Work-related exposures affecting oral health are important factors of morbidity and decreased quality of life, which may emerge from numerous physical, chemical, or mental occupational exposures. Copper (Cu) is an important trace element, however, it may also cause allergies, depose and accumulate in the body, leading to acute and chronic toxicity. In the present report, we describe a rare phenomenon found during the examination of two professional brass players, after incidentally noting an artefact during magnetic resonance imaging (MRI) scans, which were performed to monitor bone healing after bone augmentation procedures in an unrelated clinical study. During a detailed workup of patient characteristics, data on medical history, lifestyle, professional habits related to playing the instrument, and oral health status were collected. Overall, both patients presented with similar histories, and the differences from the context of this study were not relevant; however, both brass players were using an uncoated Cu mouthpiece for over 15 years. Based on the imaging findings (a shadow in the area of the lips on the MRI images) and the organoleptic evaluation of the lips and mucosa of the individuals (temporary faint green discoloration), it is most likely that the brass players were affected by oxidized Cu accumulation in the lip. In contrast to several professions, musicians are usually not required by law to attend obligatory occupational health check-ups, which may facilitate the occurrence of such exposures in musicians. Clinicians should be on the lookout for brass players involved in the profession for a long time, who may have used the mouthpieces for an extended period of time, in addition to musicians affected by Wilson’s disease. In patients affected by this phenomenon, diagnostics of oral cancer and prosthodontic procedures may be cumbersome, due to the detrimental impact on the utility of MRI imaging from artefact-formation and scattering.