数字化根尖片平行投照定位器临床实用性探讨

目的 探讨自制数字化根尖片平行投照定位器的可靠性和实用性。方法 设计制作一套根尖片平行投照定位器，并在该定位器的X线探测器的固定板上装置一条长5mm，直径0．8mm的金属条。采用X线牙片机和ODIS-I型口腔数字成像系统对20人次拍摄20对平行投照根尖定位片。用统计学方法分析20对牙片中金属条测量值的一致性及目标牙根尖到金属条近中端的距离和角度关系的一致性。结果 等效性检验显示20对定位片的金属条测量值与金属条实际长度、直径均元差异(P＜0．05)，且两种测量方法下，金属条长度与直径和金属条近中端点与目标牙根尖的连线距离及角度等方面均无差异(P＜0．05)。结论 这套数字化根尖片平行投照定位器重复性好，可比性高，操作简单，使用方便，实用性强。

Clinical Practicality of Oral Positioner for Parallel Projection of Digital Dental Film

Objective To discuss the reliability and practicality of the self- made digital dental film oral positioner for parallel projection. Methods A set of the oral positioner for parallel projection of digital dental film were designed and made. A metal bar 5 mm in length and 0.8 mm in diameter was installed on the fixed board of the radio - detector of the positioner. In 20 individuals, we photograph twenty pairs of oral parallel projection dental positioning films by radio tooth machine and oral digital image system Type GDIS- I.The consistency in pairs of the films was statistically analysed, including the length and diameter of metal bar and the distance and angle from the target dental root tip to the nearly middle point of metal bar.Results Equivalence test showed that there were not significantly difference ( P < 0.05) between the measured value of the metal bar in the films and its real value, including the length and diameter of metal bar and the linking - line distance and angle from the target dental root tip to the nearly middle point of the metal bar. Conclusions The oral parallel projection positioner, which is of good repetitiveness, high comparability and strong practicality. When it is applied to the digital dental radiography, the positioner can be simply used conveniently in the clinical practice.