Functional rehabilitation of ankylosed temporomandibular joints

Functional rehabilitation of ankylosed temporomandibular joints Raja Kummoona, B.D.S., F.D.S.R.C.S.(Eng.), COLLEGE OF DENTISTRY,

BAGHDAD

F.I.C.D.,*

Baghdad, Iraq

UNIVERSITY

Successfulchrome-cobaltprostheseshave been used to replace the condyle and glenoid fossa in six young Macacu irus monkeys. In one group of two animals the left temporomandibularjoint was replaced; in the secondgroup the right joint and in the third group both temporomandibularjoints were replaced. Neither masticatory function nor ability to open or close the mouth was affected, and all the animals remained in excellent health, living in the colony for 9 to 10 months. A similar surgical procedure was carried out for treatment of three human patients with ankylosed temporomandibularjoints.

I n ancient Egypt fixation of the jaw joint was a well-known disease.Hunter,’ in 1778,

was among the first to explore the possibility of scientific managementof ankylosis of humanjoints. In 1854Esmarch2describedthe operation of gap ostectomy to mobilize the ankylosed mandible, although Rhea Barton3 in 1826, had previously proposedthe concept of pseudoarthrosis.Humphery4performed his.first condylectomy in 1856, but during the early part of this century much knowledge was obtained through the work of Blair,’ Risdon6 and Kazanjian’ with respect to the relief of ankylosis of the jaw joints. In correcting the problem, Dingmar?’ and Wakeleys advised the use of a flap of temporal fascia interposed in the gap after excision of the condyle. In 1974 Converse” suggestedthe use of a temporal muscle flap, while Poswillo” suggestedthat a costochondral graft be used. Prior to the routine use of costochondralgrafts, many of the techniques for relief of ankylosis failed becauseof either faulty technique or subsequentossification or chondrification of the interposed tissues. Etiology

and

clinical

features

Damageto the temporomandibularjoint as a result of trauma or infection in childhood may predisposeto ankylosis. However, trauma is probably the most important factor in the development of ankylosis. This may present as a unilateral or bilateral finding, with bony or fibrous ankylosis. An analysisof sixty casesof temporomandibularjoint ankylosis *Assistant Professorof Oral and Maxillo-Facial Surgery.

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Fig. 1. A diagram

representing

the total replacement

of the temporomandibular

joint by a metal prosthesis.

revealed that forty-two (70 per cent) were due to traumatic episodes and 18 per cent were due to infection. One patient had chronic middle ear disease, and two had unilateral hip ankylosis. The male-to-female ratio was about 1: 1. Limitation of movement produces growth disorders in the middle and lower thirds of the face, with progressive asymmetry as the affected parts fail to respond to the demand of the expanding functional periosteal matrix governing growth. Because of the limited movement and facial deformity, diet may be restricted, speech and appearance are impaired, respiratory diseases may be initiated, and behavioral deficits may arise. MATERIALS AND METHODS Design of the temporomandibular

joint prosthesis.

The total replacement of the temporomandibular joint should be feasible, since total hip replacement has become a well-accepted procedure following the pioneer work of British surgeons, notably Charnley and MacKee. Prosthetic replacement of the temporomandibular joint has previously been described by Christensen” in 1963 and by Kent and associatesr3 in 1975. In this research the prosthesis designed to replace the temporomandibular joint consisted of two parts to satisfy the requirements of a functional artificial joint replacing both compartments of the joint. The condylar part consisted of a head, which was more or less a copy of the natural condyle, together with an intramedullary perforated stem or shaft for transferring the load to the mandible. This arm was inserted sagittally in the cancellous bone of the ascending ramus in the axial line. The other part of the prosthesis was designed to replace the glenoid fossa and the lateral border of the zygomatic arch plus the

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Fig. 2. Ten months after total replacement of a temporomandibular joint with a chrome cobalt prosthesis in Macuca irus monkey. Note normal opening of the mouth, with no deviation.

