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OBJECTIVES: This in vitro study aimed to investigate leakage of mercury from amalgam restorations after cone beam computed tomography (CBCT) and magnetic resonance imaging (MRI) examinations. STUDY DESIGN: In total, 238 amalgam disks were prepared and placed in saline solution. The samples were allocated randomly to 7 groups, with 34 samples in each group. CBCT imaging was performed for 4 groups with different imaging parameters (narrow/wide field of view [FOV]; standard/high-resolution). MRI procedures were performed with 3.0-T and 1.5-T magnetic field strengths. No imaging was performed for the samples in the control group. The amalgam samples were removed from the tubes 24 hours after imaging and submitted for plasma mass spectrometry analysis. Kruskal-Wallis and Dunn's tests were performed to compare data. A P value less than .05 was accepted as statistically significant. RESULTS: The highest mean mercury value was found in the 3.0-T MRI group, whereas the lowest mean value was found in the narrow FOV, standard-resolution CBCT group. There were no significant differences between the control group and the experimental groups (P ≥ .338) or between the experimental groups (P > .05). CONCLUSIONS: CBCT and MRI procedures similar to those used in patient care caused no significantly different mercury release compared with nonexposed samples.

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OBJECTIVES: The aims of this study were to determine the prevalence of maxillary sinus retention cysts (MSRCs) and to evaluate the effects of mean temperature and mean air humidity on the prevalence of MSRCs in two cities in Turkey. METHODS: This retrospective study was conducted in Antalya and Erzurum, two cities with different air humidities and temperatures in Turkey. Panoramic images of patients who visited the Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Akdeniz University and Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Ataturk University for diagnostic purposes were evaluated. A total of 4800 panoramic images were included in the study. The mean age of the patients was 27.03 ± 6.48 years. The prevalence of MSRCs was analyzed according to sex, mean temperature, and mean air humidity. Values of p < 0.05 were considered statistically significant. RESULTS: Among the 4800 panoramic images evaluated, 228 indicated the presence of MSRCs. MSRCs were found significantly more frequently in males than in females. The prevalence was 3% in Antalya and 6.5% in Erzurum, with a total prevalence of 4.8%. While there was a significant correlation between the total amount of cysts and monthly mean air humidity in Erzurum, the correlation effect size was very low. CONCLUSIONS: The total prevalence of MSRCs was 4.8%. There were no correlations between the frequency of MSRCs and the mean air humidity or mean temperature.

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Objective To compare the differences in masticatory muscle volume and occlusal force distribution between patients with sleep bruxism (SB) and healthy individuals. Methods The study was performed on 14 SB patients and 12 controls aged between 20 and 27 years. Magnetic resonance images from a previous clinical trial were used for volumetric measurements of masticatory muscles. Distribution of bite forces was recorded using T-Scan® II. T-tests were used for data comparison. Results The mean age of the subjects was 23 ± 1.85 years. The mean muscle volumes of patients with SB and healthy subjects were 177.3 and 185.9 cm3, respectively. The mean occlusal force areas were 72.4 pixels and 89.8 pixels for patients with SB and healthy subjects, respectively. There was no significant difference in measurements between groups (p > 0.05). Conclusion There was no significant difference in the distribution of masticatory muscles and occlusal force between young patients with SB and healthy subjects.

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Purpose To evaluate ex vivo mercury release from dental amalgam after 7.0-T and 1.5-T MRI. Materials and Methods The authors evaluated 60 caries-free molar or premolar teeth that had been extracted for clinical indications. Two-sided cavities were opened in each tooth and amalgam fillings applied. After 9 days, two groups of 20 randomly selected teeth were placed in 20 mL of artificial saliva immediately followed by 20 minutes of MRI exposure at 1.5 or 7.0 T. A control group of teeth was placed in artificial saliva without undergoing MRI exposure. The teeth were removed from the artificial saliva 24 hours later, and the saliva was analyzed for mercury content by using inductively coupled plasma mass spectrometry. One-way analysis of variance was used to compare the mean mercury values among the three independent groups, and the Tukey test was used for multiple comparisons of the mean values. Results The mean mercury content of the artificial saliva was 673 µg/L ± 179 in the 7.0-T MRI group, 172 µg/L ± 60 in the 1.5-T MRI group, and 141 µg/L ± 152 in the control group. The mercury content in the 7.0-T group was greater than that in both the 1.5-T group (P < .001; 95% confidence interval: 368 µg/L, 633 µg/L) and the control group (P < .001; 95% confidence interval: 416 µg/L, 648 µg/L). There was no statistically significant difference in mercury content between the 1.5-T and control groups (P = .84; 95% confidence interval: -164 µg/L, 110 µg/L). Conclusion In an ex vivo setting, mercury was released from amalgam fillings after exposure to 7.0-T MRI but not 1.5-T MRI.

