Objective <p>This study aimed to compare temporomandibular joint (TMJ) pain, mobility, dysfunction, and functional capacity in people with diabetes with healthy subjects and examine the effect of peripheral diabetic neuropathy symptoms, diabetes duration, and functional capacity on TMJ disorder (TMD) using path analysis with a holistic approach.</p> Methods <p>The study included 40 people with diabetes and 30 healthy subjects. TMJ functionality was evaluated by pain, maximum pain-free mouth opening, functional capacity, and dysfunction. The Michigan Neuropathy Screening Test assessed for peripheral neuropathy symptoms. Quality of life was evaluated using the Ferrans and Powers Quality of Life Index.</p> Results <p>TMD was present in 75% of people with diabetes and 43% of healthy subjects. People with diabetes had more TMJ pain, limited mouth opening, and lower functional capacity compared to healthy subjects (<i>p</i> &lt; 0.05). It was found that peripheral neuropathy symptoms, along with decreased functional capacity and increased duration of diabetes, predict 64.7% TMD and 54.8% low quality of life.</p> Conclusion <p>Peripheral neuropathy symptoms, which increase with prolonged diabetes duration, may reduce functional capacity, leading to TMD and poor quality of life. New approaches should be developed for the prevention and treatment of TMD within the scope of preventive rehabilitation in people with diabetes.</p>