牙根尖周圍反應性骨碎形維度值於根管治療前後變化之研究

Abstract

研究目的： 本研究目的是運用碎形將根管治療後反應性骨之變化給予數值化觀察其變化；並假說成功根管治療過後反應性骨碎形維度值會比治療前下降。 研究設計： 首先從19位患者治療前和治療後口腔X光數位元影像取出兩組ROI(Region of Interesting)，再運用數學型態法去擷取牙根尖周圍影像反應性骨之骨小樑形態，搭配方格記數法去估算被擷取出小樑骨型態的碎形維度值。 研究結果： 第一組ROIs中19位患者中17位在成功根管治療6個月後牙根尖周圍反應性骨碎形維度值會比治療前下降(P=0.005)；第二組ROIs中19位患者中13位在成功根管治療6個月後牙根尖周圍反應性骨碎形維度值會比治療前下降(P=0.048)。兩組ROIs做Kappa統計量得到к=0.406和P=0.028呈現本研究方法的再現性。 總結： 鮮少研究用數值去描述反應性骨。本研究使用數學形態學與碎形維度去呈現反應性骨於根管治療前後的變化型態，結果也證實本方法的可靠性。但本研究也只是一個開端，反應性骨的真實存在形狀與治療後康復時間仍需要進一步的研究。

Objective. Mathematical morphology and box counting were used to extract trabecular pattern and to evaluate changes of reactive bone following root canal treatment. Study Design. Periapical radiographs were digitized and processed with mathematical morphology operations known as skeletonization. The trabecular patterns resulting from this skeletonization process were further analyzed with fractal dimension analysis using the box counting method. Two groups of Ragions of Interests (ROI) were selected from 19 patients for the analysis. Results. In different group, seventeen and thirteen patients showed decreased fractal dimension in the reactive bone region after clinically successful root canal treatment (RCT). Significant changes in fractal dimension, calculated by mathematical morphology operations combined with box-counting, could be noted six months after RCT (P < .05). Kappa statistic indicated significant reproducibility between the two groups of ROIs. Conclusions. Mathematical morphology combined with box counting could be a reliable and objective method for studying changes in periapical bone structure after endodontic treatment.