Printer Friendly




The aim of this study was to compare the treatment outcome of thirty unilateral temporomandibular joint (TMJ) ankylosis cases treated in Pakistan Institute of Medical Sciences (PIMS), Islamabad within four years by either silastic or acrylic interpositional arthoplasty. Patients having bilateral TMJ ankylosis, age less than 16 years, coronoidectomy required during procedure, already operated cases and medically compromised patients were excluded from the study. Pre and post-operative assessment was done by thorough history, physical examination and radiographic evaluation (OPG and CT scan) to determine the cause of ankylosis, the maximal inter-incisal opening, complications including infection, presence of facial nerve paralysis and recurrence rate. The maximal inter-incisal opening in the pre-operative period ranged from 0-11mm and was recorded at a mean of 32.7+5.8mm for cases treated with silastic interposition and 29.5+6.8mm for the ones treated with acrylic one year after surgery.

Infections, swelling, pain and nerve injuries were reported in both the groups post-operatively. Both silastic and acrylic were found to be statistically similar in terms of maximal inter-incisal opening, complications and recurrence rates. Recurrence was observed in only one patient treated by acrylic inter-positioning. Silastic however demonstrated itself to be a better choice in terms of handling and patient tolerability.

Key Words: TMJ ankylosis, interpositional graft, comparison of arthroplasty.


Ankylosis is a Greek term which means 'stiff joint'. Temporo-mandibular joint (TMJ) ankylosis is inability to open the mouth due to a fibrous or bony union between the mandibular condyle and the glenoid fossa, which replaces the articulation, resulting in restriction of movement.1

The incidence of TMJ ankylosis is less in developed countries due to better understanding of condylar fractures and their complications. In developing countries like Pakistan lack of access to medical facilities and dearth of qualified professionals, the incidence of TMJ ankylosis is still comparatively high.2

The etiology of true TMJ ankylosis remains mainly inappropriately treated joint fractures due to trauma especially in childhood leading to facial deformity with restriction in oral functions which has devastating psychological repercussions.3,4

TMJ ankylosis is best managed through surgical intervention followed by physiotherapy.5 Three basic surgical techniques are currently employed namely, gap arthroplasty, interpositional arthroplasty, and joint reconstruction. Several authors have researched and developed different techniques for the management of TMJ ankylosis but tarnished by the problem of recurrence.6

In recent years interpositional arthroplasty has gained popularity because of satisfactory long-term results and low recurrence rate but choice of interpositional materials is still controversial. Various autogenous tissues such as temporal muscle and fascia, fascia lata, cartilage, dermis, full thickness skin, perichondrium, rib, metatarsal, sternoclavicular and ulnar heads have been used as interpositional materials. The operative time and sophistication of procedure along with morbidity at the donor and recipient site have been reported after autogenous interpositional grafting.7

The alloplastic materials like vitallium, tantalum, teflon, acrylic and silastic or silicone rubber have also been used from time to time. In 1958 Walker8 described the use of silicone as an alloplastic interpositional material in TMJ ankylosis surgery. Many further studies demonstrating the use of medical grade silicone showed successful long-term results but infection, extrusion and displacement were also reported as complications of silicone implants.9,10

Acrylic is another alloplastic material used as interpositional material with encouraging results. It is a biocompatible and inexpensive material that can be fabricated locally. In 1968 Borcbakan11 used acrylic in the treatment of TMJ ankylosis. Acrylic was used in many studies after that in different shapes but infection, extrusion, foreign body reaction and problems of securing the graft in place were noted along with an additional procedure to prepare the acrylic graft.12,13,14

This study was designed to compare the results of silastic and acrylic as interpositional materials in the management of TMJ ankylosis. The core aim was to minimize postoperative morbidity and recurrence of TMJ ankylosis so that the sufferings of patients may be marginalized.


Study was carried out in Oral and Maxillofacial

Surgery Department, Pakistan Institute of Medical Sciences (PIMS), Islamabad, Pakistan. Thirty patients with a clinical and radiographic diagnosis of unilateral TMJ ankylosis were included. Patients having bilateral TMJ ankylosis, age less than 16 years, coronoidectomy required during procedure, already operated cases and medically compromised patients were excluded from the study.

Patients were randomly distributed into two groups of fifteen patients each. Demographic data as well as clinical observations were documented. The degree of mouth opening was assessed by measuring the inter-incisal distance. A standard OPG was advised to every patient but in a few cases CT scan was also advised to accurately assess the medio-lateral extent of ankylotic mass. All patients were operated under general anesthesia by blind nasal or fiberoptic assisted nasal intubation in an elective list. The surgical approach to the joint was by A1Kayat and Bramley modified pre-auricular approach.15 Bony mass causing the ankylosis was removed creating space of 5-6mm with trial opening of the mouth using the gag.

