_nine颞下颌关节疾病课件

Unit Nine Diseases of the Temporo - mandibular Joint nThe common diseases of the temporo - mandibular joint are subluxation, dislocation and ankylosis.The infection of this joint is rare. nSubluxation半脱位 nDislocation脱位 nAnkylosis关节强直 nSubluxation. Subluxation refers to a selfreducing derangement between the components of a joint. nSelfreduce自行使复 位 nDerangement紊乱 nWhen referring to the temporo- mandibular joint, the term frequently is used to describle the situation when the condyle moves anterior to the articular eminence during opening excursion. The main symptoms are crackle, pain and limitation of jaw. The treatment is very complex. nCondyle髁状突 nArticular关节的 nEminence隆凸,隆起 nExcursion移动 nCrackle弹响 nDislocation of the temporo - mandibular joint. The temporo - mandibular joint may become dislocated as a result of external trauma, sudden or prolonged wide opening. nTrauma创伤 nPredisposing to dislocation is usually extreme capsular laxity, such as that associated with chronic subluxation, a wide opening can pull the condyle overforward to become located in front of the articular eminence, and then it can not return to the glenoid fossa. nPredispose使易罹患 nLaxity松驰 nGlenoid关节窝的 nAnkylosis of the temporo - mandibular joint.Ankylosis can be divided into two categories: false ankylosis and true ankylosis. nFalse ankylosis: False ankylosis may be due to trauma, such as gunshot wounds, with or without involvement of jaw bone, in healing of which there has been considerable formation of scar tissue either in the muscle or in the soft tissues anywhere between the upper and lower jaws. nScar tissu瘢痕组织 n Inflammation in this area may be followed by organization of exudate and formation of fibrous tissue. False ankylosis may be due to scars following extensive intraoral ulceration, nExudate渗出物 nUlceration溃疡 n the result of noma, scarlet fever or other acute exanthemas. It is frequently seen after treatment of malignant growth of the mouth by cautery, X - my and radium. nNoma坏疽性口炎 nScarlet fever猩红热 nExanthemas疹 nCautery烧灼术 nIn false ankylosis, there still nearly always be some movement present. The cause of the limitation will usually be evident on examination. The amount of resistance encountered to attempt to separate the jaws should be tested by means of wedge mouth gag inserted between the teeth. nBy means of藉 nWedge楔 nMouth gag开口器 nIn mild cases, this re- sistance may be slight and easily overcome by the mouth gag. In others, it may be impossible to produce any separation beyond a certain millimeters. nThe scar may be seen in the mucosa,skin or both of the cheek. In the gunshot and noma cases,there may be some tissue defect on the lip and cheek, the teeth are exposed to sight. If the scar is located between the maxillary tuberosity and mandibular ramus, it can not be seen or palpated. nMucosa粘膜 nDefect缺损 nMaxillary tuberosity 上颌结节 nMandibular ramus 下颌升支 nPalpate触诊 nThe extensive scar may involve the entire mucosa of the cheek; in this condition, the separation of the mandible is impossible. nTreatment. The scar bands should be cut or dissected out. The raw surface must be covered with split skin grafts, because simply cutting dense adhesion leaves a broad raw surface to granulate. nDissect解剖,切开 nGraft移植物 nAdhesion粘连 nGranulate生肉芽 n When the wound heals, it produces more scars and will contract, and the condition will not be in the least improved. If the scar extents from the cheek to the face or there is some tissue defect, nContract收缩 n the cheek and face must be repaired by a skin flap or a skin tube that were planned before the operation. nSkin flap皮瓣 nSkin tube皮管 nTrue ankylosis. True ankylosis may follow any of the suppurative conditions of the joint, resulting either from extension of infection from local structures, such as the middle ear or from metastatic septic arthritis. nSuppurative化脓性的 nMetastatic转移性的 nSeptic脓毒性的 nArthritis关节炎 nBony union of the joint surfaces and surrounding parts may also occur after severe traumatism, such as blow or fall on the chin, in which the main part of the force is received in the region of the condyle. nSevere严重的 nBlow打击 nChin颏 nForce力 nDeformity. After prolonged ankylosis, especially when dating back to early childhood before full development of the mandible, a characteristic deformity may be present. The condyloid process is shortened. nDeformity畸形 nDate back起至 nDevelopment发育 nCondyloid process 髁状突 nThis causes an apparent elongation of the coronoid process. The angle of the mandible is elongated, so that it forms a point projecting downwards, and the base of the bone under the mental foramen is thickened. nElongation伸长 nCoronoid process nMental foramen颏孔 n The mental process is much diminished in size, causing an apparent recession. The base of the bone, between the angle and a point vertically under the canine region, is deeply concave in outline. nRecession后退,凹处 nCanine region nConcave凹的 n The cause of these changes lies in the activity of the muscles that depress the jaw. The muscles of mastication, i. E, those which elevate the lower jaw are inactive, while those which assist in depressing the mandible become more and more active in an endeavor to overcome the fixation of the articulation. nBy their action the lower jaw, from the symphysis to the angle, becomes modified in proportion to the contraction of these depressor muscles Anteriorly, there are the genioglossus, the geniohyoid, the sternohyoid, nSymphysi骨的联合 nModify改变 nIn proportion to与 成比例 nGenioglossus颏舌肌 nGeniohyoid颏舌骨肌 nSternohyoid胸骨舌骨 肌 n the sternothyroid, the digastric, the omohyoid and the platysma muscles, all of which are abnormally active. Their action without the compensating factor of the mandibular motion brings about the changes noted. nSternothyroid胸骨甲 状肌 nDigastric二腹肌 nOmohyoid肩胛舌骨 肌 nPlatysma颈阔肌 nCompensate补偿,校 正 nSymptoms. Absolute immobility of the joint is rare. Even with bony fusion, it is generally possible for the incisor teeth to be slightly separated, but never more then five millimeters. If the ankylosis has taken place after the jaw has attained its full growth, visible deformity is usually absent. nSymptoms症状 nFussion融合 nIncisor teeth切牙 n If ankylosis dates from childhood, the typical deformity described above will be noted. The teeth are found to be irregular and some of them impacted, owing to lack of space for eruption. nImpacted阻生 nEruption萌出 nMany of the teeth are generally carious. A point of difficulty frequently presenting is to determine whether the ankylosis is bilateral , or if unilateral, which of the two sides is affected. nCarious龋的 n Good X - ray negatives will often be of value in clearing up these points. It has been our observation that, in a unilateral fibrous ankylosis, in attempting to open the mouth, the chin deviates to the ankylosed side . nNegative底片 nDeviate偏离,出轨 nThis is due to slight twisting motion at the damaged joint. The face on the ankylosed side is full and round and apparently normal in appearance. On the unaffected side it is flattened and deformed. nTwist扭曲,扭转 nUnaffected side健侧 nFlatten扁平 nMisinterpretation of this deformity has in many cases led to operation on the unaffected side first. The chin is more or less retracted and deviated to the ankylosed side. nMisinterpretation 误解 n