A case of a huge maxillary odontoma

We describe a maxillary odontoma 48mm in longest diameter that was removed intraorally. An 18-yearold woman lacked right upper molar teeth and had a diffuse and hard swelling in this region. A computed tomographic scan showed a radiopaque mass lesion occupying most of the right sinus. While attempting to preserve the surrounding tissues, the lesion was segmented into several pieces by using bars and chisels and was then extracted. The reconstructed lesion measured 48 ×40×32mm. It was a complex odontoma. Odontoma consists of tooth elements, which can make cutting difficult. However, the hardness of odontomas has not been examined. We measured the microvickers hardness of the odontoma, as compared with that of teeth and cortical bones. The median values of enamel, dentin, and cortical bone were 312.0, 65.1, and 28.4, respectively. The median hardness of odontoma was 33.9, but hardness widely ranged from 13.6 to 295.1. The median hardness of the odontoma in our patient was greater than that of cortical bone, and cutting a long distance was not necessarily easy. However, the lesion could be removed with minimal invasion of the surrounding tissues. There has been no sequela, and the patient's progress remains good as of 21 months after the operation.