Regression models of computed tomographic dimensions necessary for building the correct shape of the dental arch in Ukrainian young men and young women with a physiological bite

Orthodontics plays a crucial role in ensuring facial aesthetic harmony and functional correctness of the dentoalveolar system. Cephalometric analysis is an essential tool in orthodontic treatment planning, as its parameters vary significantly depending on the patient's age, sex, and nationality. Understanding these differences is critically important for accurate diagnosis and effective treatment across different populations. The aim of the study is to construct and analyze regression models of computed tomography dimensions necessary for constructing the correct shape of the dental arch in Ukrainian young men and young women with a physiological bite, depending on the specific cephalometric parameters according to the Ricketts method and computed tomography tooth dimensions. In the licensed software OnyxCeph³™ version 3DPro, primary computed tomography scans of Ukrainian young men (n=41) and young women (n=68) with physiological bites were analyzed, obtained from the database of the Department of Pediatric Dentistry and the Research Center of the National Pirogov Memorial Medical University, Vinnytsya. According to the Ricketts method, "dental," "skeletal and dentoskeletal," "soft tissue aesthetics," "craniofacial relationships," and "internal structures" indicators were determined on lateral cephalograms. Morphometric parameters of upper and lower jaw teeth were determined in the mesiodistal and buccolingual directions on computed tomography scans, as well as distances necessary for constructing correct dental arch forms. Regression models of the linear dimensions necessary for constructing the correct dental arch shape, depending on the specific cephalometric parameters according to the Ricketts method and computed tomography tooth dimensions, were constructed using the licensed "Statistica 6.0" package. It was found that in Ukrainian young men, all 18 possible reliable regression models were constructed with a coefficient of determination greater than 0.6 (R²= from 0.617 to 0.833, p<0.001 in all cases); while in Ukrainian young women, only 6 reliable regression models were constructed with a coefficient of determination greater than 0.6 (R²= from 0.605 to 0.793, p<0.001 in all cases). When analyzing the percentage of inclusion in the regression equations of cephalometric parameters and computed tomography tooth dimensions, it was found that in Ukrainian young men, cephalometric parameters and crown width in the mesiodistal direction were most frequently included in the models (26.67 % each), distance from the incisal edge to the apex of the tooth root (13.33 %), and crown width in the buccolingual direction (10.00 %); while in Ukrainian young women, cephalometric parameters and crown width in the mesiodistal direction were most frequently included in the models (21.95 % each), crown width in the buccolingual direction (14.63 %), and distance from the incisal edge to the apex of the tooth root (9.76 %). When analyzing the percentage of inclusion in the regression equations of respective teeth, it was found that in Ukrainian young men, upper incisors were most frequently included in the models (20.00 % – 8.33 % central incisors and 11.67 % lateral incisors), lower incisors (13.33 % – 4.17 % central incisors and 9.17 % lateral incisors), upper canines (10.83 %), and upper premolars (10.00 % – 2.50 % first premolars and 7.50 % second premolars); while in Ukrainian young women, upper incisors were most frequently included in the models (29.27 % – 21.95 % central incisors and 7.32 % lateral incisors) and lower premolars (12.20 % – 4.88 % first premolars and 7.32 % second premolars). Thus, in Ukrainian young men and young women with a physiological bite, highly informative reliable regression models of linear dimensions necessary for constructing the correct dental arch shape, depending on the specific cephalometric parameters according to the Ricketts method and computed tomography tooth dimensions, were constructed using regression analysis.