Medication-related osteonecrosis of the jaws (MRONJ) is a relatively new disease. MARX reported first cases in 2003. MRONJ relates to oral and parenteral bisphosphonates as well as to the so-called target cancer therapies but the list of medications only grows. Although MRONJ is a relatively rare condition, it can be associated to significant morbidity with feeding limitations and intense pain. More severe cases can lead to potentially life-threatening infections. Every patient initiating bisphosphonate and/or target cancer therapy must visit a dentist before starting medication because preventive measures for MRONJ are much more effective compared to surgical management of the lesions. Surgical resolution can be especially difficult to obtain in the coexistence of certain complication factors like wider bone exposures, history of nitrogen containing bisphosphonates use (mainly zolendronate) and immunodeficiency. Recently, researchers have given attention to laser therapy associated to photosensitive agents as a possible option to management of some MRONJ lesions. Our case report demonstrates the use of photodynamic therapy in a denosumab related lesion in the mandible. It seems that denosumab related lesions are more amenable to treatment and total resolution because of the marked differences between its chemical and metabolic characteristics when compared to bisphosphonates.