2021, Number 1
Total temporomandibular joint replacement in patients with ankylosis: presentation of two clinical cases
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ABSTRACT
Introduction: Temporomandibular joint (TMJ) ankylosis is defined as the pathologic condition where the mandible is fused to the glenoid cavity by bony and/or fibrotic tissues, limiting mouth opening, making mastication and speech difficult. Objective: To improve mandibular function by decreasing pain and preventing reankylosis in the cases presented, as well as to provide information about the management of TMJ ankylosis. Presentation of cases: Two TMJ ankylosis cases are presented, both with opening limitation (13 and 10 mm), intense throbbing type pain in the preauricular area. In both cases, extension studies (radiographies, tomographies, stereolithography) were performed for the planning of surgical times. A complete TMJ replacement was carried out by means of an acetabulum and a stock condylar prosthesis (Biomet Microfixation), the surgical technique consisted of perauricular approach with anterosuperior extension and posterior submandibular approach, mandibular movements were immediately verified and physiotherapy exercises were indicated for six months. Results: In the first case a 35 mm opening was achieved with protrusive and lateral mandibular movements and stable occlusion at five years of follow-up. In the second case, an opening of 30 mm was achieved with preserved mandibular movements. In both cases, the patients referred satisfaction and security to food chewing and asymptomatically. Conclusions: To achieve effective, satisfactory, and lasting treatment, an individualized approach is necessary in each case, choosing as the first option the one with the least morbidity for the patient.INTRODUCTION
Temporomandibular joint (TMJ) ankylosis is the pathological condition in which the mandible is fused to the glenoid cavity by bony and fibrotic tissues, limiting the mouth opening and producing difficulty chewing and speech. It can be fatal if advanced airway management is necessary in case of emergencies.1,2 Its etiology is diverse; the most common is trauma (13-100%), followed by infections (10-40%) and systemic diseases (10%), such as ankylosing spondylitis, rheumatoid arthritis or psoriasis, tuberculosis, gonorrhea, and scarlet fever by the hematogenous route. In the case of trauma, it is hypothesized that an intra-articular hematoma, adhesions, and bone are formed excessively, resulting in ankylosis. The epidemiology of TMJ ankylosis varies from country to country. It usually develops before the age of 10 years but can be found at any age and is generally diagnosed between 10 and 30 years. It presents a male/female ratio of 1.4:1.2. Unilateral is more common than bilateral, in a ratio of 1.5:1, with a greater preference for the right side. In Mexico, the most frequent cause is direct trauma to the mandible, followed by infectious processes and systemic diseases.3-5
TMJ ankylosis is classified into four types: type I when the condyle is flattened or deformed, and there are fibrous adhesions around the joint; type II, when the condyle is distorted but still distinguishable; however, there is already a bony fusion of the condyle with the outer edge of the glenoid cavity, but without fusion of the articular disc; type III when there is a bony fusion from the mandibular ramus to the zygomatic arch, with the inner part of the glenoid cavity and the articular disc intact, and type IV when the bony fusion is wide and deep and extends from the ramus and glenoid cavity, completely replacing the joint architecture.6 Topazian in 1964, classifies ankylosis into three stages: stage I: bony ankylosis limited to the condylar head; stage II: extending to the sigmoid notch, and stage III: extending to the coronoid process.7 TMJ ankylosis is also classified as pseudoankylosis and true ankylosis. True ankylosis, in turn, is subclassified into fibrous, cartilaginous, bony, and fibro-osseous.8,9 TMJ ankylosis can also be classified according to the site involved, being true ankylosis when intracapsular and false or pseudo-ankylosis when the limitation of motion occurs due to an injury or physical obstruction outside the TMJ.10
