Comparative assessment of the position of teeth and dental arches relative to the LP coordinate parameter in patients aged 18-40 years with distal and mesial occlusion

Aim: to conduct a comparative analysis of anthropometric parameters characterizing the position of teeth and dental arches relative to the LP coordinate parameter in patients aged 18-40 years with distal and mesial occlusion. Material and methods. A retrospective comparative study included 50 patients with distal occlusion (main group 1), 80 patients with mesial occlusion (main group 2), and 50 volunteers with normal occlusion (control group), all aged 18-40 years. The inclusion criterion was the completed period of active facial skeleton growth. Assessment was performed using lateral cephalometric radiographs and digital 3D models of dental arches (STL files) analyzed in the “Ortho-3d.ru” software. Measurements of distances from the LP point to key points of the upper (Mв, 6в, 3в, Iв) and lower (Мн, 6н, 3/4, Iн) dental arches were taken, normalized to the sum of the mesiodistal dimensions of the four upper incisors (Σ4в=31 mm). Results. Oppositely directed vectors of dental arch displacement in the two anomalies were established. In distal occlusion, a significant (p 0.001) mesial displacement of the upper arch (LP-Mв +3.5 mm) and distal displacement of the lower arch (LP-Mн -4.9 mm) were revealed. In mesial occlusion, the opposite pattern was recorded: distal position of the upper arch (LP-Mв -3.1 mm) and mesial position of the lower arch (LP-Mн +8.7 mm). The most pronounced changes in both groups were noted in the anterior segment (parameters LP-Iв, LP-Iн). Refining the age range (18-40 years) minimized the influence of growth factors on parameter variability. Conclusions. The proposed method using the LP coordinate point is highly informative for the differential diagnosis and pathogenetic analysis of distal and mesial occlusion, revealing characteristic and opposite patterns of spatial relationships. Restricting the study to the 18-40 age group ensures data comparability by assessing a fully developed dentofacial system, which is an important condition for standardizing diagnostic criteria in orthodontics.