In group A silastic (3-4mm thickness) was shaped and fitted into the gap and secured with a surgical soft stainless steel 25-gauge wire and titanium micro plate to the lateral surface of the joint eminence (Fig 1). In group B prefabricated, heat cured acrylic (3-4mm thickness) was shaped, trimmed and fitted into the gap and secured with wire (Fig 2). After achieving homeostasis, suction drain was placed and the wound closed in layers with tight mastoid dressing.

Immediate inter-incisal distance was noted at the operating table following completion of the procedure. Passive physiotherapy using chewing gum was advised from the 2nd post-operative day and active physiotherapy using wooden spatulas from the 6th which continued for at least 6 months. Patients were recalled for follow-up visits on 1st, 3rd and 6th week then 3rd, 6th and 12th month. Inter-incisal opening less than 15mm was considered as re-ankylosis. Complications like swelling, pain, interpositional material displacement and any nerve damage was documented. The collected data were analyzed by SPSS.


Most of the patients were in the third decade of life. There were 56.7% (n-17) male and 43.3% (n-13) female patients (Table 1). The main etiological factor was trauma either due to road traffic accident (RTA) or fall especially at childhood during kite flying (Fig 3). 66.7% (n-20) patients reported with ankylosis of the right side and 33.3% (n-10) with left. Pre-operative inter-incisal distance (I ) ranged from 0-11mm (Table 2).

Post-operative inter-incisal (I ) opening was recorded at different follow-up visits (Table 2). In initial visit mouth opening of both groups was almost same but after one year follow-up post-operative mouth opening was found somewhat better in group "A" 32.74+5.86mm as compared to group "B" 29.54+6.89mm. When both groups were compared statistically with independent t test, p value was not significant (p 0.05).

However, when preoperative mouth opening was compared with postoperative mouth opening after one year a significant increase was found. p value was significant (p [?] 0.05). The net mean increase in inter-incisal distance was 28.87+2.87mm in patients treated with silastic and 26.17+4.13mm in the patients treated with acrylic.

Post-operative complications, swelling, midline deviation, occlusal derangement, were negligible and statistically similar in both groups. More discomfort and pain was experienced during mouth opening exercises by the patients treated with acrylic interpositioning. Transient facial nerve injury was found in six (20%) patients (two from group "A" and four from group "B") and permanent injury to temporal branch of facial nerve was found in one patient from group "B". Graft was removed in one patient from group "A" and two patients from group "B" due to infection and displacement. Recurrence was observed in only one patient from group "B" in this study.



Group A###Male###8###53.3



Group B###Male###9###60.0




The treatment of TMJ ankylosis poses a significant challenge because of technical difficulties and a high incidence of recurrence. Interpositional arthroplasty with alloplastic materials was found to be superior to the other techniques because it has a shorter operative time, ease of application, minimized facial asymmetry and low recurrence rate. Additionally no donor site morbidity occurs with alloplastic use.16


Time of Analysis###Group A###Group B

###Mean###Std. Devi-###Std. Error###Mean###Std.Devi-###Std. Error###p val-



Immediately on Oper-###38.2667###2.15362###.55606###38.3333###2.16025###.55777###0.05

ation Table

1week I2###35.9333###4.63630###1.19709###34.7333###4.30061###1.11041###0.05

3 weeks I2###34.0000###5.11301###1.32017###31.8667###4.38938###1.13333

6 weeks I2###34.1333###5.24904###1.35530###31.6000###4.91063###1.26792

3 Months I2###34.1333###5.44933###1.40701###31.1333###5.98649###1.54571

6 Months I2###33.2667###5.96977###1.54139###30.3333###5.92412###1.52960

1 year I2###32.7333###5.86109###1.51333###29.5333###6.88546###1.77782

Net Increase###28.8666###2.86427###0.73955###26.1666###4.13081###1.06657

Silicon and acrylic are easily available, economical, biocompatible and friendly to implant at resected ankylosed space.2,17 Silastic and acrylic were compared as interpositional materials in the treatment of TMJ ankylosis. Improvement in the inter-incisal distance/ mouth opening and reduction in post-operative complications are the main aims of any surgical techniques in the treatment of TMJ ankylosis.

The predominant age in this study was third decade of life. Higher incidence of TMJ ankylosis in this age group was also reported by Akhtar et al.,2 Huang et al.,18 He et al.19 Limited mouth opening and difficulty in eating were the most common complaints of the patients however dyspnea and difficulty of speaking were also noted in some patients.