a

extension of a small arm to cover the zygomatic process of the temporal bone. One or two holes were provided for fixation. Fixation of the prosthesis was achieved by using a surgical bone cement of autopolymerizing methacrylate on the condylar part, in order to provide the most intimate fit possible between the implant and bone. The cement also reduced the stress concentration and transferred the load of mastication from the metallic shaft of the prosthesis uniformly to the cancellous bone of the ascending ramus. Screws or wires were used for fixation of the upper part of the prosthesis to the zygomatic root of the temporal bone. The head of the condyle was designed to be slightly flat and to articulate with a flattened glenoid fossa, thus allowing fibrous tissue penetration from the capsular wall of the joint (Fig. 1). Experimental

study

Six female adult Macaca irus monkeys with intact dentitions, 7 years of age and approximately the same weight, were divided into three groups of two animals each, all of which had undergone condylectomy and meniscectomy some 3 months previously. Surgical procedures were performed either under gas-oxygen-halothane anesthesia, or with ketamine hydrochloride (Vetalar) sedation plus the infiltration of a local analgesic agent in the temporomandibular joint area. A precast chromium-cobalt alloy prosthesis was fixed in place after excision of the condyle and meniscus via a preauricular incision. The condylar part was fixed by using Surgical Simplex bone cement (Howmedica Company), after a trough or channel was made through the cancellous bone between the medial and lateral cortical plates of the ascending ramus along the long axis. This channel was 1 cm. deep and 2 mm. wide. The upper prosthesis was fixed by stainless steel wires.

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Fig. 3. Postmortem radiograph of half of the face of a Mucaca irus monkey. The implant has been in place 10 months.

In the first group the left side was replaced, in the second group the right side was replaced, and in the third group both sides were replaced. After recovery from anesthesia, all animals were returned to normal cage life with a normal diet and antibiotic coverage with Triplopen every second day for one week. RESULTS Neither masticatory function nor ability to open or close the mouth was affected to any recognizable extent in any of these animals. All monkeys remained in excellent health, living in the colony for 9 to 10 months (Fig. 2). One left, one right, and one bilateral replacement were considered to be successful. In the others the condylar part was displaced out of the channel resulting in the condylar shaft being shortened. Even with the displacement of the prosthesis observed on the final radiographs, there was little or no effect on the function or occlusion of the teeth. Radiographs were made routinely before and during the experiment at monthly intervals until all of the animals were killed in 10 months. Normal occlusion of the teeth was maintained in all animals, with no deviation of the jaw to the operated side in unilateral cases or open-bite in bilateral cases. Postmortem clinical and radiologic examinations revealed the presence of adequate functional joints following total replacement with a two-part chrome-cobalt prosthesis (Fig. 3). Macroscopic

examination

Macroscopic examination of the replaced temporomandibular joint revealed the presence of a dense capsular tissue with a smooth surface adjacent to the condylar head. The top of the condylar prosthesis was covered by a thin layer of fibrous tissue less than 0.5

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Fig. 4. Dissection of M. irus monkey showing the fibrous tissue layer (FT) between the top (TP) and lower (LP) prostheses in the position of the intra-articular disc.

Fii. 5. a, Section through the ascending ramus adjacent to the implant showing a network of healthy granulation tissue (CT) and fibrous tissue associated with bone cement (EC) and implant (I). The section also shows well-organized granulation tissue (GT) and well-oriented collagen fibers (CF) beneath the implant (I). (Hematoxylin and eosin stain. Magnification, X 80.) b, Detail demonstrating that the collagen fibers (CF) run parallel to the direction of the implant (I). (Hematoxylin and eosin stain. Magnification, x 320.)

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Fig. 6. Section through the glenoid fossa which demonstrates that compact bone and marrow spaces beneath the implant are vital. The implant (I) is covered by a thin layer of fibrous tissue (FTJ. (Hematoxylin and eosin stain. Magnification, x220.) Fig. 7. Microradiograph of a ground section of the TMJ prosthesis in situ showing the relationship of the implant (I) to the bone of the glenoid fossa above top prosthesis (I?) and the ascending ramus below lower prosthesis (LP),

mm. in thickness. The metal was clean and showed no corrosive or color changes. Between the two prostheses, there was a fibrous tissue layer approximately 2 mm. in thickness, in the position of the intra-articular disc. This tissue apparently originated from the capsular wall and covered the interface between the two metallic surfaces of the prosthesis (Fig. 4). Microscopic

examination

The tissue and cellular reaction to the total replacement of the temporomandibular joint was studied by analysis of the decalcified sections. Although ground sections were also prepared, they provided less information regarding cellular detail. The nature of the fibrous tissue associated with the bone cement and condylar part. There was a minimum of inflammatory cells, with no evidence of infection, although there were well-organized granulation tissue and very well-orientated collagen fibers with fibrous tissue beneath. It appeared that the reaction to the bone cement and metal was good. The collagen fibers were seen to run parallel to the direction of the implant. The bone in the surrounding area was vital and healthy, and in some areas a network of fibrous tissue

