Correlation between generalised joint hypermobility and temporomandibular joint disc displacement in adolescent patients: Magnetic Resonance Imaging study

Aim Temporomandibular disorders (TMD), in particular disc displacement, are recognised to have a multifactorial aetiology. Ligamentous laxity has been suggested as a potential risk factor for TMD. Ligamentous laxity can lead to generalised joint hypermobility (GJH) involving multiple joints, including the temporomandibular joint (TMJ). The aim of this work is to evaluate the correlation between GJH and disc displacement (DD) assessed on magnetic resonance images (MRI) of the TMJ in adolescent patients. Materials and methods The study was included 40 adolescent patients (10-16 years), divided into two groups, a Study Group (SG), composed of 20 subjects with GJH, and a Control Group (CG), composed of 20 subjects without GJH. The GJH was assessed by the Beighton test with a threshold value of >= 4. The severity of the TMD was determined using the Fonseca Questionnaire and a clinical evaluation of the type of TMD. The condylar-discal relationship and the condylar mobility of the TMJ were evaluated by MRI. Pearson's chi 2 Test was performed for the analysis of the statistical correlation. Results A statistically significant correlation emerged between GJH and DD (p = 0.006) and in the SG the most frequent type of disc displacement was the disc displacement without reduction. According to the Fonseca Test the most frequent TMD severity grade in patients with GJH was the mild degree (p = 0.019). There was also a correlation between GJH and type of TMD and the articular type was the most frequent (60%) in the SG (p = 0.038). No correlation was observed between GJH and the joint mobility of the TMJ. Conclusion This study suggests that adolescents with GJH have a greater risk of developing TMJ disc displacement, especially disc displacement without reduction.