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提要：外周性牙源性肿瘤又称骨外型牙源性肿瘤或软组织牙源性肿瘤，主要发生在牙龈，包括牙源性真性肿瘤及错构瘤。外周性牙源性肿瘤约占所有牙源性肿瘤的4%左右，英文文献表明其中外周性牙源性纤维瘤最多见，其次是外周性成釉细胞瘤及外周性牙源性钙化囊性瘤。外周性牙源性肿瘤临床上容易与牙龈发生的炎症性或反应性病变相混淆，明确诊断依赖组织病理学检查。外周性牙源性肿瘤不包括骨内型牙源性肿瘤穿破骨皮质侵犯牙龈。外周性牙源性肿瘤预后普遍好于相应的骨内型肿瘤，但切除不彻底仍可复发，建议长期随访。

Peripheral odontogenic tumor

Peripheral odontogenic tumor（POT）,either neoplastic or hamartomatous,is a rarely encountered lesion and accounts for about only 4 percent of all odontogenic tumors. They are also known as extraosseous or soft odontogenic tumors. Review of the literature reveals that peripheral fibroma is the most common POT followed by peripheral ameloblastoma and calcifying cystic odontogenic tumor. POTs occur mainly in the gingival tissue,which can be mistaken for other more common exophytic gingival lesions,such as lesions of inflammatory origin or reactive proliferations. The histopathologic examination is necessary for accurate diagnosis. Intraosseous tumors that perforate through the bone to the gingival tissue should be excluded. POTs usually demonstrate better prognosis than their intraosseous counterparts,but long time follow-up is still necessary.