5 patients with established diagnose of PLS are under periodontal treatment at the Department of Periodontology, Center for Dental, Oral, and Maxillofacial Medicine (Carolinum) of the JWG-University Frankfurt am Main. Antiinfective therapy with adjunctive antibiotics has been rendered to all of them and they are under regular and frequent supportive therapy. The Department of Periodontology has contact to additional 5 PLS patients that are edentulous or under periodontal therapy elsewhere.