MODERN APPROACHES TO THE DETERMINATION OF THE ANGLE OF TEETH INCLINATION IN THE DIAGNOSIS AND PLANNING OF ORTHODONTIC TREATMENT

Abstract

Aim. To conduct a comparative analysis of existing methods for measuring the angles of inclination of tooth and determining the torque of teeth with orthognathic occlusion.Materials and methods. Inclination angles were measured in 137 patients with physiological occlusion and the standard values of the torques of permanent teeth. Four methods of investigation were used to measure tooth torques. In the first method, the angle of the inclination formed by the occlusal plane and the conditional middle vertical of the tooth was measured by the protractor on the incisions of the plaster models of the dentition rows. The second method, which allows evaluating torques and teeth angulation at the same time, was carried out with the aid of the «Arco-zet» apparatus of «Scheu Dental GmbH». As the third method of research, the technique of analyzing images of cone-beam computed tomography was used, on which linear and angular reference points were applied. The fourth method of investigation was based on the results of scanning gypsum models with a laser scanner "ORAPIX" with the subsequent creation of a digital three-dimensional image and the formation of a virtual Set-Up model in the file "ORAPIX" 3Txer 2.5.0.Results. All methods of measuring the angles of teeth in the vestibular-lingual direction can be applied both in the applied and in the clinical aspect. Determining the torques of permanent teeth using the morphometry of gypsum models of dentition and instrumentation method is characterized by laboriousness, length of studies, and also the presence of errors in measurements. Methods for analyzing images of cone-beam computed tomography and using the virtual diagnostic SetUp model in the ORAPIX file 3Txer 2.5.0 are high-tech, precise, and reproducibility and interpretation of the results allows using the available angular and linear parameters for assessing the effectiveness of conducted orthodontic activities at all stages of treatment.Conclusion. The introduction into clinical orthodontics derived from research boundaries reference values and confidence intervals inclination angles of the upper teeth, the lower jaw, as well as tilt incline of teeth of antagonists will reduce the time required for the early stage diagnosis and increase the effectiveness of the test results of orthodontic treatment. Improvement of existing methods of diagnosis of dentoalveolar anomalies has led to the creation of high-tech, precision, computerized measurement methods, the introduction of which will allow not only minimizing errors associated with instrumental measurement techniques in the structures of the maxillofacial region, but, due to the predictability of orthodontic treatment, achieving optimal functional – aesthetic results.

Keywords

• a torque of teeth
• an angle of inclination
• cone-beam computed tomography
• virtual diagnostic set-upmodel