過去に成功した再生歯内療法処置の矯正移動後の長期的合併症。4年、8年、11年後の3種類の合併症の報告

Long-term Complications of Previously Successful Regenerative Endodontic Procedures after Orthodontic Movement: A Report of 3 Different Complications after 4, 8, and 11 Years.

抄録

再生歯内療法処置の晩期合併症に関する文献は乏しい。本論文の目的は、過去に成功した再生歯内療法を長期的に追跡調査した結果、矯正力作用後に異なる合併症を発症した3症例を報告することであった。最初の症例は、8歳女性で、自然整復術に成功した後、壊死した既侵入歯（歯番号21）に再生歯内療法を施行した。5年後の経過観察では，21番の歯は問題なく治癒し，歯根の発達，象牙質の肥厚，歯髄の活力の回復が認められた．4年後，軽度の力で2年間矯正治療を行った．11年後の経過観察では，重度の外侵襲性歯頸部吸収が認められ，抜歯を余儀なくされた．2例目は6歳女性の患者さんで、11番の歯が側方脱臼の怪我をしました。受傷後6ヶ月で症状および変色を呈し，歯髄活力検査で陰性となった．シングルステップ再生歯内療法を行い，3年後の経過観察では，連続発根，象牙質壁の肥厚，歯根端閉鎖が達成された．矯正治療開始2ヵ月後に症候性歯根端部歯周炎を発症した．根管治療により治癒し，矯正治療を継続した．3例目は、既報の再生歯内療法が成功した症例で、矯正力負荷後6ヶ月で穿孔性内部吸収が発生した。根管治療で内部吸収を阻止し、バイオセラミック封鎖で吸収欠損を修復し、矯正治療計画を変更した。以前は再生に成功していた症例でも、矯正力を加えると外侵襲性歯頸部吸収、再生組織壊死、内部吸収を起こす可能性がある。再生歯内療法が成功した歯の適切な矯正管理に関するベストプラクティス／エビデンスに基づくガイドラインは欠如している。可能な限り、注意深く観察し、矯正治療の一部または全部を除外することが必要であろう。場合によっては、矯正開始前の予防的根管治療が考慮されるかもしれません。

There is a paucity of literature on late complications of regenerative endodontic procedures. The aim of this article was to report 3 cases of previously successful regenerative endodontic procedures with long-term follow-up that developed different complications after the application of orthodontic forces. In the first case, an 8-year-old female patient received a regenerative endodontic procedure in her previously intruded tooth (tooth no. 21) that had been rendered necrotic after a successful spontaneous repositioning procedure. The 5-year follow-up revealed uneventful healing, continuous root development, dentinal wall thickening, and regaining of pulp vitality for tooth no. 21. Four years later, the patient received orthodontic treatment with mild forces that lasted 2 years. The 11-year follow-up revealed severe external invasive cervical resorption, and the tooth had to be extracted. In the second case, a 6-year-old female patient suffered a lateral luxation injury in tooth no. 11. Six months after the injury, the tooth developed symptoms and discoloration and tested negative in pulp vitality testing. Single-step regenerative endodontic procedures were applied, and successful continuous root development, dentinal wall thickening, and apical closure were achieved at the 3-year follow-up. Two months after the initiation of orthodontic treatment, the tooth developed symptomatic apical periodontitis. Root canal treatment was performed to treat the disease, and the orthodontic treatment was continued. In the third case, a previously published successful regenerative endodontic procedure developed a perforating internal resorption 6 months after the application of orthodontic forces. The internal resorption was arrested with root canal treatment, the resorptive defect was repaired with bioceramic obturation, and the orthodontic treatment plan was modified. Previously successful regenerative cases might develop external invasive cervical resorption, regenerative tissue necrosis, or internal resorption after the application of orthodontic forces. Best practice/evidence-based guidelines on the appropriate orthodontic management of successful regenerative endodontic therapy teeth are lacking. Whenever possible, careful monitoring and partial or complete exclusion off orthodontic treatment might be necessary. In some cases, preventive root canal treatment before the initiation of orthodontic movement might be considered.