Relationship Between Functional Movements of the Mandible and Core Stability in Young Healthy Adults

Background. Temporomandibular joints (TMJs) have a common neuromuscular connection with neck and scapula, so dysfunction of one or both joints can lead to changes in the spine posture and vice versa. Due to the compensatory mechanism, occurring following TMJ functional disorders, the balance between facial and neck muscle activity is disrupted. A change in any biomechanical unit inevitably results in a change of the posture control system, but there is a lack of research evaluating the relationship between functional movements of the TMJ and trunk stability. The aim. To determine the relationship between core stability and functional movements of the mandible. Methods. The study included 20 participants aged between 20 and 40 years. Participants were tested individually. Tests and measurements selected for the study: trunk stability assessment by functional Dynamic Neuromuscular Stabilization (DNS) tests; assessment of static trunk muscle endurance by McGill endurance tests; assessment of TMJ range of motion using a ruler. Results. Participants performed best on the DNS Supine test with legs raised up, and performed worst on the squat, bear position tests and trunk extension static endurance test. 90% of the participants had impaired range of motion of mandible protrusion, 60% had mandibular depression limitations. The static endurance of trunk flexion was 136.85±96.97 s, extension – 141.45±94.52 s, left side– 98.00±76.08 s, right side– 99.95±96, 99 s. Conclusion. There are strong, moderate and weak linear inverse functional relationships between trunk stability and TMJ mobility. The weaker the core stability, the more restricted the mobility of the mandible. Keywords: temporomandibular joint, TMJ dysfunction, dynamic neuromuscular stabilization, core stability.