Annals ofthe Royal College oJ]Surgeons of England (1982) vol. 64

Post-traumatic disorders ofthejawjoint

J E de Burgh Norman MB ChB MDS FDSRCS FRACDS Honora!y Maxillo Facial Surgeon, Mater Misericordiac General and St George Hospitals, and HMO, Royal North Shore Hospital Sydney; Consultant to the Royal Australian Navy

Key words: TEMPOROMANDIBULARJOINT; TRAUMA; OSTEOARTHRITIS; DISLOCATION; SUBLUXATION; ANKYLOSIS; SpRGICAL TREATMENT; Summary with a constellation of symptoms here illustrated, A group of 165patients with surgical diseases ofthe tem- and are deserving ofconservative treatment. poromandibular joint treated in 3 Australian university In the 10-year period 31 st January 1971 to 31 st hospitals is reviewed. As facial trauma is relatively January 1981 more than 210 open operations on common patients have been included in the post-traumatic the jaw joint were performed by one surgeon group only ifthere was an undisputed history ofinjury re- (Table I). quinng medical or dental treatment or admission to hospital. In 38.30/o ofpatients with histologically proven TABLE I Summagy of210 operations osteoarthritis there was an undisputed histoy oftrauma. In a further group with recurrent mandibular dislocation No of No of Percentage 62.60/o were post-traumatic. Trauma was the cause of Disorder patients joints post-traumatic There is ageneral 62.5% ofcases ofmandibularankylosis. Osteoarthritis 107 122 38.3 tendency to underdiagnose degenerativejoint disease and to Mandibular ankylosis 40 59 62.5 perpetuate conservative treatment when it is crystal clear Dislocation that these measures are not being successful. It is probable (recurrent) 16 26 62.6 that intracapsularfractures ofthejawjoint arefrequently Dislocation undiagnosed and a higher index of suspicion is required. (long-standing) 2 3 100 Mandibular ankylosis continues to pose some difficulty of management and a critical review confirms that wide surgi- cal exposure ofthejoint is essential; the importance oflong- Temporomandibular ardhropathy term review is stressed. The outcome of the surgical treatment ofrecurrent luxation is excellent and an operation POST-TRAUMATIC OS1TEOARTHROPATHY ofcommendable simplicity is advocated. It was increasingly obvious to me by late 1974 that trauma was ofsingular importance in the aetiology lntroduction of a number of disorders of the jaw joint. The im- John Hunter described the articulation of the pression was reinforced by patients referred from lower jaw and temporal bone in minute detail (1). insurance companies and solicitors seeking an He recognised the functional and comparative opinion on residual disabilities. These patients re- anatomy of its 'movable cartilage' and ligaments ceived early and satisfactory treatment from my and made 'general comparison between the colleagues at other Australian centres, and in the motions ofthejaw in young and old people'. management of fracture dislocations of the jaw On the basis ofa review of 165 patients with sur- joint the policy ofboth British and Commonwealth gical diseases of the I surgeons is commendably conservative (2). have postulated that mandibular trauma may pre While not suggesting that patients suffering cipitate significant dysfunction ofeither jawjoint. trauma should be reviewed in perpetuity and It may unmask the pain dysfunction syndrome in a admitting that fracture clinics would be paralysed predisposed group (an undisputed history of if our patients were seen annually, I suggest that trauma was elicited in 12% of a series of 175 we may have been complacent in concluding that patients with this syndrome), precipitate degener- complications following fractures of the mandibu- ative changes in the capitulum, initiate sublux- lar condyle are infrequently observed and, when ation or recurrent dislocation, and in rare in- present, are usually of a minor nature provided stances result in ankylosis. It is well known that that early and adequate treatment has been insti- functional disorders of the jaw joint are common, tuted (3). I believe this view to have been espoused are frequently diagnosed in young women, present at some time by most surgeons involved in the Address tor correspondence: 9 West Street, Hurstxille, treatment ofjaw fractures (myself included) and NSW 2220, Australia now ask whether our conclucions were based on From a Hunterian Lecture delixered at the Royal College of Surgeons of England on 24th April 1981 30 J E de Burgh Nonnan

PAIN

C R E P I T U S

u) 2 0

O TALGIA 0

LOCKING I10

z oL 0-9 10-19 20-29 30-39 40-49 50-59 60-69 70-

AGE RANGE eYRS)

TOTAL NO. CASES OA.

