Regression models of teleroentgenograhic indicators of the position of teeth and the profile of face soft tissues in juvenile aged persons with different face types according to Schwarz A.M.

Abstract

Considering the differences in the values of teleroentgenograhic (TRG) indicators in different racial, gender, ethnic, age, population, geographical population groups and numerical methods of TRG analysis, determination of normative values of cephalometric, gnatometric TRG-indicators, their interdependencies in the population of different countries is extremely important both for human anatomy and for the practice of dentists. This fully applies to residents of Ukraine of different age groups. The aim of the work is to develop and analyze regression models of teleroentgenograhic indicators of tooth position and facial soft tissue profile according to Schwarz A.M. in Ukrainian young men and young women with different facial types. Lateral teleroentgenograms of 49 young men (aged 17 to 21 years) and 76 young women (aged 16 to 20 years) with physiological occlusion as close as possible to orthognathic were analyzed. In the license package “Statistica 6.0” regression models of indicators of position of teeth and profile of soft tissues of the face according to the method of Schwarz A.M. depending on basic cephalometric and gnatometric indicators separately for boys and for girls with different types of the face are constructed. In young men, 16 of the 24 possible reliable regression models were constructed, in which the coefficient of determination is greater than 0.6 (R2=from 0.609 to 0.998). For young men with 1st (back face type) and 3rd (front face type) face types, the following models were created with respect to 5 indicators from 8 possible (respectively, angles Max1-SpP S-arz, distances Sn-Pn and Pog’-Por, angles Gl’LsPog’ and SnPog’-Pn; R2 = from 0.609 to 0.998 and angles Max1-SpP S-arz and Mand1-MP Schwars, distances Sn-Pn and Pog’-Por, angle Gl’LsPog’; R2 = from 0.609 to 0.946), and for young men with 2nd face types (average face type according to Schwarz AM) – for 6 indicators (angles Max1-SpP S-arz and Mand1-MP Schwars, distances Sn-Pn and Pog’-Por, angles Gl’LsPog’and SnPog’-Pn; R2 = from 0.690 to 0.990). In young women, 17 of the 24 possible reliable models with R2 greater than 0.6 (R2 = 0.628 to 0.958) were constructed. For young women with 1st type of face 6 indicators are modeled – angles Max1-SpP S-arz, distances Sn-Pn and Pog’-Por, angles Gl’LsPog’and SnPog’-Pn, the distance of Li-SnPog’(R2= from 0.663 to 0.958). For young women with 2nd face type, the following models were created for 7 indicators – angles Max1-SpP S-arz and Mand1-MP Schwars, distances Sn-Pn and Pog’-Por, angles Gl’LsPog’ and SnPog’-Pn, distances Li-SnPog’(R2= from 0.628 to 0.891). For young women with 3rd face type the smallest number of models with R2 larger than 0.6 was built, compared to all groups of persons with different face types – only 4 models for Max1-SpP S-arz angle, Pog’-Por distance, angles Gl’LsPog’ and SnPog’-Pn (R2 from 0.718 to 0.847).