Is Generalized Joint Hypermobility Associated with Chronic Painful Temporomandibular Disorders in Young Adults? A Cross-Sectional Study

Background/Objectives: Generalized joint hypermobility (GJH) is a common condition characterized by an increased range of motion across multiple joints. Previous studies have suggested a possible association between GJH and temporomandibular disorders (TMDs). This study aimed to assess the prevalence of GJH in a Portuguese population of young university adults and to explore the relationship between GJH, temporomandibular joint (TMJ) symptoms/clinical findings, chronic painful TMDs, and chronic painful TMDs subtypes (myalgia, arthralgia, or combined myalgia and arthralgia). Methods: A cross-sectional study was carried out in Oporto university institutions, involving 1249 students (18–25 years). GJH was assessed using the Beighton score cut-off ≥ 4. TMJ symptoms and clinical findings were collected using the Research Diagnostic Criteria for TMD protocol, as well as TMD diagnoses. Univariate and multivariate analyses were carried out to examine the associations between GJH and the variables of interest. Results: The overall prevalence of GJH was 41.9%, with females exhibiting a significantly higher likelihood of GJH (p < 0.001). A statistically significant association was found between GJH and TMJ clicking (p < 0.05). Although no overall association was found between GJH and chronic painful TMDs, GJH was significantly associated with the combined diagnosis of myalgia and arthralgia (p < 0.05). Conclusions: The results suggest that GJH may be associated with the more complex subtypes of chronic painful TMDs. However, due to the small size effect of this association, future longitudinal studies with large samples using GJH broader diagnostic criteria are essential to elucidate the relationship between GJH and painful TMDs in asymptomatic nonsyndromic joint hypermobility populations.