Bilateral temporomandibular joint ankylosis after bimaxillary surgery

J Oral Maxillofac 56:1437-1441.

Surg 1998

Bilateral Ankylosis

Temporomandibular After Bimaxillary Graeme

Andrew

W Wright,

Joint Surgery

MB BS, BDS, * and

A.C. Heggie, MB BS, MDSc, FFDRSCI,

FRACDS(OMS)

f

Fibrous ankylosis after prolonged maxillomandibular fixation (MMF) used in combination with rigid internal fixation has been described by Nitzan and Dolwick,’ and Aragon et al2 have discussed long-term hypomobility after orthognathic surgery. However, no cases have been reported on the progression to a true bony ankylosis of the temporomandibular joint (TMJ). The purpose of this report is to describe a case of bilateral bony ankylosis after bimaxillary surgery to correct a class II anterior open bite.

Report

of Case

A 26year-old woman was referred for the correction of an anterior open bite and mandibular deficiency. After the removal of all first premolars and 18 months of orthodontic arch alignment, a presurgical assessment showed vertical maxillary excess, mandibular deficiency, and microgenia (Fig 1A). She had a marked anterior open bite of 5 mm and an overjet of 12 mm (Fig 2A). Maximal interincisal opening was 50 mm, with no symptoms or signs of TMJ dysfunction. Radiologically, there was a Class II skeletal relationship with prominent antegonial notching and steep articular eminentia, but no obvious TMJ pathology. A Le Fort I segmental maxillary osteotomy with differential impaction, a bilateral sagittal split osteotomy for mandibular advancement, an advancement genioplasty, and an open rhinoplasty were performed. Postoperatively, the aesthetic and occlusal changes (Figs lB, 2B) were considered satisfactory, but mouth opening remained restricted, and the patient complained of pain in both TMJs at 6 weeks, which was initially controlled with the use of Orphenadrene, 100 mg twice daily (3M Pharmaceuticals, Australia). At 6 months postoperatively, the interincisal opening was still restricted to approximately 25 mm despite physiotherapy and continued muscle relaxant medication. She was debanded at 8 months postop eratively, and she then moved to a rural area, where routine review was difficult. *Oral and Maxillofacial Registrar, tAssociate,

Royal Melbourne

facial Surgery,

Melbourne

Royal Melbourne

Hospital

Craniofacial

Hospital.

and Head, Oral and MaxiUoUnit, Royal Children’s

Hospi-

tal of Melbourne. Address

correspondence

Head,

Oral and Maxillofacial

Royal

Children’s

Hospital

and

reprint

Surgery, of Melbourne,

requests

Melbourne

to Dr Craniofacial

Flemington

Heggie: Unit,

Rd, Parkville

FIGURE 1. A, Preoperative lateral view of patient.

3052, Australia. @ 1998

American

Association

of Oral and Maxillofacial

Surgeons

0278.2391/98/5612-0013$3.00/0

1437

lateral

view

of patient.

5, Postoperative

1438

FIGURE bite.

2. A, Preoperative 5, Postoperative occlusion

TMJ ANKYLOSIS

occlusion showing

showing occlusal

severe anterior correction.

open

AFTER BIMAXILLARY

SURGERY

Her mandibular mobility slowly continued to decrease and, at 30 months, she was pain free but the interincisal opening was restricted to 13 mm, with no lateral excursive movements. Imaging of the TMJs included plain films, tomograms, magnetic resonance imaging, and computed tomography views. Almost complete obliteration of the joint spaces was seen, and no translation of the condyles occurred during opening. The discs were undetectable, and bilateral degenerative and proliferative changes were noted. Laterally, both joints were almost completely encased in bone proliferating from the superiolateral aspect of the fossa and the medial surface of the condyles (Fig 3). Bilateral arthrotomies were performed with a standard preauricular approach,3 and bony recontouring of the fossae and condyles was performed. Temporalis fascial flaps were sutured to the discal remnants and soft tissues medially and anteriorly. Bilateral intraoral coronoidectomies also were performed because it was surmised that the coronoid processes were causing mechanical interference with mandibular movement because of the degree of proximal segment rotation. Healing progressed uneventfully, and intensive physiotherapy was initiated 3 weeks after surgery. Her opening increased from 15 mm in the early postoperative period to

FIGURE

3. Preoperative radiographs. A, Initial panoramic radiograph. 6, Immediate preoperative panoramic radiograph.

WRIGHT AND HEGGIE 32 mm over the following 3 months, associated with complete resolution of pain. On routine review at 2 years after joint surgery, maximal interincisal opening was 29 mm (Fig 4), laterotrusive movements were present, and the patient was pain free. Relapse of half of a unit of Class II was noted in centric occlusion, but no further treatment was planned.