SWELLING NO.CASES POST TRAUMATIC OA.

20 40 60 FIG. 2 Age distribution of 107 cases ofosteoarthritis (41 NO. OF CASES post-traumatic).

* TOTAL NO CASES OA.

NO. POST TRAUMATIC OA.

FIG. 1 Incidence ofsymptoms in 107 cases ofosteoarthritis (41 post-tramnatic). FEM A L E or anecdotal evidence, small samples, speculative o 30 60 90 argument (4). CLINICAL PRESENTATION (FIG. I) NO. OF CASES The predominant symptom of temporomandib- E TOTAL NOCASES OA. ular arthropathy (post-traumatic and idiopathic) O NO. CASES POST TRAUMATIC OA. in the present series was preauricular pain (with and without radiation) ofa persistent aching char- acter, often at rest but exacerbated by jaw FIG. 3 Sex incidence of 107 cases ofosteoarthnitis (41 post- movement and stress. A deep, aching otalgia in the traumatic). absence of significant aural disease was particu- my thesis that they may be the cause ofsubsequent larly common and frequently resulted in primary osteoarthritis. We recognise the delicate architec- referral to an otolaryngologist. Crepitus, varying ture ofthe capitulum and believe that silent intra- from fine crepitation to a coarse, staccato crunch, capsular fractures are more frequently than not was always discernible by ausculation and invari- associated with the obvious subsigmoid fracture. ably associated with pain. Considering that the traumatising force is trans- Irrespective ofaetiology advanced osteoarthritis mitted undiminished in all directions (5,6), it is was always accompanied by a coarse grating and clear that the capitulum may be violently forced constant aching. Some patients complained of into the mandibular fossa and under some early morning stiffness and restriction of circumstances its plateau crushed before a fracture movement; as the day progressed there was in- occurs in the surgical neck. This thesis is not creasing freedom of movement. Intermittent lock- unsupported. Our unit has received a number of ing was described and was invariably cleared by a secondary referrals in which the patient had trick movement. It was not possible to identify and sustained an anteromedial fracture-dislocation of isolate the post-traumatic cases purely on the basis the condylar neck which was treated by of symptomatology. Figures 2 and 3 show the age conventional closed reduction and intermaxillary and sex incidence in 107 patients with osteo- fixation. A degree of and open bite arthritis and indicate the frequency of post- had developed which was still present after traumatic cases among male patients. removal of fxation. Joint exploration was advised INTRACAPSULAR FRACTURES and old intracapsular fractures were clearly I propose that intracapsular fractures are fre- demonstrated in addition to the obvious fracture of quently undiagnosed at the time ofinjury and it is the surgical neck. Significant degenerative Post-traumatic disorders ofthejawjoint 31 changes were microscopically obvious, with the presence of exuberant areas of lateral callus. The Bunctional and occlusal results ofthe procedures in these 6 patients were excellent. 