下顎第三大臼歯の萌出状況と舌骨の厚さとの関係】.

[Relationship between eruption status of mandibular third molars and thickness of the lingual bone].

• Cheng Huang
• Chun Zhou
• Min-Hua Xu
• De-Rong Zou

抄録

目的:

下顎第三大臼歯の萌出状況と舌骨の厚さとの関係を推定する。

PURPOSE: To estimate the relationship between the eruption status of the mandibular third molars and the thickness of the lingual bone.

方法:

2016年1月から2018年12月までに下顎第三大臼歯抜歯を受けた187例のコーンビームCT（CBCT）データを抽出した。GALIEOS Viewerソフトウェアを用いて第三大臼歯の中根および根尖レベルでの舌骨厚を測定し、下顎第三大臼歯の萌出状況と舌骨厚との関係を推定した。ウィルコクソン検定、一変量および多変量ロジスティック回帰分析にはSPSS 22.0ソフトウェアパッケージを使用した。

METHODS: Cone-beam CT (CBCT) data of 187 patients who underwent mandibular third molar extraction from Jan 2016 to Dec 2018 were selected. Lingual bone thickness at the levels of mid-root and root-apex of the third molars were measured using GALIEOS Viewer software, and the relationship between the eruption status of the mandibular third molars and the thickness of the lingual bone was estimated. SPSS 22.0 software package was used for Wilcoxon test, univariate and multivariate logistic regression analysis.

結果:

第三大臼歯の中根部の舌骨の厚さの平均値は、根尖部の厚さよりも有意に少なかった（P<0.01）。中根部の舌骨厚と第三大臼歯の中骨角との間には有意な相関が認められた．中顎および水平方向に衝撃を受けた第三大臼歯の中根部の舌骨の厚さは有意に薄くなっていた（P<0.01）。根尖部の舌骨厚と第三大臼歯の圧迫深さには有意な相関があった．中位および低位の第三大臼歯では、根尖部の舌骨の厚さが有意に薄くなっていた(P<0.05)。

RESULTS: The mean thickness of the lingual bone at the mid-root of the third molars was significantly less than that at the root apex (P<0.01). There was a significant correlation between the thickness of the lingual bone at the mid root and the mesiodistal angulations of the third molars. The thickness of the lingual bone at the mid root of mesioangularly and horizontally impacted third molars were significantly thinner (P<0.01). There was a significant correlation between the thickness of the lingual bone at the root apex and the impaction depth of the third molars. The thickness of the lingual bone at the root apex of medium and low positioned third molars were significantly thinner (P<0.05).

結論:

舌骨の厚さは下顎第三大臼歯の萌出状況と関連している。中顎第三大臼歯は舌骨が薄くなる危険因子と考えられており、抜歯時の舌板骨折を予防する必要があります。

CONCLUSIONS: The thickness of the lingual bone is associated with the eruption status of the mandibular third molars. Mesially angulated and lower positioned third molars are considered as the risk factors for the thinner lingual bone, so that lingual plate fracture should be prevented during tooth extraction.