根尖片评估单根牙骨内牙根表面积的准确性

Preliminary study on the accuracy of infrabony root surface area of single-root teeth by periapical films

目的:针对不同骨吸收类型的牙周炎患牙,探索根尖片评估单根牙骨内牙根表面积的准确性。方法:回顾性分析2014年1月到2016年12月就诊于北京大学口腔医院牙周科门诊患者的病历资料和影像学资料,将纳入的患牙分为水平骨吸收组和角形骨吸收组,在锥形束CT(cone beam computed tomography,CBCT)数据中提取牙齿三维数字模型,并测量计算骨内牙根表面积的百分比,在根尖片影像资料中测量计算剩余牙槽骨高度百分比,对两者的关联性进行分析,并比较各组中两者的差异。结果:共纳入患者32名,其中男25例,女7例,年龄26~60岁;单根患牙79颗,其中水平骨吸收患牙41颗,角形骨吸收患牙38颗,根尖片显示剩余牙槽骨高度百分比在45.13%~90.39%,相应CBCT显示骨内牙根表面积百分比在36.27%~93.03%。水平骨吸收组根尖片显示的剩余牙槽骨高度百分比不服从正态分布,对剩余牙槽骨高度百分比和骨内牙根表面积百分比使用两配对样本Wilcoxon符号秩和检验,渐进显著性P=0.382,显示两者的差异无统计学意义,两者差值的均值为0,95%的一致性界限为-9.7%~9.8%,在一致性限度专业界值-15%~15%内;角形骨吸收组剩余牙槽骨高度百分比和骨内牙根表面积百分比均呈正态分布,对两组数据进行配对t检验,发现两者差异有统计学意义(P<0.001),两者差值的均值为7.2%,95%置信区间为-13.1%~27.5%,在一致性限度专业界值-15%~15%之外。结论:对于水平型骨吸收者,根尖片揭示的近远中剩余牙槽骨高度可以反映骨内牙根表面积;而对于角形骨吸收者,根尖片难以准确反映牙周组织破坏情况,且往往会低估破坏的程度,必要时应加拍CBCT以明确其病损程度。

Objective ： To explore the accuracy o f p e r ia pica l f i lm in evaluating the infrabone root sur-face area of single-root teeth wi th dif fe re nt types o f resorption o f the alveolar bone. Methods ： In this study, the medical records and imaging data o f patients in Department o f Periodontology o f Peking U n ive r-sity Hospital of Stomatology from January 2014 to December 2016 were retrospectively analysed. The in -volved teeth were divided into two g ro up s： horizontal bone loss group and ve r t ica l bone loss group. D ig ita l three-dimensional models of teeth were segmented from cone beam computed tomography （CBC T） d a ta, and the percentage of the infrabone root surface area was measured. W h i le the percentage o f the residual alveolar bone was measured on the p e r ia pica l f i lms . The correlat ion o f the two percentages were analyzed, and the differences between the two percentages o f each group were compared. Results ： T h ir ty - tw o pa-tients and 79 single-root teeth were involved to ta l ly , in whom there were 25 men and 7 women, aged 26 -60 years, and of which there were 41 teeth in the horizontal bone loss group and 38 teeth in the ver-tical bone loss group. The remaining alveolar bone height percentages were 45. 13% - 90. 3 9 % on the periapical films , and at the same t ime , the infrabone root surface area percentages were 36. 2 7 % - 93.03% on CBCT. The residual alveolar bone height percentage o f the horizontal bone loss group was not subject to normal dist ribut ion , so the residual alveolar bone height percentage and the infrabone root sur-face area percentage were analyzed by Wilcoxon matched p a ir rank test （ P = 0. 382 ） , and the result showed no statistically signif icant diffe re nce. The mean value o f difference value o f the two measurements was 0, and the consistency l imi t o f 95 % was - 9 . 7 % -9.8%,between the c l in ic a l consistency l im i t （-15% -15%）. The residual alveolar bone height percentage and the infrabone root surface area per-centage of the vert ical bone loss group were analyzed by paired T test （P 〈 0. 001 ）,and the result showed statistically signif icant diffe re nce. The mean value o f difference value o f the two measurements was 7.2%, and the consistency l imi t o f 9 5 % was -13. 1 % - 27. 5% , beyond c l in ic a l consistency l i -mit （-15% -15%）. Conclusion; For the teeth w ith horizontal bone loss, the proximal residual alveo-lar bone height reflected on the pe ria pica l f i lms could show the infrabone root surface area relat ive ly accu-rately. For the teeth with ver t ical bone lo s s, the pe ria pica l f i lm s could not show the degree o f periodontal tissue loss accurately, and i t would underestimate the extent o f bone destruction u s u a l ly, so CBCT might be taken to show the bone destruction condition o f this type o f teeth i f necessary.