respective tomographic cross-sections. Images were evaluated for the absence/presence of the MIC, its dimensions and antero-posterior length for both edentulous and dentate groups. In addition; the presence, number, location, labial canal and LF diameter and height of the LF were determined for both groups. The MIC was observed in 80 and 68.6% of the dentate and edentulous groups, consecutively (p > 0.05). The MIC continued towards the incisor region in a slightly downward direction. The LF was observed in all dentate mandibles (100%), while it was present in 94.3% of the edentulous mandibles (p > 0.05). For the dentate group, 62.9% of the specimens had two foramens and 20% had three foramens in the mandibular midline. Mean length of the MIC in dentate groups and edentulous groups was measured as 2.55 +/- 0.809 and 3.08 +/- 1.745 mm, respectively. Well-defined MIC mean diameter in dentate groups and edentulous groups were measured as 2.44 +/- 0.702 and 2.35 +/- 0.652 mm, respectively. Significant difference was found between dentate and edentulous group in most of the parameters except for the LF and the diameter of the MIC (p > 0.05). The correlation between observers' measurements ranged between 0.742 and 0.993 for all anatomical landmarks and mandible groups. The MIC and LF are associated with neurovascular bundle variations in number, location and size. Therefore, clinicians should determine each of these anatomical structures on a case-by-case basis to recognize their presence and to take measures for the possible implications of various treatment options. These guidelines included leaving a 2 mm safety zone between an implant and the coronal aspect of the neurovascular bundle. To avoid neurovascular injury during surgery in the interforaminal area, guidelines were developed with respect to validating the presence of an anterior loop of the neurovascular bundle.Öğe Changes in the Fractal Dimension, Feret Diameter, and Lacunarity of Mandibular Alveolar Bone During Initial Healing of Dental Implants(Quintessence Publishing Co Inc, 2012) Onem, Erinc; Baksi, B. Guniz; Sogur, ElifPurpose: To evaluate the combination of fractal dimension (FD), lacunarity, and Feret diameter (FeD) to quantitatively characterize structural changes of mandibular alveolar bone around dental implants during initial healing. Materials and Methods: Three standard-sized regions of interest (ROIs) (mesial and distal crest and apical area) around implants and three ROIs of the same size in the alveolar bone on the contralateral side were analyzed on digital panoramic images. FD was calculated using the box-counting method, and lacunarity was calculated using the FracLac plugin of Image J software. FeD was measured in the same ROIs. Comparisons of the groups were done with the Dunnett test. Results: Forty-two implants in the posterior mandibles of 21 patients were used for FD measurements. A total of 189 ROIs was segmented into binary images. Mean FD values for mesial, distal, and apical ROIs around implants were 1.26, 1.36, and 1.4, respectively. The mean FD of alveolar bone around premolars/molars was 1.39 for all ROIs. The mean FeD for mesial, distal, and apical ROIs around implants was 7.63, 7.86, and 8.02, respectively, whereas it ranged between 7.88 and 8.13 for premolar teeth. Mean lacunarity values for mesial, distal, and apical ROIs around implants were 0.53, 0.51, and 0.48, respectively. Lacunarity values for ROIs around premolars ranged between 0.45 and 0.50. No significant differences were observed in FD, FeD, or lacunarity measurements between ROIs around implants and around teeth. Conclusions: The satisfactory healing of bone following implant placement may be monitored by calculating FD, lacunarity, and FeD using digital panoramic images. Although preliminary, these values may alert the practitioner to any implants with loss of stability. INT J ORAL MAXILLOFAC IMPLANTS 2012;27:1009-1013Öğe Comparison of imaging characteristics of Digora fmx and Digora Optime storage phosphor plate systems(Elsevier Taiwan, 2012) Onem, Erinc; Sogur, Elif; Baksi, B. GunizBackground/purpose: The aim of this study was to compare the physical and psychophysical characteristics of a new generation of the Digora storage phosphor plate (SPP) system [Digora Optime (Soredex, Helsinki, Finland)] with its previous version [Digora fmx (Soredex, Helsinki, Finland)]. Materials and methods: Radiographs of an aluminum test object with a pattern of holes that varied in depth and diameter were exposed to 65 kVp and 10 mA for nine different time settings ranging from a minimum (0.05 seconds) to a