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had been changed to new bone. This was characteristic of the activity of the bone around the mandibular implant (Fig. 5). The response of the capsule to the implant. The capsule was slightly thickened; there was also a layer of dense fibrous tissue running parallel to the implant, with the remnant of the synovial lining being incorporated. The response of the glenoid fossa to the implant. The bone of the glenoid fossa surrounding the implant was vital, as was the bone marrow. In addition, the implant was covered with a thin layer of fibrous tissue (Fig. 6). Changes on unoperated joints in unilateral cases. The histologic features of the condyle, disc, and glenoid fossa were within the range of normal. There was slight irregularity in the muscle attachment of the lateral pterygoid muscle, probably caused by compensatory muscular overactivity of the pterygoids. Microradiographic

examination

Thin histologic sections prepared by a ground-section technique can absorb X-rays and can be used to study these structures. They can also provide information on the actual mineral deposition of the tissue concerned, especially with regard to bone growth and bone activity. This technique was described by Jowsey and colleagues14 in 1965, and Johns, lS in 1975, used it to demonstrate the proximity of the calcified bone to the implant. In this investigation the technique was used to demonstrate the exact location of the implant and its relation to the surrounding tissues (Fig. 7). Microradiographic observation of the ground sections demonstrated tolerance of the metallic joint and bone cement, with incorporation by healthy granulation tissue, collagen fibers, and new bone to such an extent as to justify complete biologic acceptance of the implant by the natural tissue. Extrapolation

of animal

investigation

to human

ankylosis

Three cases of unilateral fibrous ankylosis have been treated by this technique during the last 3% years. In one case only the glenoid fossa was replaced, while in the other two the temporomandibular joints were totally replaced. The technique used was excision of the condyle and coronoid process through a preauricular incision, and reflection of the attachment of the masseter muscle and medial pterygoid muscle through a submandibular incision. An elective tracheostomy was performed in every case. CLINICAL CASE 1

CASES

A 23-year-old woman was referred to the Oral Surgery Department of the University of Baghdad in 1974, with a history of not being able to open her jaws since the age of 1 year, following an attack of septicemia. The patient was in good general condition, with normal height and weight. Radiographic examination included lateral oblique and posteroanterior views and TMJ tomography. These confirmed the presence of a fibrous ankylosis of the right temporomandibular joint. Laboratory findings were normal. Chest films were negative. Operative

procedures

A blind intubation was performed and the right temporomandibular joint was approached through preauricular and submandibular skin incisions; the two incisions were chosen to ensure good access to the joint. Because the condyle was fused to the glenoid fossa, a low condylectomy

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Kummoona

TMJ. B, Preoperative photograph of the patient. and a coronoidectomy were performed. The masseter and medial pterygoid muscles were reflected and the mandible was mobilized by means of gags placed between the molars. A precast chromecobalt prosthesis to cover the glenoid fossa was fixed to the zygomatic root of the temporal bone with a stainless steel wire. The wound was closed in layers and a drain was inserted. The drain was removed after 48 hours, and a semiliquid diet for one week was prescribed. After that, active jaw exercise was encouraged and a normal diet was permitted. Six months postoperatively the jaw opening had reached 48 mm. Further surgery in the form of a genioplasty for residual micrognathia was planned. CASE 2

A 7-year-old boy was referred by his dentist in 1975 with a history of progressive difficulty in opening his jaw for the last 4 years. He had a history of juvenile rheumatoid arthritis at the age of 3 years. Examination revealed that the jaw opening was limited to 3 mm., micrognathia was present, and facial asymmetry was apparent. Radiographic examination showed a fibrous ankylosis of the right temporomandibular joint with an irregularly shaped flat condyle. It was thought that the patient was a suitable candidate for total replacement of the right temporomandibular joint by a chrome-cobalt prosthesis. Operative

procedure

An elective tracheostomy was performed for endotracheal intubation. A preauricular incision and a submandibular incision were again used to afford access to the right temporomandibular joint; the condyle and the coronoid process were resected and the medial pterygoid and masseter muscles

