Mandibular odontogenic cyst atypically extended into the submandibular region with thickened bone formation: A case report

Odontogenic cysts can cause thinning and expansion of the surrounding cortical bone; however, bone formation extending into the submandibular region, resembling periosteal reactions, is rarely observed in odontogenic cysts.A 52‐year‐old man presented with painful submandibular swelling and dyspnea. Computed tomography revealed an extensive mandibular cystic lesion extending to the submandibular region accompanied by thickened bone formation, mimicking lobulated shell‐type periosteal reaction. Percutaneous cystectomy with extensive mandibular bone resection was performed.Prolonged existence of extensive cystic lesion and inflammatory stimulation may result in bone elongation into the submandibular region, mimicking periosteal reaction.