The study of the influence of removing complete teeth on the face aesthetics in the process of orthodontic treatment of distal occlusion

In the special literature, there are little data on the biomechanics of the dentoalveolar region. Orthodontists meet difficulties in controlling the formation of the occlusion during deformation of the jaws, due to the structural features of their structure. It is also difficult to control the change in the ratio of the jaws and occlusion in three directions in the process of orthodontic treatment, since an increase in the occlusion at rotation of the jaws can negatively affect the aesthetics of the face. The paper presents the direct results of treatment of distal occlusion of teeth with the use of fixed orthodontic technique in 53 patients aged 11-20.5 years, changes in the jaws, bone and soft tissue parameters in order to identify the negative consequences of removing complete teeth on the aesthetics of the face. It is established that the dental arches, apical bases and jaws in the younger and older age change the shape in the process of orthodontic treatment according to the principle of deformation of the elastic body: the dental arches in the premolar and apical bases are widened, their frontal areas are shortened more in patients after tooth removing. In growing patients, the length of the base of the mandible increases. The length of the base of the maxilla, the dimensions of the distances of the jaws, especially after removing of the teeth decrease. The frontal part of the maxilla is displaced posteriorly. Conditions are created to reduce the occlusion height in patients without removing of teeth and to increase occlusion in patients after removing of the two upper premolars. After the extraction of the teeth, there is a tendency to aggravation of facial features due to an increase in nasolabial and nasal convexity. External changes are almost not noticeable at elimination of the main symptom. In addition, quantitative changes in angles occur within the physiological range. The tendency to increase the occlusion with the removing of teeth positively affects the aesthetics of the face: the lips are closed freely, due to the increase of the chin and inter-lip angles, the sub-chin groove becomes less deep. When comparing parameters after treatment with the removing of teeth, more pronounced changes occurred in the mandible parameters: all sizes of the maxilla are statistically significantly less. The majority of bone and soft tissue parameters in the end of treatment became similar in size, irrespective of tooth extraction and did not have a statistically significant difference. The lack of growth of the base of the mandible in patients with a permanent occlusion is a contraindication to the removing of teeth in the distal occlusion caused by underdevelopment of the mandible. The listed questions need of biomechanical research.