50L In these patients with intracapsular fractures of the condyle diagnosed retrospectively the histories were surprisingly consistent. Each reported pre- 40I auricular swelling (an effusion, although not 0to diagnosed as such), jaw stiffness, pain, and U inability to masticate for upwards of 3 or 4 weeks after the accident. Plain radiographs taken at that 0 30~ time were reviewed if available and varied in Lu quality from indifferent to excellent; since some of 0 the patients had suffered multiple injuries and ro 201. peripheral fractures this is hardly surprising. In no case was an intracapsular fracture diagnosed, z taken months later showed I although films 12-36 I C I advanced osteoarthritis. Our research suggests that intracapsular and crush fractures of the capitulum may be a signifi- 0 cant cause of post-traumatic osteoarthritis :1 11 III IV NAD. productive of continuing pain and disability unresponsive to conservative treatment and ulti- G R A D E mately requiringjoint replacement. E TOTAL NO.CASES OA. HISTOPATHOLOGY OF TEMPOROMANDIBULAR OSTEOARTHRITIS In the 10-year period under review 122 condyles E NO CASES POST TRAUMATIC OA. removed at operation were submitted for histopathological examination. A review of the FIG. 4 Histopathological grading of 122 mandibular entire series was carried out by a single condyles (after Toller (9) and Blackwood (10)). histo.pathologist who had no recourse at any stage to clinical data or to assessments carried out by and 1 in Stage III-IV, while 1 condyle showed no previous pathologists. Cases found on review to be abnormality. Additional findings were recorded as examples of condylar were excluded the pathologist was not aware whether the osteo- from the series and a report on them published arthritis resulted from trauma. Accordingly it was elsewhere (7). Also excluded were examples of noted in 58 instances that as well as the criteria for osteochondroma of the mandibular condyle and condylar osteoarthritis there was active lateral or one case of invasion of the condyle by relatively central new bone formation consistent with recent well-differentiated squamous carcinoma arising in fracture callus or dense focal sclerosis suggestive of adjacent tissues. Cases in which orientation of the old inactive callus. This group was subjected to specimen precluded examination of the articular further scrutiny. In 21 of the 58 cases (36.2%) surface and subjacent bone were also deleted from there was an undisputed history oftrauma and in a the series. further 5 cases (8.6%), all in women, trauma was All condyles examined since January 1977 have suspected but not admitted. There was thus been bisected coronally after slow decalcification definite or probable trauma in 44.8% of the 58 so that the maximum available articular and bone cases. In 7 cases there were articular fibrous tags surface can be visualised. This is particularly im- and fibrocollagenous tufts arising from the sub- portant in the assessment of the depth to which articular cortex suggestive ofadhesions and hence entrapment' ofcartilage occurs in cases ofcondyl- of clinical fibrous ankylosis. An unusual mosaic ar hyperplasia. It is also ofgreat value in estimat- pattern of woven bone resembling Paget's disease ing marrow and deep-seated sclerotic foci or bone being actively remodelled rather than a suggestive of old callus in cases in which osteo- healing fracture was found in 13 cases. The osteo- arthritis is present. blastic and osteoclastic activity in these areas, With due acknowledgement ofthe most import- which were often focal, varied from extreme to ant work of Professor H J J Blackwood the minimal and was not graded in any way. All such condyles were grouped according to the appearances were recorded as 'mosaic'. A further 9 classification of Toller as Stage I, II, III, or IV patients (11 condyles) were excluded from the (8-10) (Fig. 4). By this method 51 condyles were series as the clinical or pathological records were classified in Stage I, 31 in Stage II, 38 in Stage III, incomplete. This was unfortunate as 5 were post- 32 J E di Burgh Norman