Since the 60's of the last century, arthroplasty has been considered the surgery of choice for the treatment of TMJ ankylosis since excellent long-term results have been reported.11-14 However, a literature review from 1946 to 1994 on the different types of prefabricated prostheses for total temporomandibular joint replacement (TMJR) showed that most of the reports are made on a small sample of patients and with a follow-up of fewer than five years.15 In Mexico, only one study focused on the follow-up of surgical treatment of TMJ ankylosis by Kimura, who reported 52 patients who presented fibrous ankylosis type I and II in 36.4% and bony ankylosis, classification III and IV in 63.6%, with a follow-up of 18 years.5 In the last ten years, to our knowledge, only two articles have been presented in the midline databases, one showing a case of a prefabricated prosthesis and the other reporting a case of custom-made prosthesis.16,17
There are different types of techniques and materials involved in treating TMJ ankylosis by arthroplasty, for example, auricular cartilage, temporal muscle flap, fat, and alloplastic materials, such as Teflon and Silastic. As for autologous grafts, costochondral, sternoclavicular, rib, second and fourth metatarsal, ulnar head, part of the fibula, and iliac crest grafts are proposed.18-25 Finally, there are titanium custom-made prostheses. In growing patients, the best option is autologous grafts. In contrast, after seven years of age and in adult patients who have undergone reoperation and present bone resorption, loss of vertical dimension, or systemic disease such as childhood rheumatoid arthritis, the prognosis is better using custom-made commercial prostheses.26
The most common complications of total TMJ replacement are re-ankylosis, uncontrolled bone growth, bone resorption, donor site morbidity, fracture, pain, damage to the facial nerve's zygomatic branch, and presence of anterior open bite.27-29 To contribute to a better understanding of the treatment of TMJ ankylosis, two cases of complete TMJ replacement are presented.
PRESENTATION OF CASES
CASE 1
This case was a 60-year-old female patient who started suffering in October 2014. She presents a history of a left TMJ arthroplasty in 2005 and a right TMJ arthroplasty in 2012. The patient reported severe throbbing pain in the right preauricular area during chewing, mandibular deviation at the minimum opening, inability to feed properly, and a limitation of the opening of 13 mm (Figure 1). In addition, the orthopantomography (Figure 2A), the CT and MRI showed ankylosis of the right TMJ type II, where the deformed mandibular condyle was identified with a fusion on the external border of the glenoid cavity, with the middle and internal part still respected, and the left TMJ showed a deformed condyle but without the presence of significant adhesions (Figure 2 B and C).
The osteotomy, arthroplasty, and remodelling were designed using a stereolithographic model, as well as the adaptation of the acetabulum and stock or prefabricated condylar prosthesis (Biomet Microfixation)30 (Figure 3 A and B).
The surgical technique consisted of a preauricular approach with anterosuperior field hockey stick extension. Previous trichotomy of the area superior to the helix and anterior to the tragus of the ear, marking of the approach, lidocaine with epinephrine subcutaneously was infiltrated (Figure 4A). We made an incision up to the superficial layer of the temporal fascia; in this way, the superficial temporal vessels and the auriculotemporal nerve are retracted together with the anterior flap, the obtuse dissection was continued over the zygomatic arch just in front of the tragus to protect the temporal branches of the facial nerve. Subsequently, when the dissection was one centimetre below the zygomatic arch, access was gained to the articular capsule.31 All the ankylosed tissue was removed by osteotomy of the condyle and coronoidectomy, verifying mandibular movements (Figure 4B). After remodelling the glenoid cavity, the acetabulum's size was confirmed to fix the definitive acetabulum32,33 (Figure 4 C-E).
