コーンビームCTを用いた根尖骨折の診断：垂直根尖骨折と水平根尖骨折の違い．

Diagnosis of root fractures using cone-beam computed tomography: difference of vertical and horizontal root fracture.

• Fumi Mizuhashi
• Ichiro Ogura
• Yoshihiro Sugawara
• Makoto Oohashi
• Ryo Mizuhashi
• Hisato Saegusa

抄録

目的:

本研究の目的は，コーンビームコンピュータ断層撮影法（CBCT）を用いて，歯根の垂直骨折および水平骨折の発生状況を調査することであった．

OBJECTIVES: The aim of this study was to investigate the occurrence of vertical and horizontal root fractures using cone-beam computed tomography (CBCT).

方法:

歯根破折の診断のためにCBCTを受診した51例のCBCT画像をレビューした。その結果，歯髄活力や歯の種類に関連して，垂直根破折と水平根破折の発生状況を調査し，クロス集計により解析を行った．また，垂直根破折の破折方向および破折角度を調査し，クロス集計およびKruskal-Wallis検定によりそれぞれ解析した．

METHODS: We reviewed the CBCT images of 51 patients who were examined by CBCT for the diagnosis of root fracture. The occurrences of vertical and horizontal root fractures were investigated concerning the pulpal vitality and the kind of tooth, and analyzed by cross-tabulation. The fracture direction of vertical root fracture and the fracture angle were also investigated, and analyzed by cross-tabulation and Kruskal-Wallis test, respectively.

結果:

歯根破折の発生状況は，歯牙と非歯牙で統計学的に有意に異なっていた（p=0.044）．また，前歯，前臼歯，大臼歯では，縦・横方向の歯根破折の発生状況が異なっていた（p=0.004）．外傷を受けた歯の種類は前歯のみで、水平根破折では数が多かった。また，非外傷歯では，歯の種類によって垂直骨折と水平骨折の発生状況が異なり(p=0.007)，前臼歯では水平骨折よりも垂直骨折の方が多くなっていた．また，骨折の方向に違いはなかったが，歯の種類によって骨折角度に違いがあった(p=0.027)．

RESULTS: The occurrence of vertical and horizontal root fractures was statistically significantly different between vital tooth and non-vital tooth (p = 0.044). The occurrence of vertical and horizontal root fractures was also different among anterior, premolar, and molar teeth (p = 0.004). The kind of tooth on traumatized tooth was only anterior teeth and the number was larger on horizontal root fracture. The occurrence of vertical and horizontal root fractures on non-traumatized tooth was different among the kind of tooth (p = 0.007), and the number of vertical root fracture was larger than that of horizontal root fracture on premolar teeth. Fracture direction was not different, but the fracture angle was different among the kind of tooth on vertical root fracture (p = 0.027).

結論:

その結果，垂直根破折の数は非生歯で大きく，水平根破折の数は生歯で大きくなることが示唆された．また，小臼歯では垂直根破折の数が多かった．

CONCLUSIONS: The results suggested that the number of vertical root fracture was larger on non-vital tooth and that of horizontal root fracture was larger on vital tooth. The number of vertical root fracture was larger on premolar teeth.