Aim: This clinical report evaluated changes in the mandibular condyles of patients diagnosed with osteoarthritis (OA) at the temporomandibular joint (TMJ), who were treated with a modified dental splint. Materials and methods: Four adult patients (age range: 24–47 years) were treated with a dental splint appliance that delivered a low load at the molar region and permitted lateral and protrusive mandibular excursions. An initial magnetic resonance imaging (MRI) scan was performed for diagnosis purpose before treatment. A second MRI scan was conducted after 12 months of treatment to evaluate changes at the TMJ. Results: The observations from the MRI results in the four patients showed positive changes at the end of the study period. The results presented here suggest the treatment provided significantly reduced the forces damaging the tissues covering the surface of the mandibular condyle, such as cartilage and cortical bone, which may be the cause of the OA. In that context, it is suggested that that reduction in the overloading of the TMJ produced by the functional dental splint permitted the recovery of those tissues. Conclusion: The present results support the idea that the tissues composing the TMJ are viable and may respond to positive stimulus. In that way, this report proposes a way to treat those patients with TMJ OA, who may respond when the treatment aims to reduce the overloading forces affecting the TMJ. Clinical significance: This report proposes a noninvasive clinical treatment for patients with TMJ OA, who may respond when the treatment aims to reduce the overloading forces affecting the TMJ.