Integral criteria for determining indications for surgical repositioning of the premaxilla in patients with bilateral cleft lip and palate at the stage of alveolar bone grafting

Objective. To substantiate the criteria for surgical repositioning of the premaxilla in patients with bilateral cleft lip and palate at the stage of preparation for alveolar bone grafting based on a comprehensive assessment of clinical and morphometric data. Materials and Methods. The study included 42 patients (mean age 10.9 years) with bilateral cleft lip and palate who had previously undergone primary surgical repair. At the initial stage, the spatial position of the premaxilla was assessed according to four parameters: protrusion, vertical dystopia, rotation, and deviation. All patients underwent orthodontic treatment aimed at preparing for alveolar bone grafting. In cases of ineffective orthodontic correction, surgical repositioning of the premaxilla was performed. According to treatment outcomes, the patients were divided into two groups: 16 patients (38.1%) who required surgical repositioning and 26 patients (61.9%) in whom the deformity was successfully corrected orthodontically. Morphometric measurements were performed using multislice computed tomography (MSCT) of the skull and plaster dental models. Results. In the group of patients who underwent surgical repositioning, the median values were: protrusion — 10.3 mm (5.0—16.6), vertical dystopia — 10.4 mm (2.5—15.2), rotation — 13.0° (0.0—57.0), and deviation — 2.0 mm (0.0—8.6). In the group with successful orthodontic correction, the parameters were lower: protrusion — 4.4 mm (1.6—9.1), vertical dystopia — 2.6 mm (0.0—11.5), rotation — 10.0° (0.0—34.0), and deviation — 1.6 mm (0.0—5.9). Statistically significant differences were found for protrusion and vertical dystopia (p<0.0001). Based on the threshold values of the studied parameters, three clinical zones were identified: effective orthodontic correction, a borderline zone, and a zone of pronounced deformity. To objectify treatment indications, an integral deformity index of the premaxilla was developed. It was established that surgical repositioning is not required when the index value is ≤1.168, whereas values ≥1.622 indicate a justified need for surgical intervention. Conclusion. A comprehensive assessment of deformity parameters made it possible to develop a three-zone clinical decision model and an integral deformity index that allows objective determination of indications for surgical repositioning of the premaxilla.