Connective tissue dysplasia as a potential orthodontic risk modifier in adolescent temporomandibular disorders: a PRISMA-oriented scoping review

Temporomandibular disorders (TMD) affect an estimated 34% of the global population, with a projected rise to 44% by 2050; in children the prevalence is approximately 27%. Connective tissue dysplasia (CTD), generalized joint hypermobility (GJH), Ehlers–Danlos syndromes and Marfan syndrome may affect the collagen-rich disc, capsule and ligaments of the temporomandibular joint (TMJ), but evidence on TMD in adolescents with connective tissue disorders is scarce. To map the extent, nature and age distribution of the evidence linking CTD, GJH and hereditary connective tissue disorders with TMD, with adolescents as the primary population, and to identify knowledge gaps relevant to orthodontic practice. A scoping review was conducted according to JBI methodology and reported following PRISMA-ScR. Crossref, PubMed, Google Scholar, Scopus and Semantic Scholar were searched on 27 May 2026. Of 4382 records, 2878 were screened using rule-based term tagging followed by manual screening, a sensitivity re-screening of all excluded records and thematic mapping. Ten records were assessed in full text and 9 were included (4 observational studies in 5 publications, 1 randomized trial, 1 case report, 2 narrative sources); 7 provided direct evidence, all in adults or young adults (314 participants, 175 with hypermobility or Marfan syndrome). No study examined adolescents with CTD, and re-screening of 2862 excluded records identified 576 indirect and 44 background sources but no additional direct evidence. Direct studies reported more frequent TMJ pain, joint sounds, opening deviation and TMD-related disability in adults with joint hypermobility syndrome or Marfan syndrome. Proposed mechanisms (collagen-related vulnerability, ligamentous laxity, COL1A1 polymorphisms, pain sensitization) have not been tested in patients with CTD and TMD. Treatment evidence comprised one uncontrolled physiotherapy series, one case report and one negative prolotherapy trial. Biological and clinical observations suggest a possible association between hypermobility, hereditary connective tissue disorders and TMD, but direct evidence in adolescents is essentially absent. CTD and GJH may be considered potential modifying factors in adolescent TMD; their prognostic value cannot be established and no specific treatment protocol can be recommended. Prospective adolescent studies combining standardized hypermobility assessment, DC/TMD diagnosis and orthodontic outcomes are needed. Not applicable.