Transport distraction osteogenesis as a method of reconstruction of the temporomandibular joint following gap arthroplasty for post-traumatic ankylosis in children: a clinical and radiological prospective assessment of outcome

How does changing the vector of transport disc distraction affect the outcomes of surgery in patients of temporomandibular joint ankylosis with obstructive sleep apnea?

PURPOSE

Temporomandibular joint ankylosis (TMJA) in children is associated with retrognathia, reduction in pharyngeal airway volume (PAV), and obstructive sleep apnea (OSA). Distraction-osteogenesis (DO) is the proven method in the management of OSA. There is paucity in literature about the effect of distraction vector on PAV. It can be expected that an oblique vector would improve PAV and relieve OSA. Thus, the study was designed to explore the feasibility, advantages, and disadvantages of this modified technique for managing TMJA and OSA simultaneously.

MATERIALS AND METHOD

The investigators designed a prospective study on patients of TMJA with retrognathia. Ethical approval was obtained (IECPG-547/14.11.2018). In all patients, simultaneous ankylosis release and mandibular distraction were performed. Primary outcome variables were improvement in 3-dimensional (3D) PAV and maximal interincisal opening (MIO). Secondary outcome variables were changed mandibular length, distraction relapse, and re-ankylosis. Paired t-test and multivariate ANOVA were used to assess all the parameters.

RESULT

The study included 13 joints in 8 patients of TMJA with retrognathia (2 unilateral and 6 bilateral ankylosis) with mean age of 14.25 ± 7.37 years. Mean distraction performed was 19 ± 4.0 mm. There was a statistically significant improvement of PAV by 225% (p = 0.002), a reduction in Epworth's scale (p = 0.017), an increase in MIO (p = 0.001), and an increase in mandibular length. Three patients had re-ankylosis at the 25-month follow-up.

CONCLUSION

The results of the present study conclude that modification of distraction vector improves 3D PAV and MIO in TMJA patients, with the added advantage of a reduction in overall treatment time and improved patient compliance.

Transport distraction osteogenesis compared with autogenous grafts for ramus-condyle unit reconstruction in temporomandibular joint ankylosis: A systematic review and meta-analysis

This systematic review was planned to assess the clinical outcomes of transport distraction osteogenesis (TDO) compared with autogenous grafts for reconstruction of the ramus condyle unit (RCU). We searched Medline, Embase, Cochrane Library, Clinicaltrial.gov, and the references of included trials. The primary outcome was maximal incisal opening (MIO). Of the 148 studies retrieved, five were included (TDO = 49, autogenous grafts =123). The mean difference in MIO between TDO and autogenous graft RCU reconstruction, based on the random-effects model was 1.28 mm (95% CI 0.167 to 2.403) in favour of TDO. Re-ankyosis was observed in four cases in the costochondral graft group and none in the TDO group. Reconstruction of the RCU using TDO is comparable to autogenous grafts after the release of TMJ ankylosis, though the evidence is weak considering the small number of trials, high risk of bias, and absence of long-term results.

Arthroplasty Followed by Distraction Osteogenesis Versus Distraction Osteogenesis Followed by Arthroplasty in the Management of TMJ Ankylosis: A Comparative Study

Aim

To compare treatment outcome of arthroplasty followed by distraction osteogenesis (AFD) and distraction osteogenesis followed by arthroplasty (DFA) in the management of mandibular deficiencies in temporomandibular joint (TMJ) ankylosis.

Materials and methods

A total of 20 patients with TMJ Ankylosis were included in the study. Patients were randomly divided into two groups. Group 1 consisted of patients for whom arthroplasty was done prior to distraction osteogenesis (AFD) for the correction of deficient mandible. Group 2 included patients where distraction osteogenesis was performed prior to arthroplasty (DFA). The treatment outcome was assessed based on maximum interincisal distance, overjet, corpus length, ramus height, upper airway, lower airway, duration of the procedure and the complications for the treatment at the end of 3, 6 and 12 months.

Results

After the treatment was ended, the patients of both groups had increase in mouth opening and appearance was improved remarkably. There was general increase in all the parameters in both the groups. But at the end of 12 months, airway and the ramus height were more stable and the control of the proximal segment was superior in DFA group. Open bite was noticed in 2 cases of AFD group which was treated by elastics. There required additional surgery for the removal of distractors in the AFD Group. Establishing the airway during the surgery was easier in AFD group.

