Effect of temporomandibular joint sensory receptors on functional jaw movements following intra-articular anesthesia during gum-chewing

Abstract

We attempted to clarify the role of the temporomandibular joint (TMJ) sensory receptors on jaw movement. Eight young healthy volunteers participated in this study. All volunteers had a full complement of teeth, optimal occlusion and an absence of any symptoms of TMJ or masticatory muscle dysfunction. Functional jaw movements were monitored before and after saline was injected into the right superior temporomandibular joint cavity. On a different day, functional jaw movements were monitored before and after 2% lidocaine was injected into the right superior temporomandibular joint cavity for sensory deprivation. Recordings of jaw movement were made by monitoring movements of the lower incisors using a model K7 Mandibular Kinesiograph (MKG ; Myotronics Research, Seattle, WA, USA) during unilateral gum-chewing.
Following anesthsia to the TMJ on one side, the jaw movements of the chewing path had a more variable pattern in the frontal plane, and the cycle time of each stroke after anesthsia was longer than normal. These findings suggest that sensory receptors in the TMJ contribute to functional jaw movements.