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Fig. 8. C, Photograph of patient 6 months after operation. D, Postoperative radiograph, posteroanterior viem. were reflected. This resulted in excellent jaw opening. The condylar prosthesis was fixed by using Surgical Simplex bone cement after the channel was made through the cancellous bone between the medial and lateral cortical plates of the ascending ramus along the long axis. The wound was closed and drains were inserted for 48 hours. Postoperative

course

,4ctive jaw exercise were commenced after 3 days, and at the end of 2 weeks jaw opening had reached 30 mm. A mechanical jaw exerciser was then constructed, and by the end of 6 months jaw opening had reached 42 mm. Full jaw movement has been maintained 2 years postoperatively. CASE

3

A girl of 8 from north of Iraq was referred to us with a history of inability to open her jaw. She had fallen from a height when she was 3 years old. A few months later the father noticed that the child could not open her jaw. She received no treatment until I examined her in January. 1977, when she presented with a complaint of stiff joint. Radiologic examination confirmed the presence of an ankylosis of the left temporomandibular joint. Operative

procedure

An elective tracheostomy was performed via preauricular and left submandibular incisions. A low condylectomy and coronoidectomy was performed, the medial pterygoid and masseter muscles

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Oral Surg. October, 1978

Kummoona

were reflected, and the left temporomandibular prosthesis similar to that used in Case 2. Postoperative

joint

was totally

replaced by a chrome-cobalt

course

Active jaw exercise was commenced

after 5 days, and a mechanical

jaw exerciser was con-

structed. At the end of one year, jaw opening had reached42 mm., and full jaw movement had been maintained during the last 8 months (Fig. 8). DISCUSSION

For many years metallic implants have been used for replacement of tissues damaged by disease or trauma. Chrome-cobalt was used because of its biologically inert character combined with the ability to form a chromium oxide film resistant to corrosion. In 1975 and 1976 I used this metal successfully for reconstruction of a traumatized orbital floor and for correction of diplopia and enophthalmos. 16*I7 These implants have been in situ for 5 years, with no sign of chemical or toxic irritation. Metal sensitivity, with the production of pain, may occur after a technically successful arthroplasty with a chrome-cobalt implant. The two surfaces of cobalt-chrome alloy rub together and cobalt and chrome are released locally and pass into the bloodstream to be excreted in the urine. A further consequence is obliteration of the blood vessels supplying the bone in which the prosthesis is inserted, leading to weakened fixation and loosening of the implant.” However, these problems do not occur in the replacement of the temporomandibular joints by this chrome-cobalt prosthesis, as there is no actual contact between the top prosthesis and the condylar prosthesis, because of the formation of a fibrous tissue layer between the two prostheses. This tissue originates from the periphery of the capsular wall and seems to function like a normal disc. It divides the joint into two compartments, as in the normal joint. The use of bone cement for anchoring the condylar prosthesis helps to form a permanent bond between the inert condylar implant and living bone by producing an accurate fit within the medullary channel of the ascending ramus of the mandible. The thermal effect of the bone cement after polymerizing was discussed in 1964 by Charnley, who believes that most of the heat is absorbed by the implant with minimal effect on the bony tissue. It is thought that the lubricant for the joints is provided either by transudation of an oily fluid, as demonstrated by Ring,‘” or by remnants of the synovial lining of the capsule. Furthermore, the fibrous layer provides a much lower coefficient of friction between the two parts of the prosthesis, with less muscle force required to provide movement in the joint. This unique feature of the two-part temporomandibular joint prosthesis is believed to be of considerable significance in providing long-term normal function in the restored joint. The experimental studies on Macaca it-us monkeys, combined with investigations in man, have demonstrated the biologic acceptability of the prosthesis under functional stress. It is submitted that these implants meet all the criteria for optimum biomechanical efficiency, in both the short and the long terms. Extrapolation of the animal experiments to the problem of human ankylosis has indicated that there is a considerable potential for joint reconstruction in this manner in specific cases of the disease in young adults in whom craniofacial growth is almost complete. In some children there may be an indication for a similar form of joint reconstruction where biologic procedures, such as replacement with a costochondral graft, are contraindicated.

