Condylar volume and surface in Caucasian young adult subjects

<p>Abstract</p> <p>Background</p> <p>There have been no quantitative standards for volumetric and surface measurements of the mandibular condyle in Caucasian population. However, the recently developed cone-beam computed tomography (CBCT) system allows measurement of these parameters with high accuracy.</p> <p>Methods</p> <p>CBCT was used to measure the condylar volume, surface and the volume to surface ratio, called the Morphometric Index (MI), of 300 temporo-mandibular joints (TMJ) in 150 Caucasian young adult subjects, with varied malocclusions, without pain or dysfunction of TMJs.</p> <p>Results</p> <p>The condylar volume was 691.26 ± 54.52 mm³in males and 669.65 ± 58.80 mm³in, and was significantly higher (<it>p</it>< 0.001) in the males. The same was observed for the condylar surface, although without statistical significance (406.02 ± 55.22 mm²in males and 394.77 ± 60.73 mm²in females).</p> <p>Furthermore, the condylar volume (693.61 ± 62.82 mm³) in the right TMJ was significantly higher than in the left (666.99 ± 48.67 mm³, <it>p </it>< 0.001) as was the condylar surface (411.24 ± 57.99 mm²in the right TMJ and 389.41 ± 56.63 mm²in the left TMJ; <it>t </it>= 3.29; <it>p </it>< 0.01). The MI is 1.72 ± 0.17 for the whole sample, with no significant difference between males and females or the right and left sides.</p> <p>Conclusion</p> <p>These data from temporomandibular joints of patients without pain or clinical dysfunction might serve as examples of normal TMJ's in the general population not seeking orthodontic care.</p

The Effect of Migration on Latvia’s Sex and Age Composition

The theory of Demographic Transition stipulates that the number of countries with the replacement and sub-replacement level of the total fertility rate is growing. In these conditions, population dynamics and the sex and age composition are increasingly affected by migration. The above holds true for Eastern European countries. Population decline has haunted Latvia for two and a half decades. Since 1990, the net migration rate has been negative, which contributes to depopulation. This study aims to reveal the effect of migration on the sex and age composition across Latvia and its largest cities. The authors consider hypothetical transformations in the country’s age structure in 2000—2015 in the case of zero net migration. The study uses the cohort component methods and considers the actual agespecific mortality and birth rates. The analysis of the results obtained for the population of Latvia and its individual cities makes it possible to identify temporal and age/space features of migration. A comparison of the official data with net migration rates calculated for different age groups ensures a more accurate estimate of the actual volume and direction of migration flows for certain Latvian cities. The method for calculating net migration for the selected age groups, described in the article, may narrow the gaps in the current migration statistics and reveal the territorial inhomogeneity of demographic processes