In order to determine the major cephalometric and gnathometric features in children with undifferentiated connective tissue dysplasia, a comprehensive clinical-instrumental and X-ray examination was carried out involving 109 children aged 11-16 and featuring a set of signs pointing at connective tissue failure. Depending on the severity of the external phenotypic manifestations as well as clinical and instrumental signs, the patients were divided into groups with mild, moderate and severe undifferentiated dysplasia. The gnathometric and biometric maxillofacial studies were performed employing traditional methods, while the diagnosis was set following the generally accepted classifications. The head telerentgenograms (lateral projection) interpretation was performed in the Dolphin imaging software. The analysis of the head telerentgenograms (lateral projection) was done through the Schwartz S. method subject to the norm indicators proposed by A.A. Anikienko. The nature and the intensity of morphofunctional issues in the craniofacial structures (small stigmas) were found to be determined by the severity of dysplastic connective tissue disorders. Constitutional and morphological dysgenesia, as a manifestation of connective tissue dysplasia, is the reason behind abnormal development in the anatomical structure of the cranial and facial regions. It is displayed through increasing dolichocephaly with a decrease in the face width and vertical size, poorly developed jaws, distal displacement of the mandible in relation to the skull base combined with a deep incisal overbite, increased sagittal interincisal distance, and the vertical type of jaw growth. Thus, the pathogenetic mechanisms facilitate the development of malocclusions. K E y w o r d s -children, adolescents, undifferentiated connective tissue dysplasia, facial skeleton, cephalometry, gnathometry, maxillofacial region, lateral projection of head telerentgenogram.

BiometriC aPProaCH to diaGnosis and manaGement oF morPHoloGiCal CHanGes in tHe dental struCture a b s t r a C t-Clinical examinations, biometric studies of jaw diagnostic models and cone-beam computed tomography were performed involving 104 people in their first adult period with a full set of permanent teeth, the physiological occlusion and the mesognathic type of dental arches. Clinical and X-ray-morphometric explanation of the proportional parameters of the dental and alveolar triangles, taking into account the medial incisors individual position, allowed us developing, substantiating and testing a biometric diagnostic approach to treat morphological changes in the dental structure. Patients, depending on the interincisal angle, featured the mesotrusion type (interincisal angle, 130°-140°), the protrusion type (interincisal angle below 129°) and the retrusion type of the dental arches (interincisal angle above 141°). The study revealed that the distance between the central points of the dental and alveolar triangles on both jaws could be described with the trusion type of arches. The smallest distance between the peaks of the dental and alveolar triangles was to be observed in people with the retrusion type of the arches and microdontia (upper jaw, 1.5±0.07 mm; lower jaw, 0.5±0.02 mm); the average value was recorded in patients with the mesotrusion type and normodontia (upper jaw, 2.5±0.06 mm; lower jaw, 1.5±0.05 mm); the maximum distance was observed in people with the protrusion type of the arches and macrodontia (upper jaw, 3.5±0.08 mm; lower jaw, 2.5±0.07 mm). The morphometric data interpretation can be used to describe the physiological occlusion, when choosing the tactics and the methods of orthodontic treatment for patients with disturbed shape and size of the dental arches, as well as when designing artificial dental arches for patients with full or partial adentia, thus seeking to achieve a balanced articulation balance. K E y w o r d s-biometric diagnostics, dental arches, alveolar arches, microdontia, macrodontia, normodontia, protrusion of incisors, retrusion of incisors, mesotrusion of incisors.

Based on 79 lateral projection head teleroentgenograms obtained from relatively young patients (median age, 37.4±4.3), we have developed a method for the occlusal plane orientation in view of cranio-facial anatomical reference points. As stable anthropometric reference points, we employed the gnathic angle shaped by the spinal and mandibular planes, as well as the interalveolar angle, where the subspinal Downs point and the supramental point were employed as retention elements. When reconstructing the occlusal plane in patients with dentoalveolar anomalies, the construction of the bisector of the interalveolar angle was explained as a key reference point, which allows diagnosing occlusion anomalies in the vertical direction (symmetrical and asymmetric) not only in the lateral, yet also in the frontal segment of the dental arches. The method developed for constructing the occlusal plane does not depend on the position of the incisors and the second permanent molars, which can be used to identify the vertical deformation of the dental arches.

Cone-beam computed tomograms of 68 people (age — 21–35) with physiological occlusion and various gnathic dental arches were analyzed by a method developed for identifying the palatal arch index, taken as a height (depth)-to-width dimension ratio. The results of the study revealed that palatal parameters are determined by main variants (types) of the palatal vault. In case of the mesopalatal type of the arch (index value — 35–45%), the width parameters exceeded the depth values by an average of 2.4 times, while the divergence angle of alveolar processes was 116.7 ± 5.6°. The dolichopalatal type of the arch (index value – above 45%) featured domination of the width parameters over the depth-related ones, by an average of 1.8 times, while the alveolar processes divergence angle made up 127.6 ± 6.1°. As far as the brachypalatal type of the arch is concerned (index value — below 35%), the width parameters exceeded the depth parameters by 4.0 times on average, the divergence angle of the alveolar processes being 113.5 ± 5.3°. The obtained data can be used in clinical orthodontics when diagnosing pathologies of the palatal vault, as well as to interpret data from additional methods of examination and to choose the right treatment for issues related to the dental arch shape and size.

Morphometric data on the structure of the craniofacial complex are reliable and diagnostically significant values that are of applied nature in terms of practical dentistry. Within this study, analysis of conebeam computed tomograms, biometric indicators of plaster models obtained from the jaws of 83 people (aged 21–35) with physiological occlusion and various types of dental, gnathic dental arches, the degree of proportion between the maxillary apical base and the inter-canine distance were identified. Depending on the dental arch type, the patients were divided into three groups. The morphometric study in the CBCT frontal plane was the distance between the canines tearing tubercles and the inter-canine distance in the apical area. The study outcomes revealed discrepancies between the calculated and actual indicators of the apical base width for all types of dental arches in people with physiological occlusion. In case of mesotrusive dental arches (incisional angle — 127–143°), the width of the apical base corresponded to the width of the dental arches between the canines, while the differences in indicators were not statistically significant. In people with retrusive dental arches (incisional angle exceeding 144°), the width of the dental arch was found to be significantly above the width of the apical bases. As far as protrusive dental arches are concerned (incisional angle below 126°), these patients featured predominance of the apical bases width over the inter-canine distance. The obtained data add to that already available in research literature regarding the relationships and dimensional features pertaining to the craniofacial complex structures, as well as have applied value in orthodontic clinical practice