相对近距离投照法在上颌后牙应用研究  

Relatively close anode distance projection of the posterior maxillary teeth

作　　者：郭小龙[1] 王家柱[1] 石校伟[1] 王照五[1] 郭斌[1] 

机构地区：[1]中国人民解放军总医院口腔医学中心,北京100853

出　　处：《中国实用口腔科杂志》2015年第11期683-686,共4页Chinese Journal of Practical Stomatology

基　　金：解放军总医院临床科研扶持基金(2012FC-TSYS-2003)

摘　　要：目的当患者因体位受限等各种原因不能接受根尖片投照时,使用相对近距离投照技术,能够获取上颌磨牙影像,为临床诊断治疗提供依据。方法利用放大入射点空间,近光源物像放大模糊,近片物像清晰的原理,使用普通X线牙片机、5英寸×7英寸(1英寸=2.54 cm)胶片及片盒,令患者端坐,矢状面与地面垂直,头略仰,至下颌骨长轴与地面平行。片盒长轴与下颌骨长轴平行,投照面中心点紧贴欲观察的上颌磨牙根端体表部位。患者矢状面与片盒一起向被检侧倾斜约20°。X线机遮线筒口中心紧贴对侧下颌角下方1 cm处组织面,中心线经被检侧磨牙入射。结果影像可以显示上颌后牙,位于上颌窦下方、下颌磨牙区上方、颈椎影像的前方。对侧下颌升支及牙齿影像放大模糊,位于上颌后牙影像的前上区域。结论上颌后牙相对近距离投照技术,使用常规牙片X线机,临床操作简单易行,适用于各种无法开口、不能投照根尖片的患者,失败率低,影像清晰,可为临床诊断提供高质量的影像。Objective To investigate the feasibility of the relatively close anode distance projection method in situations where patients, who cannot accommodate or tolerate intraoral film placement, usually because of gagging or trismus, need a finely defined image of upper premolars and （or）molars. Methods A new projection method, based on the theory that the image of the object closer to the X-ray source is blur, while that of the object closer to the film is clearer, was used. The relatively close anode distance projection uses an intraoral dental machine combined with 5 × 7 inch films. Re- sults Images showing all premolars and molars in one quadrant simultaneously were obtained. Upper premolars and mo- lars were in the center of the image, below the ipsilateral maxillary sinus, above lower molars, posteroinferior to the mag- nified and blur contralateral posterior part of the ramus of mandible, and anterior to the cervical vertebra. Conclusion It is usually, but not always, possible to achieve a finely defined image of the upper premolars and molars with minimal distortion and no overlying bony shadows, which is especially suitable for those with limitation of mouth opening. In addi- tion, the relatively close anode distance technique is easy to master and convenient to be generalized.

关 键 词：根尖片 相对近距离 口外投照法 

分 类 号：R78[医药卫生—口腔医学]