Discussion Changes in TMJ function after orthognathic surgery have been reviewed by Freihofer and Petresevic.* In their retrospective study of 118 mandibular advancements, no restriction in mouth opening was noted, and only one patient with clicking and pain of the affected joint showed any radiologic evidence of arthrosis. In a prospective study by Aragon et aI2 it was concluded that maximal interincisal opening was reduced after orthognathic surgery. Reduction in postoperative opening was found in those patients undergoing only mandibular sagittal osteotomies (29%)

FIGURE 3. (Cont’ d) C, Tomograms of left and rig1 lt TMJs showanoting derangement oi normal omv. D. 3D CT scan s of right TMJ bone formashdwing heterotopic tion and ankylosis.

1439 and also in bimaxillary surgery cases (28%). This hypomobility was thought by Crawford et al5 to be due to degenerative changesin the TMJ resulting from MMF, atrophy of skeletal fibers due to immobilization, muscle shortening due to detachment of muscle from bone, and changes associatedwith the muscle-tendon interface. They believed that the main cause of postoperative restriction in opening was surgical trauma to the mucosa, muscle, and surrounding structures of the joint. Rotskoff6 reported other predisposing factors in the development of joint pathology after orthognathic surgery, which included preexisting joint disease, traumatic manipulation of the proximal segment, and improper application of rigid internal fixation. In this case, extensive areas of condylar erosion were evident, with changes in the articular surface of the condyles aswell asdestruction of the discs. These changeswere observed by Nitzan and Dolwickl when describing the pathogenesis of a case of fibrous ankylosis. They suggested that females in the older

1440

TMJ

FIGURE 4.

Maximal

interincisal

opening

at 2 years

age-groups with preexisting joint disease were at greater risk of developing fibrous ankylosis. Nitzan and Dolwickl studied eight patients who developed severe pain and restriction of mouth opening after orthognathic surgery. Seven had undergone mandibular sagittal ramus osteotomies, and four had undergone simultaneous Le Fort I osteotomies. All had MMF applied for a period of 6 to 8 weeks, and postoperative examination showed posteriorly displaced condyles with no translation during mouth opening. Surgical interventions included releaseof adhesions,arthroplasties, disc repositioning, and repair of perforations. It was thought that these caseswere best described as fibrous ankyloses and that they resulted from posterior displacement of the condyle combined with an extended period of MMF. It was postulated that the TMJ pathologic condition was associated with rigid internal fixation because of the inability of the osteotomy sites to adjust to any minor discrepancies in the occlusion. Thus, when rigid internal Iixation was used in combination with prolonged MMF, pressure was transmitted to the TMJ, and the potential for dysfunc-

ANKYLOSIS

AFTER

BIMAXILLARY

SURGERY

tion was exacerbated if the patient had preexisting joint pathology. Feinerman and Piecuch’ were unable to find long-term problems in patients treated with rigid fixation in relation to TMJ dysfunction. However, Moore and Stoelinga8observed that ClassII caseswere at a higher risk of developing postoperative limitation of movement. Animal studies9,1°on larger joints, and TMJs” have shown extensive degenerative changes in the articular cartilage and synovial membrane after prolonged periods that restrict normal movement. It is difficult to extrapolate these findings to the TMJs of the patient reported, although intracapsular trauma due to a significantly altered loading pattern resulting from counterclockwise autorotation of the condyles is possible. Semi-rigid miniplate and screw fixation may increase fragment stability at osteotomy sites, but is likely to increase loading of the temporomandibular articular surfaces, particularly in casesof mandibular lengthening. Pain and limitation of opening also have been associated with progressive condylar resorption,5 which frequently has been associated with late skeletal relapse after mandibular sagittal ramus osteotomies8 O’Ryan and Epker,i2 speculating on the causes of progressive condylar resorption, found a variable trabecular pattern in condylar morphology with different occlusal patterns and suggested that these patterns vary according to the response to loading and stress. The pathogenesis of the bony ankylosis after orthognathic surgery in this report is unclear. It can be argued that the steep articular eminentia, together with condylar autorotation and the use of rigid internal fixation, predisposed to significant joint disturbance. The alteration of the skeletal pattern also may have resulted in a more unfavorable anatomic environment for the joints by mechanically restricting normal movements and therefore compromising the success of routine postoperative physiotherapy. The combination of increased loading and prolonged hypomobility may have been responsible for the marked pathologic joint changes, but the extensive bony proliferation seen in this case is not easily explained. Although residual fragments of the discs were seen at the periphery of the joints, particularly medially, fragmentation and dissolution must have occurred because of the increased loading of the joints postoperatively that exceeded the reparative ability of the discal tissue. Consequently, a large area of bone to bone contact resulted bilaterally that, together with restricted movement, appears to have initiated heterotopic bone formation and progressive ankylosis. This suggested pathogenesis for the bony ankyloses is summarized in Figure 5.