Conclusion

The study concludes that distraction followed by arthroplasty was a better procedure for the management of TMJ ankylosis owing to its stable results and less number of surgeries.

A systematic review on the outcome of distraction osteogenesis in TMJ ankylosis

Introduction

TMJ ankylosis (TMJa) management by arthroplasty alone fails to address the deformity and the compromised airway. Distraction osteogenesis (DO) can offer a pragmatic solution to TMJa. The aim of the study was to generate evidence towards the role of DO in TMJa, evaluate its efficiency and develop an algorithm for use of DO in TMJa.

Material and methods

The research question was formulated using the PICOS statement for reporting guidelines in systematic reviews, where the efficiency of DO was evaluated in terms of mouth opening, correction of facial deformity and asymmetry, airway correction, and its long term effects.

Results

1130 articles reported DO as a treatment modality for TMJ ankylosis, of which 32 prospective studies, 16 retrospective and 2 RCTs were included in the study. DO was used for mandibular distraction in 45 studies and for simultaneous maxillamandibular distraction in only five studies. An algorithm for use of DO in TMJa was developed.

Conclusion

Although DO has proven its application in TMJ ankylosis cases, its best use is for correction of obstructive sleep apnoea. Relapse causing loss of posterior ramal height is a concern after transport DO. Prearthroplastic DO appears to best correct mandibular deformity. A maxillomandibular deformity requires simultaneous maxillomandibular distraction. However, a metanalysis is still awaited for effectiveness of DO in TMJ ankylosis.

Classification and surgical management of temporomandibular joint ankylosis: a review

The paper reviews various classifications and surgical techniques for the treatment of temporomandibular joint ankylosis. PubMed, EBSCO, Web of Science, and Google Scholar were searched using a combination of keywords. Articles related to classification, resection-reconstruction of the temporomandibular joint, and management of airway obstruction were considered and categorized based on the objectives. Seventy-nine articles were selected, which included randomized clinical trials, non-randomized controlled cohort studies, and case series. Though several classifications exist, most classifications are centered on the radiographic extent of the ankylotic mass and do not include the clinical and functional parameters. Hence there is a need for a comprehensive staging system that takes into consideration the age of the patient, severity of the disease, clinical, functional, and radiographic findings. Staging the disease will help the clinician to adopt a holistic approach in treating these patients. Interpositional arthroplasty (IA) results in better maximal incisal opening compared with gap arthroplasty, with no significant difference in recurrent rates. Distraction osteogenesis (DO) is emerging as a popular technique for the restoration of symmetry and function as well as for relieving airway obstruction. IA, with a costochondral graft, is recommended in growing patients and may be combined with or preceded by DO in cases of severe airway obstruction. Alloplastic total joint replacement combined with fat grafts and simultaneous osteotomy procedures are gaining popularity. A custom-made total joint prosthesis using CAD/CAM can efficiently overcome the shortcomings of stock prostheses.

Evaluation of Success of Transport Disc Distraction Osteogenesis and Costochondral Graft for Ramus Condyle Unit Reconstruction in Pediatric Temporomandibular Joint Ankylosis

PURPOSE

The costochondral graft (CCG) is considered the reference standard for pediatric temporomandibular joint reconstruction. It has the disadvantages of unpredictable growth, donor site morbidity, and the need for intermaxillary fixation. It has been reported that transport disk distraction osteogenesis (TDDO) can result in the formation of a neocondyle and disc. We performed a randomized trial to measure and compare clinically relevant outcomes of ramus-condyle unit (RCU) reconstruction using CCG and TDDO for pediatric temporomandibular joint ankylosis (TMJA).

MATERIALS AND METHODS

In the present randomized controlled trial (block randomization with a variable block size), pediatric patients with unilateral, nonrecurrent TMJA aged 3 to 16 years who had presented to our unit from December 2015 to June 2017 were enrolled. Instead of temporalis myofascial flap interposition, a buccal fat pad was used to fill the gap created by osteoarthrectomy. The primary outcome parameter was mouth opening. A mouth opening of at least 25 mm at the median follow-up point was considered success. The secondary outcome parameters were occlusion, laterotrusion, protrusion, reankylosis, neocondyle, chin deviation, facial asymmetry, midline shift, and neo-disc formation. Data were analyzed using the independent t test and rank sum test.

