The aim of this observational case-control study was to investigate the effect of diabetic peripheral neuropathy symptoms on temporomandibular joint functionality in patients with type 2 diabetes.

The number of participants planned to be included in the study was decided with the G-Power programme. While calculating the number of individuals to be included in the study, it was calculated that the sample size to obtain an effect size of 0.6 for the purpose of evaluation within the 95% confidence interval in a way to provide 80% study power at 5% Type 1 and 20% Type 2 error limits should be 74 (n=37) individuals. This study included 70 individuals (DM study group=40 individuals, control group=30 individuals).

Peripheral neuropathy symptoms of all participants were evaluated with the Michigan Neuropathy Screening Test. In the evaluation of TMJ functionality, the presence of pain, maximum pain-free mouth opening, mandibular dysfunction and dysfunction were assessed with the help of scales. Duration of diabetes mellitus was recorded and quality of life was evaluated with Ferran Powers Quality of Life Index.

Inclusion Criteria:

• Individuals diagnosed with type 2 DM

Exclusion Criteria:

• Having diabetic foot ulcer,
• Mini Mental Test score below 24,
• History of psychiatric illness, cancer, neurological problems, congenital anomalies, musculoskeletal problems, systemic disease, facial paralysis, surgical operation related to spine, abdomen and/or TMJ problem
• Receiving any treatment related to spine and TMJ in less than 6 months

The study group included individuals aged between 48-78 (min-max) years who were diagnosed with type 2 DM in the treatment units of Harran University Training and Research Hospital, while the control group included age and gender homogeneous healthy individuals without a diagnosis of DM.