An investigation of biomechanics, muscle performance and disability level of craniocervical region of individuals with temporomandibular disorder

In this study, it was aimed to investigate biomechanics, muscle performance and disability level of craniocervical region (CCR) of individuals with temporomandibular disorder (TMD) and compare them with healthy individuals. Fifty individuals who were diagnosed with a TMD after medical examination and investigation was involved as study group while 50 healthy volunteers who don't have any complaint related to TMD was involved as control group. The biomechanics of CCR was statically evaluated by lateral photography (study and control) and radiography (study only) as well as dynamically with digital inclinometer. The muscle performance of CCR was evaluated by the Functional Strength Testing of the Cervical Spine, the disability level of CCR was evaluated by Neck Disability Index, and severity of TMD was evaluated by Fonseca Anamnestic Index for all participants. When the groups were compared, cervical flexion angle (p<0.05) and Neck Disability Index point (p<0.001) significantly higher in study group, Tragus-C7-Horizontal angle (p<0.05), cervical extension angle (p<0.05), right cervical rotation angle (p<0.05), left cervical rotation angle (p<0.001) and values of the muscle performance in each direction (p≤0.001) were significantly lower. When the radiographic measurements of individuals with TMD were compared with normal values, craniocervical angle (p<0.05) was found to be significantly higher. C0-C1 distance in 55.1 % of individuals with TMD, C1-C2 distance in 52 % of them and C2-C7 lordosis angle in 76 % of them were outside of normal ranges. In study group, Neck Disability Index point (ρ=0.523; p<0.001) and values of muscle performance in each direction (p<0.05) are correlated with severity of TMD. The relevant results suggest that it will be beneficial to consider biomechanics, muscle performance and disability level of CCR in the evaluation of TMD and planning of its treatment.