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OBJECTIVES: The purpose of this study was to assess the pattern of third molar impaction and associated symptoms in a Central Anatolian Turkish population. MATERIAL AND METHODS: A total of 2,133 impacted third molar teeth of 705 panoramic radiographs were reviewed. The positions of impacted third molar teeth on the panoramic radiographs were documented according to the classifications of Pell and Gregory and of Winter. The presence of related symptoms including pain, pericoronitis, lymphadenopathy and trismus was noted for every patient. Distributions of obtained values were compared using the Pearson χ2 test. Nonparametric values were analyzed using the Mann-Whitney U test and Kruskal-Wallis test. RESULTS: The mean age of the subjects was 30.58 ± 11.98 years (range: 19-73); in a review of the 2,133 impacted third molar teeth, the most common angulation of impaction in both maxillaries was vertical (1,177; 55%). Level B impaction was the most common in the maxilla (425/1,037; 39%), while level C impaction was the most common in the mandible (635/1,096; 61%). Pain (272/705; 39%) and pericoronitis (188/705; 27%) were found to be the most common complications of impaction. Among 705 patients (335 males, 370 females), pericoronitis was more prevalent in males (101; 30%) and usually related to lower third molars (236; 22%). The retromolar space was significantly smaller in females (p < 0.05). Moreover, there was a significant difference in retromolar space for the area of jaw (maxillary: 11.3 mm; mandibular: 14.2 mm) and impaction level (A: 14.7 mm; B: 11.1 mm; C: 10.3 mm; p < 0.05). CONCLUSION: The pattern of third molar impaction in a Central Anatolian Turkish population was characterized by a high prevalence rate of level C impaction with vertical position. Pain and pericoronitis were the most common symptoms usually associated with level A impaction and vertical position.

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BACKGROUND: The aim of the present study is to evaluate the efficacy of CBCT in volume measuring using Stafne Bone Cavities (SBC) as an example. MATERIAL AND METHODS: The study was conducted with 14 subjects with SBC detected on panoramic radiographs. In order to evaluate lesions volumetric dimensions, CBCT images for each patient were captured. Files in Digital Imaging and Communications in Medicine (DICOM) format were transferred into a medical image processing program (ITK-SNAP 2.4.0) and volume in mm3 of the cavities were measured using semi-automatic segmentation procedure by 2 observers blinded to each other over a one-month period. Inter-reliability of volumetric measurements between observers was compared. SBCs relation to mandibular canal was also examined and three types of relation were observed; type 1: mandibular canal is separated from the SBC, type 2: mandibular canal is in contact with SBC, type 3: mandibular canal goes through the SBC. RESULTS: There were 12 males and 2 females who had SBC in this study (age range: 37-73, mean age: 55.3 years). The total volume of SBC in patients ranged from 160 mm3 to 520 mm3 (mean: 361.7 mm3). There was no significant difference between observers for volume measurements (p>0.05). According to relationship of SBC with mandibular canal, most SBCs were Type 1 (64.3 %) followed by type 3 (21.4 %) and type 2 (14.3 %). Pearson correlation coefficient shows a positive correlation between lesions volumetric size and relation with mandibular canal (pearson correlation = 0.54, sig < 0.05). CONCLUSIONS: Based on the results of this preliminary study, CBCT was considered to be an effective radiographic technic for measuring volumetric sizes of SBCs. However further studies with larger sample sizes are needed to prove the usefulness of CBCT in volume measurements.

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OBJECTIVE: To present two cases of osteochondritis dissecans (OCD) in temporomandibular joints (TMJs) evaluated by panoramic radiography and cone-beam computed tomography (CBCT). CLINICAL PRESENTATION AND INTERVENTION: Two patients were referred to the Oral and Maxillofacial Radiology Clinic with pain, preauricular tenderness on the TMJ region and limitation of mandibular movements. An earlier panoramic radiograph revealed radiopaque lesions adjacent to the condyles. CBCT images were obtained from patients to assess the radiopacities. The CBCT scan detected irregular-type radiopaque lesions on anterior and superior aspects of the right condyle as well as degenerative osseous changes on both TMJs. CONCLUSION: The CBCT images revealed degenerative osseous changes and loose bodies on TMJs. The lesions were diagnosed as OCD with the help of trauma history, as well as clinical and radiographic findings.

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The purpose of this article is to present the case of maxillofacial trauma patient with maxillary sinus fracture diagnosed with cone-beam computed tomography (CBCT) and to explore the applications of this technique in evaluating the maxillofacial region. A 23-year-old male patient attempted to our clinic who had an injury at midface with complaints of swelling, numbness. The patient was examined before in emergency center but any diagnosis was made about the maxillofacial trauma. The patient re-examined clinically and radiographically. A fracture on the frontal wall of maxillary sinus is determined with the aid of CBCT. The patient consulted with the department of maxillofacial surgery and it is decided that any surgical treatment was not necessary. The emerging technique CBCT would not be the primary choice of imaging maxillofacial trauma. Nevertheless, when advantages considered this imaging procedure could be the modality of choice according to the case.

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OBJECTIVES: The aim of the study was to determine the relationship between idiopathic osteosclerotic lesions and occlusal forces using the T-Scan II computerized occlusal analysis device, and to test the sensitivity of the system in occlusal analysis. METHOD AND MATERIALS: The study was conducted with 21 volunteers with idiopathic osteosclerosis (IO; 14 women, 7 men) aged between 17 and 62 years (mean 29.95). For every patient, seven or eight recordings were made with the T-Scan II occlusal analysis device in maximum intercuspation, and the last two (excluding any with technical problems) were chosen for evaluation. For each lesion-related area, the distribution of high occlusal forces from two different movies was analyzed. RESULTS: In 18 patients (85.71%), lesions were observed in an area of high occlusal force, and in 13 patients (61.9%), the lesions were located at the first area subjected to high occlusal forces. The percentage distribution of high forces at a lesion related area ranged from 0% to 88%. On average, the high forces at an osteosclerotic lesion area accounted for 20% of the maximum total force. No statistical differences were observed between the measurements of the two selected recordings (P > .05). CONCLUSION: The findings of this study suggest a possible relationship between IO and occlusal forces and primary contacts. T-Scan II was found to be a successful diagnostic device for detecting primary contacts and excessive occlusal forces.

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