Krymovskyy K. Features of orthodontic treatment of patients with different facial skeleton growth patterns in mixed dentition period of occlusion with anterior dental crowding

The thesis presents a theoretical generalization and new solutions to the urgent scientific and practical task of modern dentistry, which is to increase the effectiveness of diagnostic algorithms for patients in mixed dentition with dental crowding in the anterior region and their influence on the choice of treatment methods by developing a diagnostic algorithm and improving appliance treatment. The purpose of the dissertation is to improve the effectiveness of orthodontic treatment of patients with different types of facial skeleton growth patterns during mixed dentition period with dental crowding in the frontal region by substantiating diagnostic and therapeutic measures based on the study of radiographic criteria for jaw growth, functional changes in the width of the airway, and by usage of the author's design of the orthodontic appliance. To achieve this goal, the study was conducted in compliance with the principles of bioethics and evidence-based medicine in accordance with the principles of good clinical practice and especially with the requirements of confidentiality. The study design was approved by the Commission on Bioethical Review and Research Ethics at the Bogomolets National Medical University. Objectives of the study: 1.To study the etiologic factors of crowded teeth in the frontal region in patients with different types of cranial growth. 2.To determine the most characteristic changes in anthropometric parameters in transverse anomalies before and as a result of orthodontic treatment of patients in the variable period of occlusion with different types of cranial growth. 3.To develop an orthodontic appliance for maxillary expansion and to conduct a comparative evaluation of its effectiveness with existing ones. 4.To improve the method of diagnosis and control of treatment of narrowing of maxilla and mandible in mixed dentition period of occlusion with different facial skeleton growth patterns. 5.To develop an algorithm for the treatment of crowded position of the frontal group of teeth using the author's orthodontic appliance. Object of study: indicators of narrowing of the maxilla and mandible on cone-beam computed tomography and anthropometric indicators of narrowing of the dental and basal arches of jaws depending on the facial skeleton growth pattern, bioelectrical indicators of masticatory and facial muscles, clinical varieties of the results of maxillary expansion and expansion of the mandibular dentition, depending on the growth pattern of the facial skeleton and the design of the orthodontic appliance. Development of an algorithm for the anterior dental crowding treatment using the author's orthodontic appliance. Methods of study: general clinical - anamnesis, examination of the oral cavity, palpation of masticatory and facial muscles, photographic protocol; radiological - cone beam computed tomography of the facial skeleton, 3D cephalograms and orthopantomograms synthesized from it; anthropometric - determination of the width of the basal and dental arches of maxilla and mandible by Andrew's Element III analysis, assessment of dental crowding severity by the amount of incisor displacement according to the Little’s Irregularity Index, assessment of space deficiency by the Tanaka-Johnston analysis and Nance longitudinal analysis; instrumental - electromyography of masticatory and facial muscles; statistical - determination of the study validity. Among all 237 examined, we selected 108 children whose parents agreed to the study and who met the inclusion criteria, namely: age from 7 to 11 years, the presence of Engle class I malocclusion and dental crowding in the anterior region, the presence of the first permanent molars before treatment, the absence of congenital anomalies of the dentition and severe generalized somatic diseases. Depending on the pattern of facial skeleton growth, all patients were divided into 3 clinical groups: Study group I - 32 patients (29.6%) with a vertical growth pattern; study group II - 58 patients (53.7%) with a neutral growth pattern; study group III - 18 patients (16.7%) with a horizontal growth pattern. For a detailed study of the etiological factors of dental crowding, we analyzed 127 medical records of children aged from 7 to 11 years at the Department of Orthodontics and Propaedeutics of Prosthetic Dentistry of Bogomolets National Medical University for 2019-2023, and we also took 108 patients for treatment who applied to the Department of Orthodontics and Propaedeutics of Prosthetic Dentistry of Bogomolets National Medical University.