Post-operative inter-incisal mouth opening (I ) was evaluated and compared in both groups at different post-operative follow-ups. A gradual reduction in mouth opening was recorded in both groups in the initial visits (Table 2). The reason of this reduction may be difficulty in exercise due to pain or discomfort which is also reported by Huang et al.20 During the later visits, mouth opening remained stable in both groups due probably to better compliance and motivation for mouth opening exercises. At the last follow-up visit reduced inter-incisal distance (I ) was found in both groups but less in group "A". This may be because silastic is soft rubber like material which allows more compressibility as compared to acrylic which virtually is non-compressible. Recurrence was observed in only one patient from group "B" who had mouth opening of 11mm post-operatively in this study. These findings were consistent with similar local and international studies.2,21,22,23

Swelling was observed in majority of the patients 93.3% (n-28) on the first week follow-up visit. Infection occurred in a total of four (13.3%) patients to which specific antibiotics were prescribed after culture and sensitivity. In one patient (group A) infection subsided with antibiotics and in three patients (one from group Aand two from group B) infection resolved after removal of the interpositional material. Infection occurred due to breakage of wire and non-compliance of antibiotic therapy by patients. Swelling and infection were also reported with silastic and acrylic interpositioning in some other studies.2,13,17

Surgery is not the endpoint of TMJ ankylosis treatment. Postoperative care, as in every surgery is very important and non-compliance often results in failure. TMJ ankylosis in this regard needs more care and attention as post-operative mouth opening exercises are important for the successful outcome of arthroplasty. Chidzonga24 reviewed 32 patients and reached to the final conclusion that failing to do jaw exercises was the main cause of relapse. The single most concern in the post-operative rehabilitation i.e. mouth opening exercises were found in almost every study regarding the treatment and management of TMJ ankylosis.25


It is concluded that the TMJ ankylosis should be dealt with aggressive surgical approach using interpositional material followed by early mobilization of the joint in the form of aggressive physiotherapy. It results not only in satisfactory mouth opening and jaw function, but also ensures in reduction of subsequent recurrence rate. Silastic is an excellent interpositional material in handling and ease of use. However, acrylic is a good alternative if silastic is not available.


Special thanks to Dr. Qaim-ud-din, Dr. Usman Qadir, and Prof. Iqbal Memon (Head, Anesthesia Department, PIMS, Islamabad) for their help and support. I am also thankful to Mr. Abdul Hafeez Mughal (IDLLab Technician) for helping to prepare acrylic grafts.


1 Malik NA. Text book of Oral and Maxillofacial Surgery. New Delhi, India: Jaypee Brothers Medical Publishers (Pvt) Ltd; 2002: 207-18.

2 Akhtar MU, Abbas I, Shah AA. Use of silastic as interpositional material in the management of unilateral temporomandibular joint ankylosis. J Ayub Med Coll Abbottabad. 2006; 18: 73-76.

3 He D, Yang C, Chen M, Yang X, Li L. Effects of soft tissue injury to the temporomandibular joint: report of 8 cases. Br J Oral Maxillofac Surg. 2013; 51: 58-62.

4 Toyama M, Kurita KK, Koga K, Ogi N. Ankylosis of the temporomandibular joint developing shortly after multiple facial fractures. Int J Oral Maxillofac Surg. 2003; 32: 360-62.

5 Khan Z. Management of temporomandibular joint ankylosis: literature review. Pakistan Oral and Dent. Jr. 2005; 25(2): 151-55.

6 Tanrikulu R, Erol B, Gorgun B. The contribution to success of various methods of treatment of temporomandibular joint ankylosis (a statistical study containing 24 cases). Turk J Pediatr.2005; 47: 261-65.

7 Su-Gwan K. Treatment of temporomandibular joint ankylosis with temporalis muscle and fascia. Int J Oral Maxillofac Surg. 2001; 30: 189-93.

8 Walker RV. Arthroplasty of the ankylosis of temporomandibular joint. Am Surg. 1958; 24: 6-15.

9 Karaca C, Barutcu A, Baytekin C, Yilmaz M, Menderes A, Tan O. Modifications of the inverted T-shaped silicone implant for treatment of temporomandibular joint ankylosis. J Cranio Maxillofac Surg. 2004; 32: 243-46.

10 Abbas I, Jamil M, Jehanzeb M, Ghous SM. Temporomandibular joint ankylosisexperience with interpositional gap arthroplasty at Ayub Medical College Abbottabad. J Ayub Med Coll Abbottabad. 2005; 17: 67-69.

