[Histologic, ultramicroscopic, and microradiographic study of histiocytosis X lesions in the periodontium].

Examination under an optical microscope of a radiolucent mandibular lesion showed a proliferation of histiocytes. Upon further examination of electron micrographs, the lesion showed the presence of Langerhans cell granules, within the histiocytes, thus confirming the clinical diagnosis of Hand-Schüller-Christian's disease. Microradiographic study of the canine tooth and the surrounding alveolar bone shows alveolar and root resorption, as well as signs of osteomalacia.