ABSTRACT
The purpose of the study is improving the effectiveness of rehabilitation of adolescents with a cleft lip and palate based on the orthopedic technologies implementation aimed at replacing the tooth-alveolar defect in the area of the alveolar ridge cleft at the active orthodontic treatment stage. MATERIALS AND METHODS: In the period from 2013 to 2020, 44 patients aged 10 to 18 years with unilateral and bilateral cleft lip and palate were observed. During orthodontic treatment with active appliances all patients received a removable plastic prosthesis with an artificial tooth (or several teeth) in it covering the defect of the alveolar process in the cleft area. An experimental dental alveolar model was made in a 1:1-scale, based on an axial computed tomographic section of the upper jaw, examined in polarized light on the installation with a source of scattered white light with a 1600-2000 cd/m2 brightness to study the distribution of stresses in the dental alveolar complex using an active orthodontic arch. The assessment of chewing efficiency was carried out on the evaluation of the nut (hazelnut) crushing degree. RESULTS: The study of the experimental tooth-alveolar model with a bracket system with an active orthodontic arch with an included defect in the dentition in the area of the cleft of the alveolar process showed an uneven and deviant distribution of stresses in the tooth-alveolar complex, the vector of which depends on the presence or absence of a rigid connection between the alveolar fragments (imitation of the presence or absence of bone regenerate in the cleft). The use of a restorative construction reduces the time when performing a chewing test and increases the efficiency of chewing in patients with unilateral (p=0.02) and bilateral (p=0.008) cleft. It is associated not only with the restoration of the continuity of the dentition with an orthopedic structure, but also with the activation and structuring of the function of the tongue when performing chewing movements. CONCLUSION: The use of a proposed restorative appliance allows: to create the continuity of the upper dentition that harmonizes the distribution of forces from the active orthodontic arch; increases the stability of the teeth in the areas of the upper jaw adjacent to the cleft (incisors and canines) and prevents their unwanted displacement; promotes directional movement of the teeth; in the retention period, to maintain the achieved expansion of the dentition while maintaining space for the future fixed prosthesis; isolate the mouth of the anterior palate; hold the achieved position of the fragments of the upper jaw until bone grafting.
