Inflammatory paradental cyst (IPC) in the mandibular premolar region in children

OBJECTIVES: We investigated the occurrence of inflammatory paradental cysts (IPC) in the mandibular premolar, and demonstrated the points of difference with regard to diagnostic features between IPC and dentigerous cysts (DC). MATERIAL AND METHODS: We analyzed the radiographs and histology of 60 cases with a cystic lesion associated with inflammation in the mandibular premolar region based on diagnostic criteria as IPC. RESULTS: In 4 out of 60 cases, we diagnosed the 4 cysts as IPCs in the mandibular premolar region, and recognized that one form of IPC was similar to a mandibular infected buccal cyst. The other 56 non-IPC cases were diagnosed as DC. On the IPCs, the permanent tooth normally erupted in all 4 cases after treatment, but in one case, the IPC recurred. CONCLUSIONS: The present investigation suggested that we might have misdiagnosed IPCs in the mandibular premolar region as DC to date. It is important to consider the differences between IPC and DC with regard to the causes of recurrence during treatment of IPC.