Selmi Yilmaz

The effect of 3 T MRI on microleakage of amalgam restorations

OBJECTIVES To evaluate the effects of 3 T magnetic field on microleakage of amalgam restorations containing three different types of silver (Ag). METHODS 60 extracted teeth were restored with three different types of amalgam filling materials. Restored teeth were sectioned mesiodistally and divided into experimental and control groups. Experimental groups were exposed to a magnetic field of 3 T for 20 min. All samples were plunged into 2% basic fuchsin solution and examined under a digital microscope by three different observers with regard to microleakage. RESULTS Statistical analysis showed significant differences in microleakage between the groups exposed to MRI and controls, whereas differences in microleakage between amalgam types were insignificant. CONCLUSIONS The primary risk of MRI systems arises from the effects of its strong magnetic field on objects containing ferromagnetic materials. An MRI of 1.5 T is known to be safe for amalgam restorations. However, our research indicates that MRI is not completely devoid of any effects on amalgam restorations.

Age estimation using maxillary canine pulp/tooth area ratio, with an application of Kvaal’s methods on digital orthopantomographs in a Turkish sample

The present study was designed to test the applicability of Kvaal’s method on digital orthopantomographs and to develop a new formula measuring pulp/tooth area ratio from periapical X-rays in a group of individuals living in Central Anatolia. Orthopantomographs and periapical X-rays of 114 patients aged between 17–72 years were selected. According to reported technique, three mandibular teeth were evaluated in each orthopantomogram with Kvaal’s method. Additionally, the pulp/tooth area ratio was measured on periapical X-rays of maxillary canine. Correlations between real age and morphological variables were calculated for all teeth using Pearson’s correlation coefficient. Kvaal’s method on digital panoramic radiographs gave acceptable results (standard deviation, SD = 5.9 to 7.9 years) that were close to the original. In addition, regression equations were developed to estimate age from morphological variables and the best results were achieved using the regression equation for the maxillary canine with a pulp/tooth area ratio (standard error of estimate, SEE = ±6.75; coefficient of determination R2 = 0.67). There was no significant difference between observed and estimated age for age groups and gender based on the established regression equations. With this particular study group, the equations presented in the study gave more accurate results than Kvaal’s original equations and may be considered more suitable for a Turkish population.

A Diagnosis of Maxillary Sinus Fracture with Cone-Beam CT: Case Report and Literature Review.

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.

Diagnosis of acute myeloid leukemia in a dental hospital; report of a case with severe gingival hypertrophy

Acute myeloid leukemias (AMLs) are aggressive hematopoietic neoplasms that, if untreated, can lead to death within days. Owing to its high morbidity rate, early diagnosis and appropriate medical therapy is essential. Oral lesions may be the presenting feature of acute leukemias and are, therefore, important diagnostic indicators of the disease. Erythematous or cyanotic gingival hyperplasia with or without necrosis is reported to be the most consistent symptom leading to a diagnosis of acute leukemia that directs the patient to seek early dental consultation. This report refers to a patient with AML that was provisionally diagnosed in the dental hospital due to severe gingival enlargements.

A possible association of idiopathic osteosclerosis with excessive occlusal forces.

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.

The evaluation of idiopathic osteosclerosis on panoramic radiographs with an investigation of lesion's relationship with mandibular canal by using cross-sectional cone-beam computed tomography images

Objective: The aim of this study was to determine the prevalence of idiopathic osteosclerosis (IO) in a Turkish population on orthopantomographs with respect to age, sex, and lesion characteristics and investigate the lesions relationship with mandibular canal with the aid of cross-sectional cone-beam computed tomography (CBCT) images. Materials and Methods: 8000 panoramic radiographs taken with two digital orthopantomograph devices over a 10-month period were evaluated. Each patient was assigned an identification number, and demographic information (age, sex), absence/presence of a lesion, and if present, lesion characteristics (localization, dental relationship, size, and shape) were recorded. Additionally, cross-sectional CBCT images of 30 patients with IO were examined in terms of relationship with mandibular canal. Results: 273 IO lesions were detected in 225 patients (130 females, 95 males; mean age: 33.1 years). The majority of lesions were observed in the mandibular premolar and molar areas. IO lesions occurred more frequently among middle-aged individuals and at higher rates among females (3.1%, n = 130) than males (2.8%, n = 95); however, differences by age and sex were not statistically significant (P > 0.05). Cross-sectional images revealed that 80% of the lesions were in contact with mandibular canal. None of the lesions showed any cortical expansion. Conclusions: This large-scale study found IO to have a low prevalence rate among a Turkish population. IO was observed to occur more frequently in females than in males and to be most common among individuals aged 20-29. CBCT results suggested a possible association between IO lesions and mandibular canal.

Ex Vivo Mercury Release from Dental Amalgam after 7.0-T and 1.5-T MRI

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.

Evaluation of volumetric measurements on CBCT images using stafne bone cavities as an example.

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. Key words:Stafne bone cavity, CBCT, volumetric measurements, image segmentation.

Assessment of Third Molar Impaction Pattern and Associated Clinical Symptoms in a Central Anatolian Turkish Population.

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.

To see bruxism: a functional MRI study

OBJECTIVE Since the pathophysiology of bruxism is not clearly understood, there exists no possible treatment. The aim of this study is to investigate the cerebral activation differences between healthy subjects and patients with bruxism on behalf of possible aetiological factors. METHODS 12 healthy subjects and 12 patients with bruxism, a total of 24 right-handed female subjects (aged 20-27 years) were examined using functional MRI during tooth-clenching and resting tasks. Imaging was performed with 3.0-T MRI scanner with a 32-channel head coil. Differences in regional brain activity between patients with bruxism and healthy subjects (control group) were observed with BrainVoyager QX 2.8 (Brain Innovation, Maastricht, Netherlands) statistical data analysis program. Activation maps were created using the general linear model: single study and multistudy multisubject for statistical group analysis. This protocol was approved by the ethics committee of medical faculty of Kirikkale University, Turkey (02/04), based on the guidelines set forth in the Declaration of Helsinki. RESULTS The group analysis revealed a statistically significant increase in blood oxygenation level-dependent signal of three clusters in the control group (p<0.005), which may indicate brain regions related with somatognosis, repetitive passive motion, proprioception and tactile perception. These areas coincide with Brodmann areas 7, 31, 39 and 40. It is conceivable that there are differences between healthy subjects and patients with bruxism. CONCLUSIONS Our findings indicate that there was a decrease of cortical activation pattern in patients with bruxism in clenching tasks. This indicates decreased blood flow and activation in regional neuronal activity. Bruxism, as an oral motor disorder concerns dentistry, neurology and psychiatry. These results might improve the understanding and physiological handling of sleep bruxism.