Osteopetrosis is a hereditary disease characterized by increased bone density due to a defect in osteoclast function and malformed bone resorption. 1 Osteopetrosis was originally described in 1904 by the German radiologist Albers-Schönberg. 2 Three types of osteopetrosis have been classified as the malign autosomal recessive type, the intermediate autosomal recessive, and the benign autosomal dominant type. 3 There are crucial clinical and radiological findings in the diagnosis of the osteopetrosis. 1 The clinical findings are commonly skeletal abnormalities such as fragile bone and osteosclerosis and hematologic diseases such as anemia or thrombocytopenia.In addition, vision defect and hearing impairment may occur in the patients. The radiological findings are generally diffuse osteosclerosis, increased cortical bone thickness, and decreased medullary canal diameter. 3 A "marble bone" appearance is usually common in the skeleton, a "bone-in-bone" appearance in the bones of the spine or the hand phalanges, and a "rugger-jersey spine" appearance in the vertebral endplates. 1 Orofacial examination findings of patients with the osteopetrosis are generally unerupted tooth, malformed crowns and roots, enamel hypoplasia, increased dental caries, and tooth loss. 3,4 Furthermore,