英语论文网

ng interference tends to become exaggerated by attritional wear. The broad inner aspects of the supposting wsps tend to create large wear facets, which cause teeth to be in closer intimate contact, and the resulting interference is not only perpetuated but also accentuated. Furthermore, attrition caused by an abrasive medium, such as foods, tends to occur more rapidly on the working side. This in turn causes a gradual increase in the amount of contact on the nonworking side.
4. Nonworking interferences traverse diagonally across the tooth at the area of greatest leverage creating a great deal of interocclusal friction. This is commonly referred to as grasping contact. Grasping contact tends to displace the lower teeth out of their normal alignment in the arch. Although most horizontal contacting interference tend to condense lower teeth into their normal splinted arrangement in the arch, the nonworking interterence lifts the lower teeth out of their normal splinted arrangement creating a potentially destructive horizontal load. The upper arch appears to be equally afflicted by all horizontals contacting interference.
Studies that have been performed on the prevalence of nonworking interference in molar teeth with severe periodontal disease indicate that there is a greater incidence of nonworking interferences present in areas of advanced periodontal destruction. Although it is difficult to prove a true cause-effect relationship, the clinical experience of the author supports this correlation.
5. It has bee clearly demonstrated that myofascial pain dysfunction syndrome has multiple causes and the occlusal interference is only a contributory cause. However, when interference is a causative agent in MPD syndrome, it is commonly held that the monworking interference tends to be extremely active as an occlusal irritant in the symptom process. The explanation that is frequently offered if that when the teeth on the working side are unable to come together because of a nonworking interference, strain is placed on the lateral temporomandibular ligament of the working condyle because the working condyle is in a superior position on the glenoid eminence and is suspended by the distension of the temporomandibular ligament. In order for the teeth to come together on the working side, the condyle would have to be displaced more cranially. This could occur only if the ligament were severly distorted. The theory holds that if a ligament is displaced in a direction that may cause it to e injured a splinting reflex is manifested by a spasm in the muscles associated with the working side of the mouth.
It is therefore not uncommon to find a slight correlation between a nonworking interference and a spasm on the opposite side of the it should be re-emphasized that occlusal interference is only one aspect of the causative factors of MPD syndrome and therefore adjustment of a nonworking interference should be considered a part of MPD therapy only after careful evaluation.
VOCABULARY
l. occlusal adjustment 调合
2. occlusal arrangement 合关系
3. masticatory system 咀嚼关系
4. objective 客观的，真实的；目标，显微镜目镜
5. occlusal correction 调整
6. axial loading 轴向负荷
7. vertical force 垂直向力
8. intercuspal positon (IC) w 牙尖嵌合位
9. terminal hinge arc 末端铰链弧
10. closure 关闭，闭口
11. reproducibility 可重复性，可复制性
12. clinician 临床医师
13. retruded contaction position 后退接触位
14. opposing te