Temporomandibular joint (TMJ) function on selected postural variables with analysis of changes in equivalent reactions
Authors: Broczkowska Zuzanna , Żurawski Arkadiusz , Śliwiński Zbigniew 
Published: December 2024

Introduction. The position and tensions in the temporomandibular joint directly affect the cervical spine by changing the position of the cervical lordosis through a direct connection between the TMJ joint and the C0-C1 segment. According to the theory of tensegrity occurring in the human body, a change in the position in one segment can affect the other areas of the body. Changes in the tension of the structures in the joint can therefore affect the parameters of the equilibrium reactions. In the current literature review, there is little research on the relationship between the temporomandibular joint and balance. Study aim. The aim of the study was to analyze the influence of the temporomandibular joint position on the parameters of cervical spine lordosis depth, body posture and balance reactions in a group of young adults. Methods and materials. A total of 43 people aged 18-26 were examined. The tests were conducted in a static form using the DIERS posture lab system in three settings: TMJ joint in a neutral position, TMJ with maximum jaw tension and opening in maximum possibilities. People with orthodontic appliances and people whose jaw opening range was limited (less than the width of their four fingers) were excluded from the study. Parameters used for analysis: Depth of cervical lordosis [mm], Amount of head protraction [mm], Trunk inclination, Depth and angle of lumbar lordosis, Pelvic inclination, pelvic rotation, and variables defining parameters of equivalent reactions and variables defining parameters of equivalent reactions: Left foot load [%], Right foot load [%], Forefoot load [%], Heel load [%], Maximum left foot pressure [N], Maximum right foot pressure [N], Left foot contact area [cm2], Right foot contact area [cm²], Lateral movement COP (max) [mm], Total lateral movement COP [mm], Total front/back movement COP [mm], COP area. Statistica program was used for statistical analysis. Tests for normality distribution (Shapiro-Wilk), Chi-square test were performed, and correlations were examined with Spearman’s test. Results. Studies conducted on a group of young adults may suggest the influence of the temporomandibular joint position on changes in equivalent changes. The results of descriptive statistics show significant changes in the average results, including around foot load or COP surface. The highest average results were observed in the case of opening the TMJ joint, where deviations in the area of equivalent reaction changes showed the highest average results. The results of both descriptive statistics and correlations did not show significant differences between the joint position and trunk variables. The differences between the was minimal. Conclusions. Changes in the position and tension of the temporomandibular joint affect the position of the cervical spine and balance parameters. For the position with open TMJ positioning, there is a correlation with the variables of the contact area of the right and left foot with the ground. There are no changes in body posture. It cannot be stated that the position of the temporomandibular joint significantly affects the variables of body posture.