Chronic osteomyelitis of the jaw is rare in the healthy populations of developed countries and presents with diagnostic and therapeutic challenges. Clinical presentation: Patient 1 presented with a dull, occasionally throbbing pain in the left mandible of 1.5 years duration. There was associated trismus which alternated between improving and worsening. The patient had features mimicking a variant of temporomandibular disorder (TMD). She was misdiagnosed and treated for myogenous TMD without symptom relief. Patient 2 presented with intermittent dull pain with mastication and facial swelling over the right mandible for 1 year. She was treated by the referring dental practitioner for myogenous TMD without symptom relief. Clinical and radiologic findings confirmed a diagnosis of chronic sclerosing osteomyelitis in both cases, and conservative treatment, including antibiotics, relieved the pain with no signs of recurrence. Conclusion: The importance of including chronic osteomyelitis in the differential diagnosis of idiopathic orofacial pain disorders is emphasized. If the management of myogenous TMD is unsuccessful, there is a possibility of a misdiagnosis, and a differential diagnosis, including chronic osteomyelitis, needs to be reconsidered.