In the periodontal disease testing apparatus of the present invention,An X-ray CT apparatus for photographing a part including the teeth, the gingiva and the alveolar bone in the oral cavity to generate volume data of the part,An area setting unit that sets a related area of the inspection target tooth based on the volume dataA defining means for defining a main axis of the inspection target tooth,Correction means for correcting the relevant region such that the main axis of the inspection target tooth coincides with the normal direction of the cross section of the X-ray CT image,Multi-sectional reconstructed image generating means for generating a multi-sectional reconstructed image of the corrected relevant region,A developed image or the like generating means for generating a developed image and a rotated image by carrying out coordinate transformation on the relevant region,Navigation means for indicating a correspondence relationship of spatial coordinates between the multi-sectional reconstructed image, the developed image and the rotated image,In order to improve the quality of the image.本発明の歯周病検査装置は、口腔内の歯、歯肉及び歯槽骨を含む部位を撮影して該部位のボリュームデータを生成するX線CT装置と、前記ボリュームデータに基づいて、検査対象歯の関連領域を設定する領域設定手段と、検査対象歯の主軸を規定する規定手段と、検査対象歯の主軸がX線CT像の断面の法線方向と一致するように関連領域を補正する補正手段と、補正した関連領域の多断面再構成像を生成する多断面再構成像生成手段と、関連領域に座標変換を行って展開像と回転像を生成する展開像等生成手段と、多断面再構成像、展開像、及び回転像間で空間座標の対応関係を指し示すナビゲート手段と、を含むことを特徴としている。
