Le My Huy Thuc, Noor Hayaty Abu Kasim, Zaini Zuraiza Mohamad, Dom Sulaiman Md, Ibrahim Norliza, Radzi Zamri Bin
Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia.
Department of Restorative Dentistry, Wellness Research Cluster, University of Malaya, Kuala Lumpur, Malaysia.
Korean J Orthod. 2019 Jul;49(4):235-245. doi: 10.4041/kjod.2019.49.4.235. Epub 2019 Jul 22.
This study examined bone microstructure restoration after rapid maxillary expansion (RME) with and without corticotomy over multiple retention periods.
Eighteen male Dorper sheep were randomly distributed into three groups (n = 6 each group): group 1, RME with corticotomy on the buccal and palatal sides; group 2, conventional RME treatment; and group 3, no treatment. Post-RME, trabecular bone microstructure and new bone formation were evaluated by using microcomputed tomography (microCT) and histomorphometry after a 4- or 12-week retention period. Intergroup differences in bone quality and bone remodeling were analyzed by using two-way analysis of variance with Bonferroni test.
The bone volume fraction (bone volume [BV]/total volume [TV]) values relative to the control in groups 1 and 2 were 54.40% to 69.88% after the 4-week retention period and returned to approximately 80% after the 12-week retention period. The pooled BV/TV values of the banded teeth in groups 1 and 2 were significantly lower than those of the control after the 4-week retention period ( < 0.05). However, after the 12-week retention period, the pooled BV/TV values in group 2 were significantly lower than those in groups 1 and 3 ( < 0.05). Histomorphological analysis showed that the new bone formation area in group 1 was approximately two to three times of those in group 2 and control.
Corticotomy significantly enhanced the restoration of bone quality after the retention periods for banded teeth. This benefit might result from the increased new bone formation after corticotomy.
本研究考察了在多个保持期内，有或没有进行皮质切开术的快速上颌扩弓（RME）后骨微观结构的恢复情况。
18只雄性杜泊绵羊被随机分为三组（每组n = 6）：第1组，颊侧和腭侧均进行皮质切开术的RME；第2组，传统RME治疗；第3组，不进行治疗。RME后，在4周或12周的保持期后，使用微型计算机断层扫描（microCT）和组织形态计量学评估小梁骨微观结构和新骨形成。采用双向方差分析和Bonferroni检验分析组间骨质量和骨重塑的差异。
在4周保持期后，第1组和第2组相对于对照组的骨体积分数（骨体积[BV]/总体积[TV]）值为54.40%至69.88%，在12周保持期后恢复至约80%。在4周保持期后，第1组和第2组带环牙的合并BV/TV值显著低于对照组（<0.05）。然而，在12周保持期后，第2组的合并BV/TV值显著低于第1组和第3组（<0.05）。组织形态学分析表明，第1组的新骨形成面积约为第2组和对照组的两到三倍。
皮质切开术在带环牙保持期后显著增强了骨质量的恢复。这种益处可能源于皮质切开术后新骨形成增加。
