Langerhans' Cell Histiocytosis in a 5‐Year‐Old Girl: Evidence of Periodontal Pathogens

Background:Langerhans' cell histiocytosis (LCH) is a rare disorder characterized by Langerhans' cell proliferation in various organs or tissues. When periodontal tissue is involved, clinical manifestations can vary from gingival recession and pocket formation to severe alveolar bone loss. This case report describes periodontal pathogens found in the pockets of involved primary teeth. Methods:A 5‐year‐old girl with LCH presented with loose teeth. Intraoral examination and radiographs revealed deep pockets and severe bone loss around all primary molars. Bacterial samples were obtained from saliva and subgingival plaque and analyzed for the presence of five periodontopathic bacteria using a polymerase chain reaction (PCR) method. Due to severe periodontal destruction, all primary molars were extracted, and a gingival biopsy was taken from tooth T to confirm the diagnosis of LCH. Results:The biopsy specimen revealed the histologic features of LCH. The patient was diagnosed as having periodontitis as a manifestation of LCH. PCR results of subgingival plaque from LCH‐affected molars indicated the presence of Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, and Prevotella intermedia. However, Actinobacillus actinomycetemcomitanswas absent from these teeth. No tested bacteria were found in the non‐affected anterior teeth. Conclusions:The bacteria commonly associated with periodontal disease were detected in subgingival plaque samples from this LCH patient. More microbiological data are required to understand the role of these bacteria in LCH‐associated periodontal destruction.