MODELING USING REGRESSION ANALYSIS OF INDIVIDUAL LINEAR DIMENSIONS OF PREMOLARS DEPENDING ON CEPHALOMETRIC INDICATORS OF PRACTICALLY HEALTHY MEN FROM DIFFERENT REGIONS OF UKRAINE

Abstract

According to the literature, the development of a variety of diagnostic models should be adapted to the use of specific regions within the range of the settlement of large ethnic groups of the population.

The aim of the study – to construct and analyze the regression models of individual linear sizes of small angular teeth depending on the cephalometric indices of practically healthy men from different administrative-territorial regions of Ukraine.

Materials and Metohods. 200 practically healthy men in the third generation residents of different administrative-territorial regions of Ukraine (northern region – 32 inhabitants from Zhytomyr, Kyiv, Chernihiv and Sumy regions; southern region – 33 inhabitants from Odesa, Mykolaiv, Kherson, Zaporizhzhia regions and the Autonomous Republic of Crimea; central region – 64 inhabitants from Vinnytsia, Cherkasy, Kirovohrad, Poltava and Dnipropetrovsk regions; western region – 36 inhabitants from Volyn, Rivne, Lviv, Chernivtsi, Ternopil, Khmelnytskyi, Transcarpathian and Ivano-Frankivsk regions; eastern region – 35 inhabitants from Kharkiv, Donetsk and Luhansk regions), a computer-tomographic study of small corner teeth with subsequent odontometry and cephalometry was conducted. The construction of regression models of individual linear dimensions of small corner teeth, depending on the cephalometric indices, was performed using the statistical software package "Statistica 6.1".

Results and Discussion. By using regression analysis based on the features of cephalometric indices, craniotype and face type we have built reliable models (with determination coefficient R2 greater than 0.5) of individual linear sizes of small angular teeth of the upper and lower jaws in practically healthy men of the northern (6 models of mesio-distal dimensions, R2 = 0.562–0.715; 4 models of vestibular-lingual dimensions, R2 = 0.525–0.822; 3 models of height of crowns, R2 = 0.507–0.632), southern (1 model mesio-distal sizes, R2 = 0.509; 3 models heights of crowns, R2 = 0.564–0.702), western (4 model mesio-distal sizes, R2 = 0.535–0.659; 1 model height crowns, R2 = 0.522) and eastern (6 models of mesio-distal dimensions, R2 = 0.505–0.641; 2 models of vestibular-lingual sizes, R2 = 0.519 and 0.559; 1 model of crown height, R2 = 0.603) administrative-territorial regions of Ukraine. In most cases, regardless of the region, models of mesio-distal dimensions of the crown and neck of small corner teeth are constructed for the upper jaw, and the height of the crowns – for the mandible. To constructed models of individual linear sizes of small angular teeth of the upper and lower jaws with a determination coefficient more than 0.5 most often include: in men of the northern region of Ukraine to models of mesio-distal dimensions – the transverse arc and the width of the mouth gap (by 10.5 %) and width base of the nose, width of the lower jaw and length of the body of the mandible on the left (by 7.9 %); to models of vestibular-lingual dimensions – the height of the upper part of the face (16.0 %), the largest length of the head, the length of the body of the mandible on the left and the morphological length of the face (by 12.0 %); to models of crown height – foreign eye width (18.7 %) and transverse arc and length of the body of the mandible on the left (by 12.5 %); in men in the southern region of Ukraine to models of crown height – height of the forehead (17.6 %), the largest girth of the head, the width of the base of the nose, the intercostal width and the length of the body of the mandible on the right (by 11.8 %); in men of the western region of Ukraine to models of mesio-distal sizes – the largest head circumference and the distance between the nasion and the inter-cutter point (by 14.8 %), the transverse arc, the width of the mouth gap and the length of the body of the mandible on the right (by 11.1 %); in men of the eastern region of Ukraine to models of mesio-distal dimensions – sagittal arc, mouth width and forehead height (by 12.8 %), mean facial width (10.3 %) and body length of the mandible on the left (7.7 %); to the models of vestibular-lingual dimensions – the transverse arc, the width of the mouth, the width of the mandible, and the length of the nose (by 14.3 %).

Conclusions. Based on the features of cephalometric indices and the type of head and face in practically healthy men from different administrative-territorial regions of Ukraine, reliable regression models (with determination coefficient R2 greater than 0.5) of individual linear sizes of small angular teeth of the upper and lower jaws have been developed.