[en] Geophysicists contribute their knowledge to the solution of many societal problems-seismic and volcanic risk, exploration and mapping to name a few. A field of special demand which has recently grown important is nuclear waste disposal. This article summarizes the background of nuclear waste disposal problem and how geophysicists are contributing to its solution and what kind of geophysical techniques are used to solve the nuclear waste disposal problem

[en] Magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ) and temporomandibular disorders (TMDs) have been discussed in detail for various populations. As no such study has examined the Turkish population, we determined the frequency of TMDs in the Turkish population through a multicentric investigation using MRI. This retrospective study examined 504 TMJs of 252 symptomatic patients who had undergone bilateral MRI investigation in four different dental schools. The image analysis included the assessment of disc position and morphology, and recaptured the coronal and sagittal planes in the closed and open mouth positions. The TMJ disorders were classified using the Clinical Diagnostic Criteria for Temporomandibular Disorders (CDC/TMD). The correlations among the groups of TMJs and disc morphologies were analyzed statistically using the chi-square test (P≤0.05). Disc displacement and abnormal disc morphology were detected in 69.5% of the symptomatic TMJ patients. Of the joints examined using MRI, 154 were normal, 135 had anterior disc displacement with reduction (ADDwR), 145 had anterior disc displacement without reduction (ADDwoR), 30 had partial anterior disc displacement, and 18 had sideways disc displacements. Regarding disc morphology, enlargement in the posterior band was the most commonly encountered type and was observed in 152 TMJs. Overall, the average time for referral for treatment, which was defined as the time from symptom onset until the time of referral, was 1.5 years. The most common type of disc displacement found in the Turkish population studied was ADDwoR. In addition, patients did not perceive the symptoms of TMDs as a disease and did not seek help until the TMJ derangement caused a major complaint. (author)

[en] The aim of this study is to evaluate the correlation between constitutional delayed growth (CDG) and mandibular bone trabeculation as well as bone density on panoramic radiographs using a computer software program. Panoramic radiographs obtained from 25 patients with CDG and 25 healthy adolescents were evaluated for this study. Patients were selected from admission to Hacettepe University, Faculty of Medicine, Section of Adolescent Medicine in the first half of the year 2002. All panoramic radiographs were taken under standard conditions, and were randomized and then converted to digital images for density analysis using a scanner. The images were transferred to Osiris computer software program for the evaluation of bone density from 4 different regions on the mandible (right and left mandibular angle and condyle). The CDG group had higher values for the risk of osteoporosis considering the right (t=3.360, p=0.002) and the left condyle (t=3.620, p=0.001) (t-test for independent samples). It was also seen that the CDG group was again at higher risk in comparison to the control group when left mandibular angle values were measured (z= -2.447, p=0.014) (Mann Whitney - U test). We suggest that panoramic radiographs, which are transformed into digital format, can be valuable and economic tools for detecting the risk of osteoporosis in adolescents with CDG. (author)