The submandibular approach was then performed, after surgical marking two centimeters below the edge of the mandible, following some skin wrinkles and infiltration of anesthetic with a vasoconstrictor. An incision was made, dissection by planes up to the plastima muscle, where it is continued undermining it by using Metzenbaum scissors up to the superficial layer of the deep cervical fascia, where the facial vein and artery were located and ligated. The masseter muscle dissection and desperiostization form of the mandible's entire external face and ramus was continued until it communicates with the preauricular approach, adapting the condylar prosthesis to the external mandibular face using a previous undermining of this bony structure31-33 (Figure 4F). The prosthesis was taken to occlusion, and the position and height were corroborated for subsequent fixation with screws. Mandibular movements were then verified with direct vision. We concluded with placing a periprosthetic abdominal fat graft as an interface to reduce the risk of recurrence. Rehabilitation was started in the first 24 hours with jaw movement exercises.32,33
CASE 2
This case was a 41-year-old female patient, who in 1999, began to suffer from left temporomandibular ankylosis secondary to a gunshot wound with an entry orifice at the level of the left TMJ. Subsequently, she presented intense stabbing pain in the left preauricular area, the impossibility of adequate feeding, and a limited opening of 10 mm. The CT scan showed a type IV ankylosis (according to Sawhney) of the left TMJ, where an extensive bony fusion was observed, extending from the glenoid branch and cavity, completely replacing the architecture of the joint (Figure 5A). Therefore, the same study protocol was performed by our service (Figure 5B y C). With the same surgical management under balanced general anesthesia, the preauricular and submandibular approaches described in case 1 were performed, then TMJ arthroplasty, coronoidectomy, placement, as well as adjustment of the acetabulum and stock condylar prosthesis (Biomet Microfixation) coinciding with the previous planning in the stereolithography (Figure 6 A-C).
Patients were instructed to repeat each physiotherapy exercise 10 times five times a day for at least two months, following the TMJ ankylosis prevention protocol, which consists of Maximum opening, right and left lateral excursion, protrusive excursion. In addition, exercises such as chewing gum and hot fomentation for 10 minutes, five times a day, are indicated to facilitate rehabilitation. All these exercises are continued for six months regularly. Mouth opening devices are available if the mouth opening is minimal and can be used until they can place their index, middle, and ring fingers up to the first distal interphalangeal folds. At that point, it is replaced by an appropriately sized mouth accessory to keep the jaw dilated for 1 hour, and this forced opening is repeated five times a day. Forced opening exercises are discontinued once patients can achieve normal opening.34
In case 1 after surgery, the patient presented 20 millimeters of mouth opening, initiating forced physiotherapy the day after RTATM and for six months more. She even refers to continuing with them occasionally on her initiative. Currently, with a five-year follow up there is no evidence of re-ankylosis, presenting an opening of 35 mm (Figure 7 A and B), with protrusive and lateral mandibular movements and stable occlusion. Comparison of a coronal slice against a lower skull view showed symmetry of the temporomandibular joints (Figure 8 A and B).
Regarding case 2, the prosthesis is functional, with no data of re-ankylosis (Figure 9 A and B). The beginning of the protocol presented a mouth opening of only 10 mm, post-surgery of 15 mm, and after 20 years of 30 mm, with preserved mandibular movements. It is worth mentioning that the patient with paresthesia in the preauricular area, which he had before surgery as a sequel of the firearm projectile wound. Both patients report satisfaction and safety when chewing food and are asymptomatic so far.
