Introduction. Connective tissue dysplasia (СTD) is a group of polymorphic pathological conditions caused by hereditary or congenital defects in collagen synthesis and accompanied by a violation of the functions of the musculoskeletal system and internal organs, which is considered as a factor in the development of pathology of the maxillofacial region in children: dystrophic forms of periodontal diseases; anomalies of shape, size, teething; pathology of the temporomandibularthe mandibular joint. There are diffi culties in determining the pathogenetic relationship between CTD and individual nosological forms of dental diseases, which is important for determining the prognosis of their course and the choice of methods of rehabilitation of children. It is important to improve the methodology of preventive examinations in relation to the early detection of phenotypic signs of CTD, including in the maxillofacial region. Substantiation of the connection of CTD with dental diseases will make it possible to develop examination and medical examination schemes, increase the effectiveness of comprehensive prevention of dental diseases and rehabilitation of adolescents with combined pathology.The aim is to study the incidence of CTD in adolescents and its relationship with dental diseases in order to develop a scheme of examinations and medical examinations, increase the effectiveness of comprehensive prevention of dental diseases and rehabilitation of adolescents with combined pathology.Materials and methods. A survey of 140 male adolescents aged 15–18 years, students of schools in Smolensk was conducted. When examining the somatic status, generally accepted markers of CTD were taken into account: bone (asthenic type of constitution, scoliotic deformity of the spine, hallux valgus, chest deformities), skin (increased skin extensibility of more than 3 cm), articular (hypermobility of joints) and visceral (changes from the cardiovascular system — prolapses of the heart valves, abnormally located chords; changes from the respiratory organs — polycystic lung disease, trachiobronchial dyskinesia; changes from the urinary system — nephroptosis, kidney doubling; changes from the gastrointestinal tract — visceroptosis, gallbladder anomaly; changes from the blood system — thrombocytopathy, hemoglobinopathy). When examining the dental status, the following generally accepted markers of CTD were taken into account: malocclusion (prognathia, deep bite, their combination), narrowing of the dentition, anomalies of the position of individual teeth, anomalies of soft tissue attachment, gum recession, chronic gingivitis. The diagnosis of CTD and the health group was established by a pediatrician on the basis of clinical recommendations and the order of the Ministry of Health of the Russian Federation № 621 dated 30.12.2003 «On a comprehensive assessment of the health status of children». Factor analysis was used to form a set of signs combining signs of CTD and dental diseases.Results. Of the phenotypic signs of СTD, bone and joint changes were diagnosed in 79,3 % (95 % CI 72,6– 86) of adolescents. In second place in frequency 35 % (95 % CI 27,1–42,9) were signs of СTD of the cardiovascular system and the organ of vision (myopia). 40 % (95 % CI 31,9–48,1) of the examined adolescents were diagnosed with chronic gingivitis, gum recession. Deep bite and prognathia were more common than other malocclusions: in 40,7 % (95 % CI 32,6–48,9) and 17,1 % (95 % CI 10,9–23,4), respectively. The use of factor analysis allowed us to identify four most informative factors (the fi rst of them is the most signifi cant) to characterize the relationship between the signs of CTD and its dental manifestations.Conclusion. The incidence of CTD in males in the age group of 15–18 years is 43 %. The most informative prognostic factor was the relationship of tracheobronchial dyskinesia with prognathia, deep bite, narrowing of the jaws, generalized gingivitis. The interrelation of signs of СTD of the cardiovascular system and bone-joint changes with gum recession, chronic gingivitis, prognathia and deep bite was also revealed.