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TOTAL "O OF JOINTS (OA

* POST NOAUMAriC ((A)

FIG. 6 Analysis of 122 operations (mandibular condyl- ectomy and Silastic arthroplasty).

removed in each case and histological examination confirmed the clinical diagnosis. There was a wide range of duration of symptoms, from 9 months to 30 years, with a mean for the series of 2.7 years. The patients had all reported facial pain of articu1ar origin (previously described) unrespon- sive to skilled and exhaustive conservative measures at general practitioner, specialist, and professorial level. These measures are familiar to all and included occlusal analysis, equilibration and restitution with full, partial, and fixed prostheses, splint therapy, physiotherapy, re- medial exercises, psychotherapy, manipulative therapy under general anaesthesia in conjunction with intra-articular steroids (11), anti-inflam- matory , and acupuncture. Thirteen patients underwent bilateral operations and we noted with interest that Banks and MacKenzie (12) in their important paper on mandibular con- FIG. 5 Post-traumatic osteoarthritis of the mandibular dylotomy concluded that 'it is clear that sympto- condyle (Stage III). (a) Male19years. (b)Aale 26years. matic improvement is good although bilateral (c) Female 21years. cases were less successful than unilateral'. traumatic. The appearances illustrated in Figure 5 are typical ofStage-III changes. Mandibular dislocation RESULTS AND ANALYSIS OF OPERATION Anterior mandibular dislocation (13) is classified The subjective results of 122 operations (mandib- as acute, chronic recurrent, and long-standing. It ular condylectomy and Silastic arthroplasty) are is clear that trauma is involved in most acute and shown in tabular form in Figure 6; 50% of the chronic forms ofanterior dislocation, whereas sub- patients were cured by operation and 27% signifi- luiation may be post-traumatic or the legacy ofthe cantly improved, 8% reported some improvement, pain dysfunction syndrome. Of my series of 16 pa- and 15% were no better. The longest period of tients referred with chronic recurrent dislocation follow-up was 8 years, the shortest 4 months, and or severe subluxation of one or both joints 10 the mean 4 years. In the groups with little or no im- (63%) gave an undisputed history of causative provement 7 patients had received psychiatric trauma. treatment for a significant depressive illness; one Recurrent dislocation in our unit is managed by patient developed Sjogren's syndrome, another a modification of the Dautrey -Le Clerc and , and a further 2 chronic Girard procedure (14-17). We initially employed lymphatic leukaemia. Chronic submandibular the technique of the late Professor Alfred sialadenitis was diagnosed in addition to osteo- Rehrmann (18), and although not described in his arthritis in 2 patients; the was paper we reinforced the lateral check ligament Post-traumatic disorders ofthejawjoint 33 with a rotation flap of temporalis fascia. In poorly One man cured of recurrent dislocation developed controlled epileptic and subnormal patients intermittent pain in onejawjoint and was the only recurrent dislocation is most suitably treated by patient not entirely satisfied with the result. The condylectomy. To spare the patient an operation longest period of follow-up was 6 years and 8 upon the ilium or mastoid we have, over the months, the shortest 3 months, and the mean 24.6 quinquennium, developed a procedure which is months. This is a highly satisfactory operation of curative and involves hospital admission for only 7 commendable simplicity productive of excellent days. Numerous operative techniques have been results and minimal morbidity. advocated to gain access to the temporomandibu- LONG-STANDING DISLOCATION lar joint and most recently an elegant approach Three patients were referred with an undiagnosed with a defined anatomical basis has been described and long-standing dislocation present for 24 by Al-Kayat and Bramley (19). We have found the months, 7 months, and 4 years respectively. following procedure satisfactory. Closed