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The two-part temporomandibu!ar joint prosthesis has made possible restoration of jaw morphology and normal functional movement in man. In my opinion, the prospects of a permanent cure for crippling ankylosis of the jaw appear to be better with the use of this technique than with many of the other methods that have been described in the literature. I would like to extend my thanks to the Also, I am greatly indebted to Professor D. of Surgeons of England, for his continued Professor B. Cohen, Director, Department England, for his kind advice and for the Research Committee of the Royal College research unit at Downe for this experimental Dental School, London, for his kind advice grateful to Mr. C. Hopps, Mr. B. Bidwell. Research Dental Unit at Downe. Orpington.

University of Baghdad for granting this research project. E. Poswillo, Professor of Teratology, the Royal College interest, advice, and encouragement. I am grateful to of Dental Sciences, the Royal College of Surgeons of facilities provided by his Department, and also to the of Surgeons of England for their permission to use the study. I am grateful to Dr. R. B. Johns, Subdean, Guys and permission to use his laboratory. I am also most George Smiler. and my colleagues and staff at the Kent, England.

REFERENCES

I. Hunter, J.: Works of John Hunter (edited by James F. Palmer), London, 1835.1837, Longman, Rees, Orme, Brown, Breen, and Longman. 2. Esmarch, H.: Cited in Erickson, E.: Science and Art of Surgery, Philadelphia, 1885, Lea Bros. & Co.. Vol. 12. 3. Barton, R.: Cited in Verneuil, A.: Arch. Gen. Med. 15:174, 1860. 3. Humphry, G. M.: Excision of the Condyle of the Lower Jaw, Assoc. Med. J. 4:6l, 1856. 5. Blair, V. P.: The Consideration of Contour as Well as Function in Operation for Chronic Ankylosis of Lower Jaw, Surg. Gynecol. Obstet. 46: 167, 1928. 6. Risdon, F.: Ankylosis of the Temporomaxillary Joint, J. Am. Dent. Assoc. 21: 1933-1937, 1933. 7. Kazanjian, V. H.: Ankylosis of the Temporomandibular Joint, Surg. Gynecol. Obstet. 67:333, 1938. 8. Dingman, R. 0.: Ankylosis of Temporomandibular Joint, Am. J. Orthod. Oral Surg. 32:120, 1946. 9. Wakeley, C. P. G.: The Mandibular Joint, Ann. Roy. Coil. Surg. 2: 1 I I, 1948. 10. Converse, J. M.: Surgical Treatment of Facial Injuries, ed. 3, Baltimore, 1974, Williams & Wilkins Company, p. 1224. I I. Poswillo, D. E.: Experimental Reconstruction of the Mandibular Joint, Int. J. Oral Surg. 3:400, 1974. I?. Christensen, W. R.: Arthroplastic Implantation of the TMJ, Oral Implantology, Springfield, 1970. Charles C Thomas Publisher, p. 284. 13. Kent. J. M., Lavelle, W. E., and Dolan, K. D.: Condylar Reconstruction: Treatment Planning. ORAL SURG. 32489,

1974.

14. Jowsey, J., Kelly, P. J., Riggs, B. L., Bianco, A. J., Jr., Scholz, D. A.. and Gershon Cohen, J.: Quantitative Microradiographic Studies of Normal and Osteoporotic Bone, J. Bone Joint Surg. 47A:785. 1965. 15. Johns, R. B.: Experimental Studies on Dental Implants, Proc. R. Sot. Med. 69:1, 1976. 16. Kummoona, R.. and Fattah. S. N.: Reconstruction of the Orbital Floor With Chrome Cobalt Mesh, J. Oral Surg. 33:542, 1975. 17. Kummoona, R.: Chrome Cobalt & Gold Implants for the Reconstruction of a Traumatized Orbital Floor, ORAL

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18. Editorial: Metal Sensitivity, Lancet 50:677, 1976. 19. Ring, P. A.: Ring Total Hip Replacement. In Jason, M. (editor): Sector Publishing, Ltd., p. 8. 20. Charnley, J. J.: The Bonding of Prostheses to Bone by Cement. Reprint

requeststo.

Dr. Raja Kummoona College of Dentistry Baghdad University Baghdad. Iraq

Total

Hip Replacement,

J. Bone Joint

Surg.

London.

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