This study aimed to identify and differentiate the factors that may affect the incidence of temporomandibular joint (TMJ) dysfunction in children with type 1 diabetes. We analyzed the TMJ symptoms, clinical and laboratory parameters of type 1 diabetes in a cohort of 101 consecutive patients. The participants were evaluated regarding the presence of pain in the masticatory muscles, TMJ sounds, mouth opening, maximum mouth opening, lateral and protrusive excursions, and Fonseca scores. The overall cohort showed a mean Fonseca score of 20 ± 13.89, referred to mild TMJ dysfunction. Of patients, 34.65% presented at least one clinical symptom and were defined as having dysfunction. The most frequently recorded symptom was TMJ sounds, presented in 16.8% of children. In subjects with dysfunction compared to those without dysfunction, a significant difference was found at height standard deviation scores, Fonseca scores and maximum mouth opening (p<0.001). HbA1c levels, diabetes duration, age and gender did not reveal any significant differences between the patients with and without dysfunction. Type 1 diabetes is often associated with limited mouth opening and mild TMJ dysfunction. This dysfunction may reflect a more chronic condition and possibly exceeds the prevalence of cheiroartropathy. This study could be a starting point towards enhancing our understanding of clinically evident TMJ involvement in type 1 diabetes.