maximum (3.2 seconds) using the Digora Optime and Digora fmx SPP systems. For each system, pixel-intensity (the mean gray value) measurements, contrast resolution, and exposure range were determined and compared. In addition, a perceptibility curve test was used to compare the psychophysical properties of the two SPP systems. Repeated-measures of analysis of variance and paired t tests were used to compare the mean gray values and perceptible number of details at each exposure level (P = 0.05). The average measured intraclass correlation coefficient (AMICC) was used to compare inter-rater agreement for the number of perceived details. Results: The mean gray level output of fmx images was higher, whereas the contrast was lower than Optime images at all exposure levels (P < 0.05). Images obtained with the Optime system achieved the best contrast at a lower exposure than that of the fmx images. Digora Optime operated over a wide range of exposures; however, the fmx showed a narrower dynamic range. The number of details perceived on Optime images was significantly higher than that obtained on the fmx images at all exposure levels (P < 0.05). Agreement among observers in terms of the number of perceived details was excellent, with the AMICC ranging from 0.845-0.889. Conclusion: Digora Optime achieved the best contrast at a lower exposure and demonstrated a better dose response. In addition, the perceptibility of low-contrast details was significantly higher for Digora Optime at a wide range of exposures. Copyright (c) 2012, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC. All rights reserved.Öğe Comparison of quantitative radiomorphometric predictors of healthy and MRONJ-affected bone using panoramic radiography and cone-beam CT(Oxford Univ Press, 2024) Aslan, Elif; Onem, Erinc; Mert, Ali; Baksi, B. GunizObjectives To determine the most distinctive quantitative radiomorphometric parameter(s) for the detection of MRONJ-affected bone changes in panoramic radiography (PR) and cone-beam CT (CBCT). Methods PR and sagittal CBCT slices of 24 MRONJ patients and 22 healthy controls were used for the measurements of mandibular cortical thickness (MCT), fractal dimension (FD), lacunarity, mean gray value (MGV), bone area fraction (BA/TA), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular number (Tb.N). MCT was measured in the mental foramen region. While FD and lacunarity were measured on mandibular trabecular and cortical regions-of-interest (ROIs), the remaining parameters were measured on trabecular ROIs. The independent samples t-test was used to compare the measurements between the MRONJ and control groups for both imaging modalities (P = .05). Results MCT was the only parameter that differentiated MRONJ-affected bone in both PR and CBCT (P < .05). None of the remaining parameters revealed any difference for MRONJ-affected bone in CBCT (P > .05). FD, lacunarity, MGV, BA/TA, and Tb.Sp could distinguish MRONJ-affected trabecular bone in PR (P < .05). The correspondent ROI for both imaging methods that was reliable for detecting MRONJ-affected bone was the trabecular bone distal to the mental foramen above the inferior alveolar canal (ROI-3). Conclusions MCT is a reliable parameter for the discrimination of MRONJ-affected bone in both PR and CBCT images. PR may be used to detect MRONJ-affected trabecular bone using FD, lacunarity, MGV, BA/TA, and Tb.Sp measurements as well.Öğe Construction of a copper stepwedge with aluminum equivalent mean gray values(Univ Sao Paulo Fac Odontologia Bauru, 2010) Dundar, Nesrin; Guneri, Pelin; Onem, Erinc; Boyacioglu, HayalObjectives: To produce a copper (Cu) stepwedge with aluminum (Al) equivalent mean gray values (MGV). Material and Methods: The thicknesses of Cu steps that were equivalent to those of the Al were formulated using the X-ray attenuation properties of the materials. The Al and fabricated Cu stepwedges were radiographed, but the MGVs of the Cu stepwedge were mismatching to those of the Al. Using a mathematical function to adjust the pixel MGV of Cu stepwedge to those of the Al, new Cu stepwedges were created. In vitro iterations were performed until best approximation to Al was reached. Results: The MGV of the Cu stepwedges fabricated by formularization were different than those of Al (p=0.001). Iteration method led to MGV similar to those of the Al stepwedge (p=0.207). Conclusions: Construction of a Cu stepwedge according to the basic rules of radiophysic failed to result in a stepwedge with similar radiodensity values to those of Al stepwedge. Further studies may use the formularization method only for prototype Cu wedge production, but consecutive iterations shall be compassed to obtain the best approximation to Al MGV.