Craniomandibular dysfunction (CMD) is a disease associated with pain in the masticatory system and is amenable to treatment. In specialist practices and clinics, however, CMD often appears with other pain symptoms and clinical syndromes other than those of the jaw, frequently resulting in a diffuse and seemingly elusive overall picture. In some specialist articles, CMD is described as a consequence of chronic body pain or fibromyalgia syndrome. Similarly, there is a school of thought that considers comorbidities outside of the craniomandibular region to be a predisposing factor for the development of CMD. Despite the controversial discussion about the possible connections between functional diseases of the craniomandibular system and the other body regions, this case report describes – against the background of the present authors’ clinical experience – how with the co-therapy of symptoms both inside and outside the craniomandibular system, even therapy resistant, whole-body complaints can often be successfully treated. The electromyographic examination as part of the interdisciplinary treatment of CMD and its comorbidities and the valuable collaboration with manual therapists will likewise be demonstrated. Keywords: comorbidities in craniomandibular dysfunction (CMD) and craniocervical dysfunction (CCD), fibromyalgia syndrome (FMS), Widespread Pain Index (WPI), myocentric occlusal splint therapy, electromyography (EMG), transcutaneous electrical neurostimulation (TENS), Arlen’s atlas therapy, manual therapy