This article is concerned with peculiarities of points’ placement in orthodontics and study of cephalometric parameters on 3D reconstructions. The aim of the investigation is to develop out the algorithm of distribution of main cephalometric points on 3D reconstructions, received from CBCT and compare characteristics of measurements done on classic teleroentgenogram (TRG) and 3D reconstructions. Materials and methods. The main angular (SNA, SNB, ANB, SN-Ba) skeletal saggital parameters, vertical (ML-NSL, NL-ML, Facial axis, <G), and dental were taken (+1/NL, -1/ML, +1/-1). The analysis of dental radiographs was done for cephalometry «AudaxCeph». Teleroentgenogram and 3 D reconstructions of 20 patients were investigated. Comparing all indices of TRG and 3D reconstructions statistically significant difference was not revealed (р> 0,05). The most significant indices was established during the study of incisive indices - +1/NL, 110±2,72 и 110,2±5,02 correspondingly inter-incisal angle +1/-1 - 133,8±2,21 and 138±5,79.

The growth and development of the facial skeleton is closely related to the growth of the cervical division of the spinal column. With a total increase in rate of osteopenic diseases and diseases of periodontal tissues, computed tomography becomes a particular relevant diagnostic technique for assessing bone density. The aim of this study was to carry out a comparative analysis of the mineral density values of the jaw bone tissue and the mineral density values of the second cervical vertebra in patients with malocclusions. Materials and methods. We analyzed 22 computer tomograms of orthodontic patients and divided all cases into two age groups according to the periods of dentofacial development. The bone density of the second cervical vertebra and jaw bones was measured in various sections. Results. The optical bone density in the second cervical vertebra increases with age from 501±61.06 to 550.6±45.32. The densest area in both jaws is the alveolar ridge between the central incisors. The lowest values of optical density were found in the area of the upper jaw tuberosity in both groups. In the lower jaw, similar results of bone density were found out in the second cervical vertebra and the articular head, 436 HU and 557 HU in the groups I and II, respectively. In both jaws, the most similar densitometric indicators of bone density were found in the second cervical vertebra and the bifurcation site of the first molars. Only in the group II, this figure was 724.77±41.64 HU at p2<0,01 in the lower jaw. Conclusions. Bone tissue densitometry by computed tomography is a highly informative diagnostic technique and can be used to diagnose the condition of the jaw bone tissue and to assess the quality of orthodontic treatment. The value of the second cervical vertebra is a stable indicator of mineral density in all age groups. The results obtained allow us to recommend applying these indicators for the comparative characteristic of change in mineral density in the alveolar processes of jaw bones to check the progress of orthodontic treatment.

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This article describes the assessment of the condition, symmetry of temporomandibular joint and timely diagnosis of its dysfunction based on to H. Gelb method in malocclusion. The objective of this study was to investigate the position and assess the symmetry of the temporomandibular joint heads according to H. Gelb in cases of malocclusion. Materials and мethods. The study was based on analysis of computed tomographs of 70 patients with malocclusion. Depending on the stage of the occlusion development, the patients were divided into two groups: I group included 30 patients with mixed dentition and II group included 40 patients with permanent dentition. Results. The results obtained demonstrated that regardless of the pathology of the occlusion and age, only 8 patients had the correct bite, i.e. the symmetrical position of the temporomandibular joint heads in the Gelb 4/7 position. The most frequent symmetric position of the articular heads in the patients of the I group I was the Gelb ¼ position found in 16 patients; the Gelb 1/5 position was revealed in 8 patients of the II group that can be explained as age-related changes in the displacement of the articular heads from the Gelb 1/4 to 1/5 position. Conclusions. According to the results of our research, it was found that regardless of the malocclusion and age, patients who have the correct position of the temporomandibular joint heads on the left and right in the Gelb 4/7 position make up only 10.52%. The age-related dynamics of the rotational displacement of the centre of the articular heads from the Gelb 1/4 to 1/5 position has been observed, and the number of patients with the asymmetric position of the temporomandibular joint articular heads is increaing.