Evaluation of the effectiveness of combined orthodontic treatment using MARPE in cases of transversal maxillary insufficiency

Justification. Distal occlusion (II class according to Angle) is one of the most common dentofacial anomalies and is often combined with transverse maxillary insufficiency. In adult patients, due to completed growth, the effectiveness of classical orthodontic approaches is limited, which justifies the use of skeletal expansion methods, in particular the MARPE technology — mini-implant-associated rapid palatal expansion. Study objective — to evaluate the effect of MARPE on maxillary transverse dimensions in patients with distal occlusion by analyzing the coefficients of interpremolar and intermolar arch width compliance with Pont’s standard values, compared to traditional orthodontic therapy. Materials and methods. Sixty patients aged 18 to 35 years with a diagnosis of distal occlusion (Angle Class II) were examined. They were divided into two groups of 30 patients each. The control group received treatment using brackets only; the study group underwent preliminary maxillary expansion using MARPE followed by orthodontic correction. Diagnostic evaluation included determining the coefficients of interpremolar and intermolar arch width compliance with Pont’s standard values before and after treatment. Statistical analysis was performed using the nonparametric Wilcoxon and Mann—Whitney tests (p<0.05). Results. After completion of treatment, statistically significant increases in the interpremolar and intermolar arch width correspondence coefficients to the standard values according to the Pohn method were recorded in both groups. In the study group, the intermolar width correspondence coefficient increased from 46.80±2.02 to 70.37±11.17, and the interpremolar width correspondence coefficient increased from 59.20±9.42 to 70.00±4.99. In the control group, the intermolar width correspondence coefficient increased from 41.23±10.54 to 55.80±4.76, and the interpremolar width correspondence coefficient increased from 59.27±5.78 to 93.70±11.54. Despite higher absolute values in the control group, the expansion pattern was more variable, likely due to the predominance of the dentoalveolar component. Conclusion. The use of MARPE allows for significant and stable expansion of the maxilla through skeletal structures, ensuring a more controlled restoration of the transverse parameters of the dental arch. Analysis of the coefficients of correspondence between the interpremolar and intermolar arch widths and the standard values according to the Pont method confirms the effectiveness of this method in treating adult patients with distal occlusion and transverse insufficiency.