11 Borcbakan MC. L'utilisation du condyle acrylique dans I'ankylose temporomaxillaire. Rev Stamatol Chir Maxillofac. 1968; 7: 600-03.

12 Guven O. Treatment of temporomandibular joint ankylosis by a modified fossa prosthesis. J Cranio-Maxillofac Surg. 2004; 32:236-42.

13 Erdem E, Alkan A. The use of acrylic marbles for interposition arthroplasty in the treatment of temporomandibular joint ankylosis: follow-up of 47 cases. Int J Oral Maxillofac Surg. 2001; 30: 32-36.

14 Pitta MC, Wolford LM. Use of acrylic spheres as spacers in staged temporomandibular joint surgery. J Oral Maxillofac Surg. 2001; 59: 704-06.

15 Al-Kayat A, Bramley P. A modified pre-auricular approach to the temporomandibular joint and malar arch. Br J Oral Maxillofac Surg. 1979; 17: 91-94.

16 Guven O. A clinical study on temporomandibular joint ankylosis. Auris Nasus Larynx. 2000; 27: 27-33.

17 Ortak T, Gurhan UM, Nezih S, Omer E, Ragip O, Hidir K. Silicon in temporomandibular joint ankylosis surgery. J Cranio-fac Surg. 2001; 12: 232-36.

18 Huang IY, Lai ST, Shen YH, Worthington P. Interpositional arthroplasty using autogenous costal cartilage graft for temporomandibular joint ankylosis in adults. Int J Oral Maxillofac Surg. 2007; 36: 909-15.

19 He D, Ellis E, Zhang Y. Etiology of temporomandibular joint ankylosis secondary to condylar fractures: The role of concomitant mandibular fractures. J Oral Maxillofac Surg. 2008; 66: 77-84.

20 Huang IY, Lai ST, Shen YH, Worthington P. Interpositional arthroplasty using autogenous costal cartilage graft for temporomandibular joint ankylosis in adults. Int J Oral Maxillofac Surg. 2007; 36: 909-15.

21 Ramezanian M, Yavary T. Comparion of gap arthroplasty and interpositional gap arthroplasty on the temporomandibular joint ankylosis. Acta Medica Iranica. 2006; 44: 391-94.

22 Vasconcelos BC, Porto GG, Nogueira BRV, Nascimento MM. Surgical treatment of temporomandibular joint ankylosis: Follow-up of 15 cases and literature review. Med Oral Patol Oral Cir Bucal. 2009; 14: 34-38.

23 Zhi Li, Zu-Bing Li, Jin-Rong Li. Surgical management of posttraumatic temporomandibular joint ankylosis by functional restoration with disk repositioning in children. Plast Reconstr Surg, 2007; 119: 1311-16.

24 Chidzonga MM. Temporomandibular joint ankylosis: review of thirty two cases. Br J Oral Maxillofac Surg. 1999; 37: 123-26.

25 Singh V, Bhagol A, Dhingra R, Kumar P, Sharma N, Singhal R. Management of temporomandibular joint ankylosis type III: lateral arthroplasty as a treatment of choice. Int J Oral Maxillofac Surg. 2013 Oct 4; (10.1016/j.ijom.2013.08.013).

Correspondence: Dr. Khalid Mahmood Siddiqi, Assistant Professor, Islamabad Medical and Dental College, Islamabad Dental Hospital, Main Murree Road, Bhara Kahu. Islamabad-Pakistan Email:, Phone: 051-2232045 Ext 26, 0300-5105215.

Assistant Professor, Head, Oral and Maxillofacial Surgery Department, Frontier Medical and Dental College, Abbottabad-Pakistan.

Professor and Head Oral and Maxillofacial Surgery Department, Quaid-e-Azam Postgraduate Medical College, Pakistan Institute of Medical Sciences, Islamabad, Pakistan.

Assistant Professor, Oral and Maxillofacial Surgery Department, Quid-E-Azam Postgraduate Medical College, Pakistan Institute of Medical Sciences, Islamabad, Pakistan.

Senior Registrar, Oral and Maxillofacial Surgery Department, Islamabad Medical and Dental College, Oral Surgery.
COPYRIGHT 2013 Asianet-Pakistan
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2013 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Siddiqi, Khalid Mahmood; Arshad, Omar; Ahmad, Zahoor; Marwat, Muhammad Umar Farooq; Baig, Muhammad Z
Publication:Pakistan Oral and Dental Journal
Article Type:Report
Geographic Code:9PAKI
Date:Dec 31, 2013

Terms of use | Privacy policy | Copyright © 2021 Farlex, Inc. | Feedback | For webmasters