Résumé
Introduction: Pycnodysostosis, or Toulouse Lautrec's disease, is a rare lysosomal genetic disease with an autosomal recessive transmission, and it is classified as one of the osteo-chondro-dysplasias (ICD-10). Patients with pycnodysostosis manifest with several clinical features, including osteosclerosis, bone fragility, short stature and acro-osteolysis of the distal phalanges. Maxillofacial symptoms mainly associate a lack of maxillary and mandibular growth, open mandibular angle, and significant dental crowding. Observations: This work presents the case of two sisters suffering from pycnodysostosis as part of a family affected by it (mother and maternal aunt also affected). The first patient has received regular monitoring and oral care. The second one suffered from spontaneous mandibular osteomyelitis, which was difficult to treat and cure. Discussion: Oral symptoms of this disease make maintaining oral hygiene difficult and predispose to tooth decay and periodontal disease. The most common complications are mandibular osteomyelitis and pathological fractures. Pycnodysostosis must be differentiated from osteopetrosis and cleidocranial dysplasia. Conclusion: These cases illustrate the difficulty of managing the patients suffering from pycnodysostosis, whose treatment may be difficult.