Features of correlations of computer-tomographic sizes of premolars with cephalometric indices of practically healthy men from the western and eastern regions of Ukraine

Abstract

According to the data of modern scientific literature in order to achieve goodfunctional and aesthetic indicators, prevention of the development of relapse in theprocess of orthodontic treatment should take into account the interdependenceodometometric and cephalometric indicators. In this case, orthodontists need to makean amendment to the features of correlations characteristic of one or another ethnicgroup of the population. The purpose of this study was to establish the features of theconnections of linear computational-tomographic sizes of premolars and their roots withcephalometric indices of practically healthy men of the Western and Eastern regions ofUkraine. On the basis of the medical center "Vinintermed LTD", 71 healthy and healthymen aged from 19 to 35 years from the Western region (n = 36, residents from Volyn,Rivne, Lviv, Chernivtsi, Ternopil, Khmelnytsky, Transcarpathian and Ivano-Frankivskregions) and the Eastern region (n = 35, residents from Kharkiv, Donetsk and Luhanskregions), a cone-ray computer tomography was performed using the Veraviewepocs-3D dental cavity beam (Morita, Japan). On cone-ray computer tomograms small angularteeth of the upper and lower jaws were measured: the length of the tooth; the lengthof palatal and cheek's roots of small angular teeth of the upper and lower jaw; heightof tooth crown; vestibular-lingual dimensions of the crown and neck of the tooth;mesio-distal dimensions of the crown and neck of the tooth. Cephalometric studieswere conducted taking into account the generally accepted recommendations andanatomical points. The statistical processing of the obtained results was carried outusing the statistical software package "Statistica 6.1" using the nonparametric Spirmanmethod. A number of anthropogenetic studies confirmed the division of Ukrainians intoregional groups (East, West, North, South), divergence between them reaches a highlevel. Therefore, the difference between the correlations of odonto-kefalometricindices between regions with a larger taxonomic distance (east-west, north-south)should be expected. As a result of the conducted researches in practically healthymen the following regional features of connections of linear sizes of premolars withcephalometric indicators of a brain skull are established: the Western region is mainlydirect reliable (r = 0.34 - 0.45) and unreliable average force (r = 0.30 - 0.36) connections(9.0% on the upper jaw, of which the relative majority are with the height of teeth andtheir crowns and the length of the roots and 7.6% on the lower jaw, of which the relativemajority is mesio-distal and vestibular-lingual sizes); the Eastern region - mostly reversereliable (r = -0.34 - 0.45) and unreliable mean strength (r = -0.30 - 0.34) connections(5.1% on the upper jaw and 5.4% on the lower jaw, in both cases the relative majoritywith the height of the teeth and their crowns and the length of the roots). The followingregional peculiarities of connections were established with the indicators of the facialskull: the Western region - mostly direct (r = 0.33 - 0.57) and unreliable meanstrength (r = 0.30 - 0.42) connections (9.9% on the upper jaw and 12.2% on the lowerjaw, in both cases the relative majority of mesio-distal and horse-lingual dimensions);Eastern region - mostly direct (r = 0.34 - 0.52) and unreliable mean strength (r = 0.30 - 0.44) connections (7.4% on the upper jaw, of which the relative majority with heightteeth and their crowns and the length of the roots and 9.2% on the lower jaw, of whichthe relative majority are mesio-distal and vestibular-lingual dimensions).Keywords: regional features, premolars, cephalometry, correlations, practically healthymen