Onion skin appearance is seen in:
Radiographic picture—Classical onion skin appearance due to cortical layer duplication is seen in both chronic osteomyelitis with proliferative periostitis and Garre’s chronic non suppurative sclerosing osteitis.
Chronic osteomyelitis
Chronic osteomyelitis with proliferative periostitis
Garre’s chronic non-suppurative sclerosing osteitis
Both 2 and 3