LAMBERT

1441

G.M. DE BONT

Skeletal

class II pattern with

anterior

References

openbite

+ Steep articular

emineotia

I

I I

Surgery autorotation

Counterclockwise

(rigid fuation): of condyles and increased

loading /

I Neuromuscular

adaptation

resulting

in dysfunctional

TMJ response

I Condylar

resorption,

loss of discs, increased + Hypomobility

surface area of bone contact

I

I Progression

FIGURE

of fibrosis

5. Suggested

to bony ankylosis

pathogenesis

of ankylosis.

Becausepreexisting joint pathology has been implicated in the development of postoperative condylar changes, routine screening of TMJs for pathologic conditions has been recommended. However, because of the difficulty in predicting such changes, it is our view that comprehensive TMJ imaging should be restricted to symptomatic patients.

J Oral Maxiilofcc 56.1441-1442,

1. Nitzan DW, Dolwick MF: Temporomandibular joint fibrous ankylosis following orthognathic surgery: Report of eight cases. Int J Adult Orthod Orthognath Surg 4:7, 1989 2. Aragon SB, Van Sickels JE, Dolwick MF, et al: The effects of orthognathic surgery on mandibular range of motion. J Oral Maxillofac Surg 43:938, 1985 3. Howerton DW, Zysset M: Anatomy of temporomandibular joint and related structures with surgical anatomical considerations. Oral Maxillofac Surg Clin North Am 1229, 1989 4. Freihofer HPM, Petresevic D: Late results after advancing the mandible by sagittal splitting of the rami. J Maxillofac Surg 3:250, 1975 5. Crawford JG, Stoelinga JW, Bljdorp PA, et al: Stability after re-operation for progressive condylar resorption after orthognathic surgery: Report of seven cases,J Oral and Maxillofac Surg 52:460, 1994 6. Rotskoff K: Temporomandibular joint consequences in orthognathic surgery. Oral Maxillofac Surg Clin North Am 1:261, 1989 7. Feinerman DM, Piecuch JF: Long term effects of orthognatbic surgery on the temporomandibular joint: Comparison of rigid and nonrigid fixation methods. Int J Oral Maxillofac Surg 24:268, 1995 8. Moore KE, Stoelinga PJW: The contributing role of condylar resorption to skeletal relapse following mandibular advancement surgery: A report of five cases. J Oral Maxillofac Surg 49:448, 1991 9. Trias A: Effect of persistent pressure on articular cartilage: An experimental study. J Bone Joint Surg Br 43:376,1961 10. Lange&old A, Michelsson JE, Viderman T: Osteoarthdtis of the knee joint in the rabbit produced by immobilisation. Acta Orthop Stand 50: 1, 1929 11. Gliieburg RW, La&n DM, Blaustein DI: The effects of irnmobilization on the primate temporomandibular joint: A histologic and histochemical study. J Oral Maxillofac Surg 40:3, 1982 12. O’Ryan F, Epker BN: Temporomandibular joint function and morphology: Observations on the spectra of normalcy. Oral Surg 58:272, 1984

Surg 1998

Discussion Bilateral Ankylosis Lambert

Temporomandibular After Bimaxillary

Joint Surgery

G.M. de Bent, DDS, PhD

Professor and Chairman, Department Surgery, University Hospital Groningen, Netherlands.

of Oral and Groningen,

Maxillofacial The

Temporomandibular joint (TMJ) ankylosis after bimaxillary surgery is a rare condition. TMJ condylar resorption following orthognathic surgery, however, has been frequently described. Patients with absolute mandibular retrog nathism and a high mandibular plane angle appear to be prone to condylar resorption after bimaxillary surgery and are at risk of relapse and TMJ signs and symptoms due to the accompanying degenerative changes.rx* However, the cause of the TMJ degenerative changes is still unclear. Recently, a

causal relationship between oxidative stress and TMJ degenerative joint disease has been hypothesized.3 According to this hypothesis, mechanical stress leads to the accumulation of damaging free radicals in affected articular tissues of susceptible individuals. If oxidative stress is the potential mechanism for the initiation of molecular events that can culminate in degenerative TMJ diseases, the degree of individual susceptibility to degenerative changes will play a major role. In two individuals, the same joint loading and the same amount of mechanical stress can have a completely different effect on TMJ behavior; one stressor may cause TMJ damage in an individual, and the same stressor may stimulate and strengthen the TMJ structures in another. The biology of the human TMJ and related structures in response to stressors is still unclear. Unexpected TMJ sequelae after orthognathic surgery are related to the same basic mechanisms: individual susceptibil-