Correlation between Temporomandibular Disorders and Leg-length Discrepancies: A Cross-sectional Study

Aim:The study aimed to investigate whether leg-length discrepancies (LLDs) contribute to the development of temporomandibular disorders (TMDs) and to identify an association with any specific types of TMDs.Materials and methods: A total of 143 individuals were randomly selected who reported to the Oral Medicine Clinic and were assessed for their temporomandibular joint (TMJ) and leg length.The chosen participants did not share any specific characteristics.The temporomandibular joint was evaluated using research diagnostic criteria for temporomandibular disorders (RDC/TMD) Axis I and II diagnostic tools.Leg length was measured from the anterior superior iliac spine to the medial malleoli of both ankles, and discrepancies were noted.Following the examination, participants were grouped by TMD diagnosis.The study also considered other important risk factors such as age, gender, occupation, education level, household income, body mass index (BMI), trauma history, jaw disability index, graded chronic pain, depression, and somatization.Chisquare and analysis of variance (ANOVA) identified significant factors for multivariate regression across TMD groups.Results: Temporomandibular disorders were present in 112 (78%) participants.Myofascial pain affected 31 (21.7%), with 44 (30.8%) experiencing it with limited opening.Disc displacement with reduction was 65 (45.5%), and without reduction with limited opening was 1 (0.7%).Arthralgia was reported by 52 (36%), osteoarthritis by 2 (1.4%), and osteoarthrosis by 1 (0.7%).The prevalence of LLD was 84%.Binary logistic regression showed that females and those with chronic pain are more likely to have TMD muscular issues, while higher education levels are linked to a lower risk.For the TMD disc displacement category, LLD and age showed negative associations.Females and those having a graded chronic pain level showed positive associations with TMD arthralgia, osteoarthritis, and osteoarthrosis diagnosis. Conclusion:The study showed no significant association between LLD and muscular disorders, arthralgia, osteoarthritis, or osteoarthrosis but demonstrated a negative association with disc displacement disorders.Clinical significance: Understanding the biomechanical and postural connections between the craniofacial system and the lower limbs is essential to generate evidence to improve TMD diagnosis and determine if postural asymmetries like LLD should be included in the clinical assessment and treatment of TMD patients.