unitnine颞下颌关节疾病

1、Unit Nine Diseases of the Temporo - mandibular JointnThe common diseases of the temporo - mandibular joint are subluxation, d i s l o c a t i o n a n d a n k y l o s i s . T h e infection of this joint is rare. nSubluxation半脱位nDislocation脱位nAnkylosis关节强直nS u b l u x a t i o n . Subluxation refers to

2、 a s e l f r e d u c i n g derangement between the components of ajoint. 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

3、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 op

4、ening. 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nLa

5、xity松驰nGlenoid关节窝的nT h r e e f o r m s o f dislocation can be distinguished, based on frequency and duration: the single acute episode, chronic recurrent and chronic persistent dislocation. Of the three,only the last two are treated surgically.nAcute episode急性发作nRecurrent复发的nAnkylosis of the temporo

6、 - 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 withoutinvolvement of jaw bone, in healing of which there has been considerable formation of scar tissue eithe

7、r in the muscle or in the soft tissues anywhere between the upper and lower jaws. nScar tissu瘢痕组织n Inflammation in thisarea 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

8、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 andradium.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

9、 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

10、 the mouth gag. In others, it may be impossible to produce any separation b e y o n d a c e r t a i n 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

11、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 themandible is imposs

12、ible. 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 wil

13、l 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 ankylosi

14、s. 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 septicarthritis. 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 sur

15、rounding 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 ofthe condyle.nSevere严重的nBlow打击nChin颏nForce力nDeformity. After prolonged ankylosis, especially when d a t i n g b a c k t o e a r l y childhood before

16、 fulldevelopment of the mandible, a characteristic deformity m a y b e p r e s e n t . T h e condyloid process is shortened. nDeformity畸形nDate back起至nDevelopment发育nCondyloid process 髁状突nThis causes an apparent e l o n g a t i o n o f t h e coronoid process. The angle of the mandible is elongated, so

17、 that it forms a point projecting downwards, and the base of the bone under the mental foramen is thickened. nElongation伸长nCoronoid processnMental foramen颏孔n The mental process is much diminished in size, causing an apparent recession. The base of the bone, between the a n g l e a n d a p o i n t ve

18、rtically under the canine region, is deeply concave in outline. nRecession后退,凹处nCanine regionnConcave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

19、depressing the mandible become more and more active in an endeavor to overcome the fixation of thearticulation. nBy their action the lower jaw, from the symphysis to the angle, becomes modified i n p r o p o r t i o n t o t h e c o n t r a c t i o n o f t h e s e depressor muscles Anteriorly, there

20、are the genioglossus, t h e g e n i o h y o i d , t h e 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 ofwhich are abnormally active. Their action without the compe

21、nsating 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 ne

22、ver 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 i

23、rregular and some of them impacted, owing to l a c k o f s p a c e f o r 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. nC

24、arious龋的n Good X - ray negatives will often be of value inclearing up these points. I t h a s b e e n o u r 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 a

25、t 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 inmany cases led to o p e r a t i o n o n t h e unaffected side first. The chin is more or less retracted and deviatedto the an