DISCUSSION
Complications can be transoperative or postoperative, either immediate or delayed. Surgical management of the TMJ is delicate. The roof of the glenoid cavity is involved with the middle cranial fossa, so any damage to these structures could cause an intracranial or cerebrospinal hematoma. In addition, Frey's syndrome could be caused by injury to the parotid gland. Damage to nerve structures is the most frequent complication followed by infections. In the patients reported, it was preferred to ligate the facial artery, and they presented paresthesia and transitory paresis associated with post-surgical edema, which completely reverted in one and a half to two months. Late complications are foreign body reactions or recurrence, which to date have not occurred. The best approach to minimize the complication rate of TMJ surgery is careful surgical planning.33,35
Al-Moraissi et al. reported that the best results are obtained using the temporalis muscle interposition arthroplasty technique compared to simple arthroplasty, suggesting that it is the treatment of choice. It also suggests that stock prosthesis has a higher success rate in pain reduction than costochondral grafting.36
Only those patients who have undergone multiple unsuccessful surgeries should be considered candidates for using a prosthesis because several studies establish that the scar tissue found in multi-treated patients does not provide an environment conducive to the success of an autogenous tissue such as the costochondral graft. For its integration, it is necessary the formation of capillaries and blood vessels that must penetrate tissue with a maximum thickness of 180 to 220/μm, being that the scar tissue surrounding a previously operated joint has an average thickness of 440/μm so that it would fail. The choice in pediatric patients will continue to be the costochondral graft for its growth potential, although its disadvantages are fractures, higher recurrence rate and surgical time, an additional surgical site, donor site morbidity, and potential overgrowth of the graft. In multi-treated adult patients, the long-term choice should be using a stock prosthesis with anatomy closer to the real one, reduction of reattachment, and immediate physiotherapy with the consequent greater benefit. Mercuri found that patients with rheumatoid arthritis who underwent prosthetic reconstruction of the temporomandibular joint experienced better results than those who underwent reconstruction with autogenous bone.37,38
Fanaras, et al. mention that choosing to use a custom or commercially available TMJ prosthesis gives us a more predictable reconstruction, decreases surgical time, decreases donor site morbidity, and provides immediate function onset. The only disadvantage is the cost, but if we compare that when an autograft is performed, it is necessary longer surgical time and hospital stay and a higher rate of reinterventions, in the long term, the difference between one or the other is minimal if we use a prefabricated prosthesis like ours.39
In both surgical treatments, costochondral grafting and use of a costochondral prosthesis, it is essential to place autologous fat grafts around the prosthesis or graft to eliminate the dead space around it, thus avoiding the formation of a clot, minimizing the pluripotential cells, avoiding the formation of fibrosis, heterotopic calcification, and re-ankylosis. Wolford and Karras published the first study evaluating the use of fat grafts placed around TMJTR, where there was no radiographic or clinical evidence of heterotopic calcifications in either fat graft group. In contrast, the control group without fat grafting developed heterotopic bone and required reoperation, demonstrating that autologous fat grafting was an essential adjunct.39,40
Over 500,000 hip prostheses are fitted each year, and a large number of knee joint prostheses, so there is more experience with the effect of materials used in hip and knee joint prostheses than with TMJ prostheses. Therefore, although it should be considered as the last option for the treatment of temporomandibular ankylosis due to its high cost at an institutional level, its use should begin to be normalized as in orthopedics, especially in specific cases such as patients with chronic degenerative diseases associated with a high rate of re-ankylosis, in which multiple surgeries could be avoided in the future, causing a higher cost and risk for the patient.41
CONCLUSIONS
Treatment in TMJ ankylosis aims to improve mandibular function by decreasing pain and preventing re-ankylosis. There are different treatment modalities and reconstructive principles for this TMJ pathology. It is essential to mention that the management of a growing individual will always be different compared to an adult. The indications for each technique vary according to the severity of the problem, the patient's age, the ability to perform postoperative physical therapy, the surgeon's experience, and socioeconomic factors. Each case should be individualized before choosing the surgical treatment, choosing as the first option the one with the most minor morbidity regardless of cost, although the result will always depend on the patient's cooperation, active physical therapy, and regular follow-up. The authors have concluded that, to achieve an effective, satisfactory, and long-lasting treatment, an individualized approach is necessary in each case. Despite having a small sample of only two cases, we have a follow-up of 20 years with success. In Mexico, other authors regarding the use of stock prosthesis have not documented failures and have the same sample size as us but with a much smaller follow-up than ours.
REFERENCES
AFFILIATIONS
1 Jefe de Servicio de Cirugía Maxilofacial del Hospital Regional "Lic. Adolfo López Mateos", ISSSTE.
2 Cirujano Maxilofacial del Hospital Naval de Acapulco, Secretaría de Marina.
3 Médico adscrito al Servicio de Cirugía Maxilofacial del Hospital Regional "Lic. Adolfo López Mateos", ISSSTE.
CORRESPONDENCE
Doroteo Vargas Lo?pez. E-mail: doroteovargas@hotmail.comReceived: Enero 2020. Accepted: Julio 2020.