日本人集団における上顎第一および第二大臼歯の根管数と根尖凹みの関係をマイクロコンピュータ断層撮影で解析した結果について

Micro-computed tomography analysis of the relationship between root canal number and root concavity in maxillary first and second molars in a Japanese population.

抄録

目的:

本研究の目的は，マイクロコンピュータ断層撮影法を用いて，日本人集団の上顎第一および第二大臼歯の根管形態，および根管数と根尖凹面の深さとの関係を調べることである。

PURPOSE: The aim of this study was to investigate root canal configurations in maxillary first and second molars from a Japanese population, as well as the relationship between the root canal number and root concavity depth, using micro-computed tomography.

方法は以下の通りです。:

日本人の上顎第一大臼歯（N=74）と第二大臼歯（N=70）を用いた。仮想的な水平断面を作成し，根管数と歯根陥没の程度を測定した。中頬側（MB）の根は、根管が1本のグループ1と、根管が2本以上のグループ2に分類した。根管数と根尖の深さの関係は，Mann-Whitney U検定を用いて評価した．

METHODS: Maxillary first (N = 74) and second (N = 70) molars from a Japanese population were used. Virtual horizontal sections were created, and the number of root canals and the degree of root concavity were measured. Mesiobuccal (MB) roots were categorized into Group 1 (with a single root canal) or Group 2 (with two or more root canals). The relationship between the root canal number and root concavity depth was evaluated using the Mann-Whitney U test.

結果:

上顎第一大臼歯と第二大臼歯の3根のうち，MB根の約51％と約35％に2本以上の根管が存在した。上顎第一大臼歯の根尖凹面の深さは、MB根の近心側と遠心側、ファーケーション部から2mmの部分で、グループ1とグループ2で有意に異なっていた（p<0.05）。

RESULTS: Approximately 51% and 35% of the MB roots in the three-rooted maxillary first and second molars, respectively, had two or more root canals. The depths of the root concavities in maxillary first molars differed significantly between Groups 1 and 2 at the mesial and distal sides of the MB root, in the section 2 mm apical to the furcation area (p < 0.05).

おわりに:

上顎第一大臼歯のMB歯根において，根管数と歯根陥没の深さには有意な関係が認められた。上顎第一大臼歯の結石除去と根面清掃には、臨床的に注意深く観察する必要がある。特に、根管治療を受けた後の大臼歯では、セメント質や象牙質の過剰な除去は避けるべきである。

CONCLUSIONS: A significant relationship between the number of root canals and the depth of root concavity in the MB root of the maxillary first molars was observed. Close clinical monitoring is needed during the removal of calculus and cleaning of the root surfaces of maxillary first molars: specifically, excessive removal of cementum and dentin should be avoided, particularly when the molar has already undergone root canal treatment.