reduction failed in the first patient and con- After infiltration with POR8 and Hyalase, dylectomy was carried out. In the second and third which has a profound haemostatic effect on the tis- cases an open reduction was achieved through sues, the jaw joint is widely exposed through a submandibular incisions and thejaw reduced with modified preauricular incision. The preliminary traction wires and considerable difficulty. muscle-splitting incision allows wide exposure of the lateral surface of the temporal squama and permits relaxed anterior dissection at the subperi- Mandibular ankylosis osteal level without traction on the . CLINICAL MATERIAL The glenoid lobe of the is swept A clinical study has been made of40 patients with forward with a Dickson-Wright dissector and the mandibular ankylosis affecting 59 joints. Few joint capsule and articular eminence demon- patients presented with ankylosis as a sequel ofthe strated. The lateral ligament and capsule (20) are infectious of childhood or birth trauma, re- detached from the zygomatic tubercle and lateral flecting the better nutrition, availability ofantibio- margin of the glenoid fossa. An oblique osteotomy tics, and higher standards ofmedical, surgical, and of the zygomatic arch and the articular eminence obstetric care which exist today in Australia. The at the level of the articular tubercle allows the aetiological distribution is shown in Table II. lateral half of the eminence to be down-fractured. Organisation of the haematoma about a medial It is important that the osteotomy be carried into fracture-dislocation of the condyle at the subsig- the mandibular fossae and the medial extent ofthis moid level was the most common cause and result- cut is predetermnined by a vertical eminotomy com- ed in bilateral ankylosis in 10 patients and uni- menced via the temporal fossa and completed lateral ankylosis in a further 15. The injury was through the mandibular fossa. The resultant de- caused by birth trauma in 1 case, a fall in 6, a fect is partially obturated with a Silastic rod stabil- motor vehicle accident in 17, and a diving accident ised by a wire osteosynthesis. We consider it in 1. important not to fill the defect completely with a Trauma was the cause of ankylosis in 62.5% of which acts as a Silastic wedge and prefer the rod, our cases, whereas in the series reported by stable spacer until the dehiscence organises. The lateral ligament is plicated and reinforced with a hammered patch graft of temporalis fascia. The I'ABLE 1I Mandibular ankylosis: aetiology of40 cases wound is closed in layers with suction drainage. The importance ofa puree diet for 5 weeks after the No % operation is explained and advice given by the Cause dietitian. If there is doubt as to anticipated co- Birth trauma 1 62.5 operation intermaxillary fixation is applied. Other trauma 24 Suppurative arthropathy 6 15 RESULTS Postoperative 2 5 Of the 16 patients referred with chronic recurrent Rheumatoid arthritis 1 2.5 dislocation or severe subluxation of one or both Ankylosing spondylitis + HC 1 2.5 jawjoints 2 were treated by a modification ofRehr- Psoriatic arthropathy + HC 1 2.5 mann's procedure and 14 by the operation descri- Radiotherapy ('frozen joint') 2 5 bed. In these 16 patients 26jawjoints were involv- Tumour (osteochondroma) 1 2.5 1 2.5 ed and an undisputed history of trauma was Idiopathic all obtained in 10 cases (62.6%/). At review HC = multiple injections of hydrocortisone by patient's patients achieved a gape of 2.75-3.75 cm, a satis- factory range oflowerjaw movements was demon- physician. strated, and none complained of further luxation. 34 J E de Burgh Norman Dufourmental and Darcissac (21) 41% of the able preparatory to operation and helps the sur- ankyloses were the result of and 30% geon make an accurate assessment ofthe extent of post-traumatic. the ankylosis. RADIOGRAPHY Irrespective of aetiology (traumatic or suppu- Although plain radiograyphy is helpful, tomo- rative), the joint space may be present or oblit- graphy in both coronal and sagittal planes is desir- erated in a simple or intracapsular ankylosis. If

