Pyknodysostosis is a rare, recessive, hereditary, autosomal disease belonging to the group of bone dysplasias. Complications such as osteomyelitis and fractures of the mandible are not uncommon and appear in the most varied forms. We report a case of chronic osteomyelitis with subsequent mandible fracture, which was successfully treated with the use of a reconstruction plate and antibiotic therapy. This article outlines the clinical and radiographic characteristics of this condition based on the clinical case described and proposes an approach regarding the best form of treatment. Considering the risks of fracture subsequent to removal of the graft from long bones as well as the presence of chronic infection, difficult-to-defeat infection, and bone contact on the compression band, the best choice is a more conservative treatment.