Fig. 2From: Impact of mucosal biofilm and bony osteitis on chronic rhinosinusitis with nasal polypsa Bone grade I with periosteal thickening (arrow). b Bone grade II with periosteal thickening (star) and osteoblastic activity (arrow). c Bone grade II with osteoblastic and osteoclastic activity (arrow). d Bone grade III with irregular wide bony trabeculae (arrow)Back to article page