CAJ | 학술논문

背景:牙齿压低移动更容易造成牙根吸收,以往针对矫正引起牙根吸收的研究或基于X射线片的回顾性临床研究,或因无法精确控制压低力量,结果误差较大.目的:建立应用微型种植体支抗压低犬切牙的实验动物模型,观察牙齿压低移动过程中牙周、牙根骨组织学的变化,以评价该治疗方法的可行性及安全性.方法:将9只犬分为5组:对照组1只,未加力;1周、2周、4周、12周组每组2只,在上颌两侧第二、三切牙牙根之间唇侧的牙槽间隔处植入微型种植体作为支抗,每侧施加100 g的牵引力压低上颌两侧第一、二切牙,分别于加力后1,2,4,12 周(主动加力4周,撤力后保持8周)时处死动物,将第一、二切牙连同牙龈、牙槽骨完整切取,制作组织学标本,苏木精-伊红染色,观察牙周、牙根的组织学变化.结果与结论:与对照组相比,1周组组织改建主要在根尖部和牙槽嵴顶,牙槽骨及牙骨质可见吸收,牙周膜局部出现玻璃样变性;2周组骨质吸收程度及范围明显扩大,吸收有从根尖部向根中及颈部扩展的现象;4周组骨质吸收仍然活跃,牙周膜玻璃样变性消失;12周组牙槽骨及牙骨质表面显著修复,骨陷窝新骨沉积,牙周膜排列有序.提示应用微型种植体支抗压低牙齿,早期组织变化主要在根尖部和牙槽嵴顶,表现为牙槽骨及牙骨质吸收、牙周膜玻璃样变性.随着压低力的持续,吸收程度及范围扩展.停止加力后,牙根及牙周组织逐渐修复.
배경:아치압저이동경용역조성아근흡수,이왕침대교정인기아근흡수적연구혹기우X사선편적회고성림상연구,혹인무법정학공제압저역량,결과오차교대.목적:건립응용미형충식체지항압저견절아적실험동물모형,관찰아치압저이동과정중아주、아근골조직학적변화,이평개해치료방법적가행성급안전성.방법:장9지견분위5조:대조조1지,미가력;1주、2주、4주、12주조매조2지,재상합량측제이、삼절아아근지간진측적아조간격처식입미형충식체작위지항,매측시가100 g적견인력압저상합량측제일、이절아,분별우가력후1,2,4,12 주(주동가력4주,철력후보지8주)시처사동물,장제일、이절아련동아간、아조골완정절취,제작조직학표본,소목정-이홍염색,관찰아주、아근적조직학변화.결과여결론:여대조조상비,1주조조직개건주요재근첨부화아조척정,아조골급아골질가견흡수,아주막국부출현파리양변성;2주조골질흡수정도급범위명현확대,흡수유종근첨부향근중급경부확전적현상;4주조골질흡수잉연활약,아주막파리양변성소실;12주조아조골급아골질표면현저수복,골함와신골침적,아주막배렬유서.제시응용미형충식체지항압저아치,조기조직변화주요재근첨부화아조척정,표현위아조골급아골질흡수、아주막파리양변성.수착압저력적지속,흡수정도급범위확전.정지가력후,아근급아주조직축점수복.
BACKGROUND: Tooth intrusion easily leads to root resorption. Previous studies regarding orthodontic treatment-caused tooth root resorption or retrospective clinical studies based on X-ray films have great errors in outcome evaluation because of intrusion force which cannot be precisely controlled. OBJECTIVE: This study established dog models of mini-implant anchorage for incisor intrusion to observe the histological changes of tooth root and periodontal tissue and to evaluate the feasibility and safety of mini-implant anchorage for incisor intrusion. METHODS: Nine dogs were assigned to one control group (n = 1) and four experimental groups per time to sacrifice (1, 2, 4 and 12 weeks; n = 2 dogs for each experimental group). No force was added to the control group. In the experimental groups, mini-implant as an anchorage was placed in the buccal alveoli between maxillary second and third incisors on each side. A traction force of 100 g was imposed to each side to intrude the maxillary first and second incisors on each side. At 1, 2, 3, and 4 weeks (traction force was imposed for 4 weeks and after withdrawal of extraction force, mini-implant was retained in place for 8 weeks), dogs were sacrificed. The first and second incisors together with gingival and alveolar bone were completely resected to prepare histological specimens. Following hematoxylin-eosin staining, histological changes of tooth root and periodontal tissue were observed. RESULTS AND CONCLUSION: Compared with the control group, in the 1-week group, histological changes were primarily at the root tip and alveolar ridge crest, alveolar bone and cementum were absorbed and peridental membrane presented glassy degeneration in local region; in the 2-week group, bone resorption degree and range were obviously enlarged, and bone resorption developed from root tip, root middle part to cervical part; in the 4-week group, bone resorption was still active and the glassy degeneration of peridental membrane disappeared; in the 12-week group, significant improvement in alveolar bone and cemental surface was observed, bone lacuna had deposition of newly formed bone, and peridental membrane was orderly arranged. These findings reveal that in the mini-implant anchorage for dog incisor intrusion, early histological changes primarily appear in the root tip and alveolar ridge crest, presenting as alveolar bone and cemental resorption and the glassy degeneration of the peridental membrane. Bone resorption extent and range expand with the persistence of traction force. After withdrawal of traction force, tooth root and periodontal tissue were gradually repaired