第三大臼歯抜歯後の下顎第二大臼歯に自家脱灰象牙質マトリックスが与える影響。レトロスペクティブスタディ

Impact of Autogenous Demineralized Dentin Matrix on Mandibular Second Molar after Third Molar Extraction: Retrospective Study.

抄録

このレトロスペクティブな研究の目的は、第三大臼歯抜歯後の下顎第二大臼歯遠位根に焦点を当て、自家脱灰象牙質マトリックス（DDM）移植後の骨治癒を評価することである。2020年1月から2022年9月の間に大臼歯抜歯を行い、一次閉鎖を行わずに初回手術後すぐに（「即時グラフト」）、または6週間（「遅延グラフト」）、抜歯窩にDDMグラフトを移植した20例のレトロスペクティブデータを対象とした。片側のみ移植を受けた患者を対照群とした（＝4）。下顎第二大臼歯の骨欠損は，術前と移植術後4カ月にコーンビームCT（CBCT）を用いて測定した．骨欠損の改善度（すなわち，骨欠損の術前と術後の変化）は，Wilcoxon Signed Rank 検定を用いてコントロール群と移植群間で比較し，即時移植と遅延移植の差は Mann-Whitney U 検定を用いて分析した．感染症やグラフト不全などの合併症は発生しなかった．術前欠損はグラフト群よりもコントロール群で小さかったが（2.98 ± 1.77 と 10.02 ± 3.22 mm, = 0.001），術後欠損は両者で同様であった（それぞれ 2.12 ± 0.59 と 2.29 ± 1.67 mm）．改善率はコントロール群では統計的に有意ではなかったが（22.68 ± 15.36%）、グラフト群では差が認められた（76.70 ± 15.36%, = 0.001）。骨欠損の改善量は、移植時期や患者の性別に影響されなかった。結論として、DDMは第三大臼歯抜歯後の下顎第二大臼歯遠位面の骨欠損を改善することができる。

The purpose of this retrospective study was to evaluate bone healing after autogenous demineralized dentin matrix (DDM) grafts, focusing on the distal root of the mandibular second molar after the extraction of the third. We included retrospective data from 20 patients who had undergone molar extractions (15 male, 41.9 ± 12.0 years) between January 2020 and September 2022 and had DDM grafts implanted on the extraction socket, immediately ("immediate graft") or 6 weeks ("delayed graft") after the first surgery without primary closure. Patients who underwent grafting on only one side were used as the control group ( = 4). Bone defects at the mandibular second molar were measured preoperatively and 4 months after the graft surgery using cone-beam computed tomography (CBCT). Improvement of bone defect (i.e., the change in the bony defect pre- vs. postoperatively) was compared between the control and graft groups using the Wilcoxon Signed Rank test, and the difference between immediate and delayed grafts was analyzed with the Mann-Whitney U test. Complications such as infections or graft failure did not occur. Although pre-operative defects were smaller in the control than in the graft group (2.98 ± 1.77 and 10.02 ± 3.22 mm, = 0.001), post-operative defects were similar in both (2.12 ± 0.59 and 2.29 ± 1.67 mm, respectively). The improvement ratio was not statistically significant in the control group (22.68 ± 15.36%) but a difference was observed in the graft group (76.70 ± 15.36%, = 0.001). The amount of improvement of bone defect was not affected by graft timing or patient sex. In conclusion, DDM can improve bone defect at the distal aspect of the mandibular second molar after third molar extraction.