d euEE Mandibular dislocation (a-d) and ankyloses (e-fl: operatve details and appearances: a) Temporalis musde is split with cutting diathermy. b) Exposure oflateral temporomandibular ligament andjoint capsuk. c) Lateral temporomandibular ligament is detachedfrom the lateral oftheglenoidfossa and articular eminence. d) Silastic strut maintaining thegapfollowingglenoid hemiemintomy. Note wire osteosynthesis. e) Osteochondroma ofleft mandibular condyle with.ankylosis to temporal bone (female, 71years). J) Long-standingpost-traumatic osseus ankylosis ofthe nd temporal bone (female, 12years). Post-traumatic disorders oJ thejawjoint 35 present it will be visible in both projections as a and the 10-cm temporal extension provides this. Fine, convex, radiotranslucent line between caput The temporalis muscle is split with cutting dia- and temporal bone. In some cases exuberant bone thermy along the length ofthe incision and cleanly will extend from the lateral aspect ofthe mandible lifted from the temporal squama. Forward to the zygomatic arch. The sagittal tomogram may dissection at the subperiosteal level safeguards the in addition show a mushroom deformity of the facial nerve and neurapraxia is improbable. Intra- condyle with a decrease in height of the condylar capsular ankyloses are cured by condylectomy and neck. The latter is a legacy oftelescoping ofthe sur- Silastic arthroplasty. Secondary hypertrophy of gical neck and the former oforganisation and ossi- the coronoid process is relatively common in long- fication of the intracapsular haematoma and is standing ankylosis, and where the coronoid characteristic of simple post-traumatic ankylosis process is 3-4 cm long and invested in a tenacious in the aduLt. The peroperative findings are fashion by the tendinous insertion of the tempor- illustrated in the colour plate. alis muscle zygomatic osteotomy may be required Extracapsular ankyloses appear to be oftwo dis- to provide access. We consider the quantity of tinct types. In the first the mandibular ramus and bone removed during osteoarthrectomy ofgreater coronoid process are present with discernible importance than the material used for arthro- architecture. The coronoid process may be plasty, although we have experience of both the enlarged and elongated, providing some indi- Dow Corning and Bowerman-Conroy prostheses cation of the length of history of immobility. A and the costochondral graft. I should record that I mass of bone extending from the auditory meatus have removed 4 costochondral grafts inserted at to articular eminence and ramus obscures the con- other centres by surgeons of greater competence dyle. An exostosis ofthe mandibular angle is noted than myself. in long-standing cases and may accompany ante- Our unit has been fortunate in avoiding most of gonial notching. In the second and more the known complications and I allude briefly only exuberant and florid form there is loss of anatom- to peroperative bleeding. It is unlikely that the in- ical features and the ramus is represented by a ternal maxillary artery will be inadvertently broad block of bone of uniform radiodensity divided by the experienced surgeon, but. if this flowing uninterrupted to the skull base. The occurs the situation is retrieved by securing the coronal tomogram shows the ramus to be marked- vessel with a Weck clip. The mandibular vessels ly thickened with diminution in size of the ptery- are also vulnerable. Venous bleeding from the goid space. Massive ankylosis is occasionally in- pterygoid plexus may be persistent and if careful terrupted by a radiotranslucent zone at its upper search fails to reveal the source firm packing ofthe end and the surgeon might mistakenly diagnose a wound will give respite. Should this venous plane of cleavage. He should not be surpris'ed to bleeding be uncontrolled at the end of the oper- find at operation that this 'plane' lies on the medial ation the surgeon will not hesitate to leave in the aspect of-the ramus and is only uncovered after 2 or wound a 1-in (2.5-cm) ribbon gauze pack impreg- 3 cm ofdense cortical bone has been resected. An nated with BIPP. The tail of the pack is led out examination of historical specimens (Table III) through a stab incision. Venous bleeding from the confirms the observations regarding a radio- circulus vasculosus is contained by oversuturing. graphic joint space. The two varieties ofankylosis POSTOPERATIVE CARE exhibit