What is condensing osteitis, how does it affect the tooth root, and what are the treatment options? Explained in 3D Condensing osteitis (focal sclerosing osteomyelitis) is an increase in bone formation around the tooth root apex, usually due to a prolonged bacterial infection. It often occurs with irreversible pulpitis, pulp necrosis, or chronic apical periodontitis, especially in children and young adults. The lesion typically occurs around the root apices of mandibular molars or premolars. Key