不可逆的歯髄炎を有する上顎臼歯部の麻酔成功率に及ぼす解剖学的変数の影響．

The Effect of the Anatomic Variables on the Success Rate of Anesthesia in Maxillary Molars with Irreversible Pulpitis.

抄録

イントロダクション:

不可逆性歯髄炎を有する歯の麻酔を獲得することは、歯内療法診療において最も困難な問題の一つである。本研究の目的は，不可逆性歯髄炎を有する上顎臼歯の麻酔成功率に及ぼす解剖学的変数の影響を評価することである．

INTRODUCTION: Obtaining anesthesia of teeth with irreversible pulpitis is one of the most challenging issues in endodontic practice. The aim of this study was to evaluate the effect of anatomical variables on the success rate of anesthesia in maxillary molars with irreversible pulpitis.

方法:

不可逆性歯髄炎を有する上顎臼歯で，コーンビームCT（CBCT）スキャンを既に実施した患者を本研究の対象とした．麻酔液の浸潤注入後，アクセスキャビティ準備と根管治療時の痛みと治療中の補助注射の必要性を患者に評価させ，麻酔の成功率を記録した．口蓋根から頬側皮質板までの距離は，Planmeca Romexis Viewer の測定ツールを用いて，軸方向と冠方向の両ビューで算出した．データは，カイ二乗検定，t検定，およびROC（Receiver Operating Characteristics）曲線分析によって解析した．

METHODS: Patients who had maxillary molars with irreversible pulpitis and who had already had a cone-beam computed tomographic (CBCT) scan performed were included in this study. After infiltration injection of an anesthetic solution, the success rate of anesthesia was recorded by asking the patients to rate their pain during access cavity preparation and root canal instrumentation as well as their need for a supplementary injection during the treatment. The distance of the palatal root to the buccal cortical plate was calculated by using the Planmeca Romexis Viewer's measuring tools in both the axial and coronal views. Data were analyzed by chi-square and t-tests as well as receiver operating characteristics (ROC) curve analysis.

結果:

上顎第一大臼歯および第二大臼歯47本が本研究の対象であった。全体の麻酔成功率は63.80％であった。口蓋根が頬側皮質板から軸方向で12.34mm以上，冠方向で12.46mm以上離れている歯は，それ以下の歯に比べ麻酔失敗の確率が高かった．また，皮質板と歯根の間の上顎洞の有無は，麻酔効果に大きな影響を与えなかった（P>0.05）．

RESULTS: Forty-seven maxillary first and second molar teeth were eligible to be included in this study. The overall success rate of anesthesia was 63.80%. The palatal roots that had their apex located more than 12.34 mm from the buccal cortical plate in the axial view and 12.46 mm in the coronal view had a higher chance of anesthesia failure compared to the teeth with smaller distances. The presence of the maxillary sinus between the cortical plate and roots had no significant impact on the efficacy of anesthesia (P>0.05).

結論:

口蓋根が乖離している上顎大臼歯では，口蓋根尖から頬側皮質板までの距離が短い歯に比べ，不可逆的歯髄炎治療時に麻酔がうまくいかない可能性が有意に高い．患者が他の理由で既にCBCTスキャンを受けたことがある場合、または患者の記録にCBCTが残っている場合、歯科医師は不可逆性歯髄炎の上顎臼歯の麻酔成功率を予測するためにそれを使用することができる。

CONCLUSION: The potential of anesthesia failure during treatment of irreversible pulpitis in maxillary molars with a divergent palatal root is significantly higher than in teeth with shorter distances from the palatal root apex to the buccal cortical plate. If a patient has already had a CBCT scan done for other reasons or the CBCT is available in his/her records, a dental practitioner can use it to predict anesthesia success for maxillary molars with irreversible pulpitis.