Öğe Detection of artificial demineralization bordering different types of laminate veneers using visual inspection and storage phosphor radiography(Springer Heidelberg, 2013) Comlekoglu, Erhan; Onem, Erinc; Comlekoglu, Mine Dundar; Baksi, B. Guniz; Mert, AliThe objective of this study is to compare the diagnostic accuracy of visual inspection (VI) and storage phosphor plate (SPP) radiography for the detection of artificial demineralization bordering different laminate veneers. Twenty human maxillary canine teeth were prepared. All-ceramic (A) and hybrid ceramic (H) laminate veneers were fabricated and luted. Veneered teeth were covered except for a circular window on the proximal surface bordering restorations. Teeth were kept in acetic acid buffer to create demineralization and imaged with a SPP system. Ten observers evaluated all teeth first visually then with SPP images for the presence/absence of demineralization. Teeth were examined using scanning electron microscopy (SEM) as well. The accuracy was expressed as the area under the ROC curves (A (z)). Pair-wise comparisons were performed using two-way ANOVA and post hoc t test (p = 0.05). Fleiss kappa (kappa) was used for agreement. SPP radiography was better than the VI for both veneers (p = 0.004). The A (z)s of two veneers were different for both VI (p < 0.005) and SPP (p < 0.005). SEM evaluation revealed lesions confined to enamel. kappa was fair for H, and fair to moderate for A. Agreement was higher for the radiographic evaluation for both veneers. Enamel demineralizations bordering hybrid and ceramic laminate veneers can be detected better with SPP radiography than VI and detectability was better for all-ceramic veneers than the hybrid ceramic ones. Early detection of enamel demineralizations bordering laminate veneers would result in time-saving and less-invasive treatment methods; therefore, SPP radiography may be recommended in clinically suspicious cases since it provides better diagnostic accuracy.Öğe Diagnostic accuracy of Digora Optime storage phosphor plates for proximal subsurface demineralization: effect of different exposure times(Elsevier Science Inc, 2012) Onem, Erinc; Baksi, Guniz; Sen, B. Hankan; Mert, AliObjective. The aim of this study was to compare the diagnostic accuracy of F-speed film and storage phosphor plate (SPP) exposed with different exposure times for the detection of artificial enamel subsurface demineralization. Study Design. Standard enamel windows of extracted premolars were exposed to a demineralizing solution. All teeth were radiographed before and after acid application with F-speed films and SPPs. Films were exposed for 0.25 seconds and SPPs were exposed using 4 exposure times. Receiver operating characteristic analysis was used for diagnostic accuracy (A(z)). Results. Significant differences were obtained among A(z)s of 0.08-versus 0.12-seconds and 0.10-versus 0.12-second exposed SPPs (P < .05). A(z)s of films were higher than the SPPs exposed with 0.08, 0.10, and 0.12 seconds (P < .05). No difference was found between the A(z)s of the 2 systems when SPPs were exposed for 0.16 seconds (P > .05). Conclusions. Diagnostic accuracy of films and SPPs was not impaired when exposure time was 36% reduced for the latter; however, diagnosis was impaired when reduced 52%. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:e78-e84)Öğe Effect of Mandibular Angulation on Pre-Implant Site Measurement Accuracy Using CBCT(Quintessence Publishing Co Inc, 2021) Onem, Erinc; Baksi, B. Guniz; Turhal, R. Irmak; Sen, B. HakanPurpose: To evaluate the accuracy of available bone width, height, and length measurements on preplanned implant sites using cone beam computed tomography (CBCT) images scanned at different angulations of the mandible. Materials and Methods: Standard cylindrical holes were prepared on six dry human mandibles and filled with warm gutta-percha to create spherical markers for measurements of available bone width, height, and length. Mandibles were first scanned with a CBCT device in the ideal position with the occlusal plane parallel to the horizontal plane. Then, images of the mandibles were obtained in rotation, tilt, flexion, and extension positions using 5-and 10-degree angulations. Measurements were done on a total of 54 images. Original dimensions of the available bone for planned implant sites were measured with a digital caliper on dry mandibles as the gold standard. The absolute values of the differences between each measurement and