Introduction. McArdle’s disease is a severe glycogen storage disease characterized by intolerance to exercise; patients have a syndrome of muscle intolerance to stress, associated with myalgia, cramps, fatigue, and muscle weakness. Periodontal disease is a multifactorial pathology of the supporting tissues of the teeth: one of the main factors is the formation of bacterial biofilm; its control favors the prevention and the maintenance of good health of the oral cavity; and some systemic pathologies can worsen the periodontal disease and hinder its therapy. This case report concerns a woman with McArdle’s disease diagnosed with periodontal disease. Material and Methods. A 54-year-old female patient with McArdle’s disease has been diagnosed with Stage 3 generalized periodontitis, Grade B. At the baseline, the patient had 82 pockets with probing pocket depth (PPD) equal to or greater than 4 mm. The patient was instructed in the correct methods of oral hygiene and was advised toothpaste and mouthwash based on probiotics; subsequently, a debridement was performed to remove etiological factors using Dental-Biofilm Detection Topographic Technique (D-BioTECH). Results. After 60 days, the number of pockets was reduced from 82 to 14 overall with PPD ≥ 4 mm and from 50 to 2 pockets with PPD ≥ 5 mm . Full mouth bleeding score (FMBS) increased from 48% to 15% and full mouth plaque score (FMPS) from 73% to 15%. Conclusions. In this case, the use of a correct brushing method combined with the D-BioTECH has reduced the disease state, with the use of probiotics at home to restore and maintain a healthy oral microbiome.