features common to all aetiologies and Early, sustained, and supervised movement in the confirm the value of revisiting the museum postoperative period is a sine qua non, and a specimens donated and described by our pioneer bundle of tongue spatulae is used progressively to colleagues. increase and maintain mouth opening to 3 cm. We routinely carry out a manipulation under anaes- I.IABL: II I Mandibular ankylosis: histoncal specimens in London museums thesia in the second week after operation. Monthly Author Date Museum Sex Age Aetioog;y review is imperative in the first year and failure to supervise the review personally has been the cause Howship 1816 Royal College M 56 Suppurative offailure in at least 2 cases. Although tempting to ofSurgeons (:ooper c. 1840 University College F 30 Traumatic apportion blame between distance and disinterest, Hoseital I am convinced that ifreankylosis is to be avoided Hilton 1863 Guy s M NK Traumatic the patient must be reviewed by the surgeon. Ifat Heath 1884 St Bartholomew's NK NK Suppurative review it is noted that the number of tongue NK = not known spatulae is decreasing the patient is readmitted to hospital on a day-care basis for manipulation OPERATION (SEE COLOUR PLATE) under anaesthesia. In extensive bony ankylosis a more generous Appreciation and thanks are due to Professor Paul incision is required than that previously described Bramley for advice and constructive criticism in the 36 J E de Burgh ANorman preparation of this paper. Thanks are due to my 11 Toller PA. Use and misuse of intra-articular corti- pathologist, Dr Dorothy Painter, and her technical staff costeroids in treatment oftemporomandibular joint at the Mater Misericordiae General Hospital. Other col- pain. Proceedings of the Royal Society of Medicine leagues and friends knowing my interest have most 1977;70:461-3. generously referred their patients or contributed and 12 Banks P, MacKenzie I. Condylotomy.J Maxillofac assisted in other ways and their counsel and kindness is Surg 1975;3:170-81. acknowledged with the greatest pleasure. 13 Cooper Sir A. A treatise on dislocations and on frac- tures of the joints. London: Longman, Hurst, Rees, References Orme, Brown, 1822:386-94. I Hunter J. Treatise on the natural history and 14 DautreyJ, Pepersack W. Temporomandibularjoint disease of the human teeth explaining their . Abstracts 3rd Congress EAMFS. London structure, use, formation, growth and disease (1771 6-11 Sept. 1976:172. and 1778). Philadelphia: Haswell, Barrington, and 15 Leclerc G-C, Girard C. Un nouveau procede de Haswell, 1839. butee dans le traitement chirurgical de la luxation 2 MacLennan WD. Fractures of mandibular recidivante de la marchoire inferieure. Memoires de condylar process. BrJ Oral Surg 1969;8:31-9. I'Academie de Chirurgie 1943;69:457-9. 3 Rowe NL, Killey HC. Fractures of the facial skel- 16 Schade G. Surgical treatment ofhabitual luxation of eton. 2nd ed. Edinburgh: Livingstone, 1968. the temporomandibular joint. J Maxillofac Surg 4 Ward TG. Surgery of the mandibular joint. Ann R 1977;5: 146-50. Coll Surg Engl 1961;28:139-52. 17 Poswillo D. Surgery of the temporomandibular 5 da Fonseca GD. Experimental study on fractures of joint. In: Zart GA, Carlsson G, eds. Temporo- mandibular condylar process. IntJ Oral Surg 1974; mandibular joint function and dysfunction. 3:89-101. Copenhagen: Munksgaard, 1979. 6 Huelke DF, HargerJH. Maxillofacial injuries: their 18 Rehrmann A, KreidlerJ. Late results after arthro- nature and mechanisms of production. J Oral Surg eresis of the temporomandibular joint by auto- 1969;27:451-60. plastic bone graft.JI Maxillofac Surg 1973;1 :99-103. 7 Norman JEdeB, Painter DA. Hyperplasia of the 19 Al-Kayat A, Bramley PA. A modified preauricular mandibular condyle. J Maxillofac Surg 1980;8: approach to the temporomandibular joint and 161-75. malar arch. BrJ Oral Surg 1979;17:91-103. 8 Toller PA. Osteoarthrosis of the mandibular con- 20 Griffin CJ, Hawthorn R, Harris R. Anatomy and dyle. Br DentJ 1973;134:223-31. histology of the human temporomandibular joint. 9 Toller PA. Temporomandibular arthropathy. Monogr Oral Sci 1975;4:1-26. Proceedings of the Royal Society of Medicine 1974; 21 Dufourmental L. Notes sur cent cas d'ankylose 67:153-9. temporo-maxillaire operes. Bulletins et Memoires 10 Blackwood HJJ. Arthritis of the mandibular joint. de la Soci&e des Chirurgiens de Paris 1935;27(6): Br DentJ 1963;1 15:317-26. 149-61.