the gold standard were obtained for measurement errors. Repeated-measures analysis of variance and Dunnett's multiple comparisons test were used for comparisons (P=.05). Intraobserver and interobserver agreement was calculated using intraclass correlation coefficient (ICC). Results: ICC was excellent for both intraobserver and interobserver reproducibility. No significant difference was found between length and height measurements in the ideal position and in rotation, tilt, flexion, and extension movements of mandibles at two different angulations (P > .05). Width measurements revealed a significant difference among the ideal position and measurements at the 10-degree flexion, 10-degree extension, 10-degree rotation, and 10-degree tilted mandibular positions (P < .05). Conclusion: The position of the occlusal plane with respect to the floor during the CBCT scan may have a clinically significant effect on dental implant site dimensions.Öğe Effect of Tube Current on Linear Measurement Accuracy of Cone Beam Computed Tomography Images(Bentham Science Publ Ltd, 2018) Sener, Elif; Onem, Erinc; Mert, Ali; Baksi, B. GunizObjective: To compare the accuracy of linear bone measurements on Cone Beam Computed Tomography (CBCT) images obtained using different tube currents. Methods: Twelve reference points were prepared by using burs and heated gutta-percha on each of the ten dry mandibles for horizontal and vertical measurements on anterior and posterior segments. Images were obtained with Kodak 9000 3D cbct system at 5 different tube currents (2 mA, 3.2 mA, 6.3 mA, 10 mA and 15 mA). Three radiologists did total of 1200 linear measurements. True lengths were determined with a digital caliper. Height and width measurements from each of the mA settings were compared to the gold standard using Bland and Altman plots. Overall comparison of the measurements was done using repeated measures ANOVA. Correlation between individual measurements of each observer was assessed with Pearson's correlation analysis. Results: No differences were found in the height and width measurements for both anterior (p>0.05) and posterior (p>0.05) measurements for different mA settings. Increase in mA caused an increase in the geometric accuracy of cbct images (p>0.05). Mean deviations from the gold standard ranged between -0.7 and +0.12 mm among the lowest and highest tube settings. The correlation between observers' measurements ranged between 0.97 and 0.98 for increasing tube settings. Conclusion: Tube current may be reduced as low as 2mA without jeopardizing linear measurement accuracy.Öğe Postgraduate Dental Students' Knowledge Levels Toward Medication-Related Osteonecrosis of the Jaws(Marmara Univ, Inst Health Sciences, 2023) Aslan, Elif; Sener, Elif; Onem, Erinc; Mert, Ali; Cankaya, HuelyaObjective: Medication-related osteonecrosis of the jaws (MRONJ), is often described as a side-effect of bisphosphonates within the dental school curriculum. However, as highlighted in the current literature, some antiresorptive and antiangiogenic drugs may also cause MRONJ. This study aimed to investigate the awareness and knowledge of post-graduate dental students (PDSs) from different specialty/doctoral programs towards MRONJ.Methods: An electronic questionnaire containing 28 questions in 3 different sections focusing on demographic characteristics, general information, and clinical attitude, was prepared. Two-thousand PDSs from 27 universities were invited to participate in the survey in December 2021. The obtained data were evaluated statistically using descriptive statistics and the Chi-Square test (p=.05).Results: The response rate of the survey was 10%. The number of PDSs showed a homogeneous distribution for each specialty, whereas the number of women participants was higher than that of men (p<.05). In the general information section, the highest correct answer rates belonged to students from Oral and Maxillofacial Surgery and Oral and Maxillofacial Radiology departments. However, there was no statistically significant difference between different dental specialties regarding correct answer rates (p>.05). PDSs had higher rates of correct answers to general information questions about antiresorptive drugs than for antiangiogenic drugs. 92% of participants stated that they obtained their knowledge about MRONJ from their undergraduate education.Conclusion: The findings of this study reveal the necessity of updating the dental school curriculum in line with the current literature on MRONJ, as well as including more postgraduate courses on MRONJ during the specialty/doctoral education period.