RESULTS

A total of 24 patients were enrolled in the CCG and TDDO groups (n = 12 in each group). Trauma (40.9%) was the most common etiology with a slight male preponderance (59.09%). The mean age was 10.32 ± 2.85 years. The average distraction achieved in the TDDO group was 10.42 mm. The median follow-up duration was 31.5 months (range, 24 to 39 months). The mean preoperative maximal incisal opening had improved from 8.5 ± 4.1 and 9.5 ± 7.1 mm in the CCG and TDDO groups preoperatively to 35.7 ± 2.7 and 34.4 ± 8.9 mm, respectively, at the median follow-up point (P < .005). RCU reconstruction with both modalities resulted in improvement in all the parameters; however, the intergroup comparison showed statistically non-significant differences. No reankylosis or open bite was found. The 3-hour delayed gadolinium-enhanced magnetic resonance imaging scan showed successful neo-disc formation.

CONCLUSIONS

Similar success can be achieved in RCU reconstruction using either CCG or TDDO for pediatric TMJA. Both techniques have some advantages and disadvantages. RCU reconstruction using CCG or TDDO results in formation of a neocondyle, maintenance of occlusion, and correction of facial asymmetry.

Management of Temporomandibular Joint Ankylosis With Dentofacial Deformities in Children

This retrospective study described the authors' experience in the treatment of temporomandibular joint (TMJ) ankylosis with dentofacial deformities in 18 pediatric patients during a 4-year period. These patients underwent different types of arthroplasty with condylar reconstruction, simultaneously with treatment of dentofacial deformities. Re-ankylosis was confirmed if maximal incisal opening (MIO) was <20 mm. Clinical outcomes were evaluated in terms of oral function, radiography, and medical photography. Patients were followed up for a mean time of 24.8 months. No infections, re-ankylosis, or permanent facial nerve damage were found during the hospitalization or follow-up period. All patients achieved significant improvements in MIO and oral function. The dentofacial deformities in most patients were improved to varying degrees. The results provided more useful information for the management of the pediatric patients with TMJ ankylosis and secondary dentofacial deformities. Early treatment and close follow-up play an important role in the management of these patients.

Temporomandibular joint reconstruction

PURPOSE OF REVIEW

Temporomandibular joint (TMJ) reconstruction represents one of the more challenging clinical problems that a head and neck surgeon encounters. Fortunately, the problem is fairly uncommon; however, at the same time, clear clinical guidelines have not been formulated. The goal of this review is to present the established solutions to this difficult reconstructive challenge and highlight key developments that have been recently published.

RECENT FINDINGS

Modern-day approaches to TMJ reconstruction include a handful of surgical modalities: costochondral grafting, revascularized tissue transfer, distraction osteogenesis, and alloplastic temporomandibular joint replacement (APTMJR). Over the past several years, publications have focused primarily on distraction osteogenesis and APTMJR. In particular, APTMJR is emerging as a highly successful and versatile surgical modality when faced with TMJ defects.

SUMMARY

With long-term follow-up after APTMJR approaching 20 years at several of the pioneering centers, alloplastic total joint replacement is emerging as the clinical standard when faced with TMJ defects in a variety of clinical situations. Unfortunately, the dogma of serious complications that occurred during early development may still be stalling widespread acceptance of APTMJR. Due to the complexity of the surgery, its relative infrequency and the lack of exposure in the majority of residency training programs, this surgery is currently best performed by tertiary referral centers.

The autogenous graft versus transport distraction osteogenesis for reconstruction of the ramus-condyle unit: a prospective comparative study

This study aimed to compare the joint function and morphology achieved following condylar reconstruction using sternoclavicular grafts (SCG) versus transport distraction osteogenesis (TDO) in temporomandibular joint (TMJ) ankylosis patients. Twenty-two patients with TMJ ankylosis underwent TMJ reconstruction with SCG or TDO (n=11 each). Radiographic and clinical evaluations were performed at 1 week and at 1, 3, and 6 months post-surgery. Clinical criteria examined included the duration of surgery, mean postoperative mouth opening, excursive jaw movements, and pain scores. The radiographic evaluation 6 months postoperatively (computed tomography) included subjective assessment of joint morphology and measurements of the mean condylar height, width achieved, and amount of condylar resorption. The χ² test and Student t-test were used to compare qualitative and quantitative variables, respectively. Similar mean mouth opening (SCG=31.8mm, TDO=32.1mm at 6 months), excursive movements, and pain scores were observed in the two groups throughout follow-up. Mean condylar resorption was significantly greater in the TDO group (TDO=7.0mm, SCG=2.7mm; P=0.005). The duration of reconstruction surgery was greater in the SCG group (P=0.035). A greater incidence of complications was observed with TDO. In conclusion, based on the protocols used in this study, SCGs are superior to TDO in terms of condylar morphology, stability, and surgical safety.

[Temporo-mandibular ankylosis]

Ankylosis of the temporomandibular joint is defined as a permanent constriction of the jaws with less than 30mm mouth opening measured between the incisors, occurring because of bony, fibrous or fibro-osseous fusion. Resulting complications such as speech, chewing, swallowing impediment and deficient oral hygiene may occur. The overall incidence is decreasing but remains significant in some developing countries. The most frequent etiology in developed countries is the post-traumatic ankylosis occurring after condylar fracture. Other causes may be found: infection (decreasing since the advent of antibiotics), inflammation (rheumatoid arthritis and ankylosing spondylitis mainly) and congenital diseases (very rare). Management relies on surgery: resection of the ankylosis block in combination with bilateral coronoidectomy… The block resection may be offset by the interposition temporal fascia flap, a costochondral graft or a TMJ prosthesis according to the loss of height and to the impact on dental occlusion. Postoperative rehabilitation is essential and has to be started early, to be intense and prolonged. Poor rehabilitation is the main cause of ankylosis recurrence.

Determination of size-specific exposure settings in dental cone-beam CT

OBJECTIVES

To estimate the possible reduction of tube output as a function of head size in dental cone-beam computed tomography (CBCT).

METHODS

A 16 cm PMMA phantom, containing a central and six peripheral columns filled with PMMA, was used to represent an average adult male head. The phantom was scanned using CBCT, with 0-6 peripheral columns having been removed in order to simulate varying head sizes. For five kV settings (70-90 kV), the mAs required to reach a predetermined image noise level was determined, and corresponding radiation doses were derived. Results were expressed as a function of head size, age, and gender, based on growth reference charts.

RESULTS

The use of 90 kV consistently resulted in the largest relative dose reduction. A potential mAs reduction ranging from 7 % to 50 % was seen for the different simulated head sizes, showing an exponential relation between head size and mAs. An optimized exposure protocol based on head circumference or age/gender is proposed.

CONCLUSIONS

A considerable dose reduction, through reduction of the mAs rather than the kV, is possible for small-sized patients in CBCT, including children and females. Size-specific exposure protocols should be clinically implemented.

KEY POINTS

• Fixed exposure settings in CBCT results in overexposure for smaller patients • For children, considerable dose reduction is possible without compromising image quality • A reduction in mAs is more dose-efficient than a kV reduction • An optimized exposure protocol was proposed based on phantom measurements • This protocol should be validated in a clinical setting.

Congenital Temporomandibular Joint Ankylosis: Case Report and Literature Review

Congenital temporomandibular joint (TMJ) ankylosis is an uncommon condition that presents itself at or soon after birth in the absence of acquired factors that could have contributed to the ankylosis such as infection and trauma. The experience of managing one such case is reported in light of a review of the literature on this condition. Key management principles include adequate removal of the ankylotic mass, costochondral grafting, and post-op physiotherapy. Most patients reported in the literature with the condition experienced relapse. This echoes our own experience where there was recurrence of the ankylosis. However, after removal of the ankylotic mass, the patient maintains a satisfactory maximal incisal opening (MIO) till the present day. The additional challenges faced in the congenital form in addition to the already complex management of acquired paediatric temporomandibular joint ankylosis are (1) much earlier insult to the TMJ, (2) reduced opportunity for neuromuscular development of the muscles of mastication, and (3) reduced compliance with postoperative physiotherapy programmes due to the younger age of these patients.

Simultaneous gap arthroplasty and intraoral distraction and secondary contouring surgery for unilateral temporomandibular joint ankylosis

Background

Temporomandibular joint (TMJ) ankylosis can be accompanied by various degrees of functional and esthetic problems. Adequate mouth opening, occlusal stability, and harmonious facial form are the main goals of treatment for ankylosis. Distraction osteogenesis has proven to be an excellent treatment for lengthening the ramus-condyle unit. However, various timings for distraction have been suggested, and there is no consensus on selection criteria for performing the procedure in stages or simultaneously with other treatments.

Case presentation

In this case report, concomitant intraoral distraction and gap arthroplasty was planned to treat TMJ ankylosis and associated facial asymmetry. After gap arthroplasty and 23 mm of distraction, the ramus-condyle segment was successfully lengthened and mouth opening range was significantly increased. The resultant interocclusal space was stably maintained with an occlusal splint for 4 months after distraction. Finally, good occlusion was achieved after prosthetic treatment. The remaining mandibular asymmetry was corrected with osseous contouring and augmentation surgery. The mouth-opening range was maintained at 35 mm 24 months after treatment.

Conclusion

Gap arthroplasty with intraoral distraction as a one-stage treatment and subsequent contouring surgery can be applied to correct ankylosis with moderate malocclusion and facial asymmetry.

Coronoid process and residual ankylotic mass as an autograft in the management of ankylosis of the temporomandibular joint in young adolescent patients: a retrospective clinical investigation

The aim of this non-randomised investigation was to assess the feasibility of using autogenous grafts (such as coronoid process and the resected ankylotic mass) in reconstruction of the condyle after gap arthroplasty for ankylosis of the temporomandibular joint (TMJ). Sixteen patients (23 joints) operated on between 2007 and 2009 were studied and postoperative measurements of maximum interincisal opening, bite force, range of movement, and infection were recorded. After a mean (SD) follow up of 55 (2.25) months mouth opening improved from 3 (3.84) mm to 33 (1.66) mm in patients treated with coronoid graft, while in patients treated with an ankylotic mass after a mean (SD) follow up of 58 (1.58) months it increased from 4 (2.64) mm to 26 (8.04) mm. Bite force six months postoperatively ranged from 18.25kg/cm(2) - 27.5kg/cm(2) after reconstruction with the coronoid process and 18.5kg/cm(2) - 23.25kg/cm(2) after reconstruction with the ankylotic mass. One patient developed reankylosis postoperatively and another developed infection, in both of which the ankylotic mass had been used. Both were managed successfully. Both the ankylotic mass and the coronoid process gave satisfactory results and seem to be options for reconstruction. However, the coronoid process graft was better than residual ankylotic mass in terms of masticatory efficiency, bite force, and range of movement.

[3D mandibular distraction planification in a case of severe temporomandibular ankylosis]

INTRODUCTION

When occurring in childhood, temporomandibular ankylosis joint is responsible for complex maxillofacial deformities, including mandibular growth deficiency. We present a case of temporomandibular joint ankylosis associated with severe mandibular asymmetry treated by mandibular bone distraction performed under computer assistance.

OBSERVATION

A 27-year-old patient presented with a severe facial asymmetry consisting in hypoplasia of the left hemi-mandible and maxilla. Mouth opening was non-existent. The CT-scan showed a left temporomandibular ankylosis. A left mandibular distraction was decided. The distraction characteristics (choice and positioning of the distractor, axis and amount of distraction) were determined preoperatively on the 3D CT-scan. The planning has been transferred to a navigation console (Kolibri®, Brainlab®). A combined intraoral and cutaneous was performed. Navigation allowed for an appropriate placement of the osteotomy line and fixation of the distractor. Distraction was started at the 5th postoperative day at the rate of 1mm per day and lasted 25 days without complication.

DISCUSSION

3D planning allows for better indication setting, better preparation of the procedure, reducing complications and operative time. It may help as an educational tool for young surgeons and for a better understanding from the patient. Navigation is an accurate method for the transfer of the planning in the operation room.