|Year : 2021 | Volume
| Issue : 4 | Page : 233-240
Autogenous grafts for condylar reconstruction in the treatment of temporomandibular joint ankylosis: A systematic review on current concepts
AF M. Shakilur Rahman
Department of Oral and Maxillofacial Surgery, Rajshahi Medical College, Rajshahi, Bangladesh
|Date of Submission||04-Jun-2021|
|Date of Decision||18-Jun-2021|
|Date of Acceptance||23-Jun-2021|
|Date of Web Publication||20-Dec-2021|
A F M. Shakilur Rahman
Department of Oral and Maxillofacial Surgery, Rajshahi Medical College, Rajshahi
Source of Support: None, Conflict of Interest: None
Background: Temporomandibular joint (TMJ) ankylosis is distinguished by complexity or failure to open the mouth, leading to facial asymmetry, and malaligned teeth due to fusion of temporal bone with mandibular condyle. Objective: The present review aimed to discuss the different options of condylar reconstruction in TMJ ankylosis patients by autogenous grafts as reported in previous studies. Materials and Methods: A wide-ranging electronic search was performed by the following electronic databases: PubMed (Central), Hinari, and Google Scholar. A total of 25 full-text articles were found to meet the inclusion criteria and were reviewed for qualitative analysis in this study. Results: Surgery with or without condylar reconstruction is the only treatment alternative for TMJ ankylosis patients. Removal of ankylotic mass followed by condylar reconstruction with different existing autogenous grafts such as costochondral (CCG), sternoclavicular (SCG), coronoid, and metatarsal are done by surgeons. However, the costochondral graft is a preference by most surgeons due to its easy accessibility and adaptation. Distraction osteogenesis (DO) provides fewer complications with excellent efficient results in TMJ reconstruction. Conclusions: Up till now, any of the autogenous grafts for condylar reconstruction are not ideal for rebuilding the TMJ complex anatomy. CCG is still now the main choice for surgeons to reconstruct the TMJ in pediatric patients. DO has become popular recently.
Keywords: Ankylosis, autogenous graft, condylar reconstruction, tempomandibular joint
|How to cite this article:|
M. Shakilur Rahman A F. Autogenous grafts for condylar reconstruction in the treatment of temporomandibular joint ankylosis: A systematic review on current concepts. J Dent Res Rev 2021;8:233-40
|How to cite this URL:|
M. Shakilur Rahman A F. Autogenous grafts for condylar reconstruction in the treatment of temporomandibular joint ankylosis: A systematic review on current concepts. J Dent Res Rev [serial online] 2021 [cited 2022 Jan 22];8:233-40. Available from: https://www.jdrr.org/text.asp?2021/8/4/233/332926
| Introduction|| |
Temporomandibular joint (TMJ) ankylosis is a pathological condition where a bony or fibrous union of the anatomical joint structures occurs by an ankylotic mass with consequent failure of oral functional activities. Primarily, TMJ ankylosis is caused by trauma, infection, or failure of previous surgery. TMJ ankylosis may be classified according to the location (intra-articular or extra-articular), the involvement of tissue (bone, fibrous, or fibro-osseous), and the extension of ankylosis (complete or incomplete). There are different surgical management options for TMJ ankylosis such as gap arthroplasty, interpositional arthroplasty, and/or TMJ restoration by autogenous grafts or alloplastic material.,,
The treatment of TMJ ankylosis in pediatric and adult patients is always a challenging issue. The management of these patients varies from one country to another. Surgical management depends on: The extension and type of ankylosis; the patient's age; onset and time of operation; and the ankylosis site (either unilateral or bilateral). The outcome of any treatment option has not consistently proved as ideal. The postsurgical complications are mainly limited jaw movement as well as re-ankylosis (usually within 6 months postoperatively).
Ideal reconstruction of TMJ should be similar to normal joint anatomy, give efficient articulation, and permit adaptive development or remodeling. The difficulty in attaining these treatment objectives is demonstrated by the multiplicity of autogenous and alloplastic materials suggested or presently employed to rebuild the TMJ. Alloplastic graft reconstruction reproduces closer to normal TMJ anatomy, but there are likely complications for example wear and/or graft failure; giant cell foreign body reaction with a possible loosening of the implant consequential in occlusal disharmony; dislodgment or fracture; high price; dystrophic bone calcification; and deficient in growth. These drawbacks exclude the use of alloplastic joints in pediatric patients.,,,
Autogenous grafts for condylar reconstruction are mostly used even after they have limitations. The present review discusses the various options of condylar reconstruction by autogenous grafts as reported previously in different studies.
| Materials and Methods|| |
A wide-ranging electronic search was performed for the period from January 2010 to December 2020 by the following electronic databases: PubMed, Hinari, and Google Scholar. The most recent search took place on December 18th, 2020. We used keywords such as TMJ ankylosis, condylar reconstruction, autogenous graft. Manual exploration of oral and maxillo-facial surgery journals was also performed.
Randomized or quasi-randomized controlled trials (RCT), clinical trials (CT), retrospective studies (RSs), and clinical series comparing the various autogenous grafts such as costochondral (CCG), sternoclavicular (SCG), posterior border of mandibular ramus (PBR), coronoid process graft (CG), metatarsal (MG), reshaped ankylotic mass (RAM), and distraction osteogenesis (DO) for the reconstruction of the TMJ in the treatment of TMJ ankylosis were included. The English language-based articles were only included.
In vitro research, experimental studies, animal studies, review papers, and case reports were not included. Studies that compared autogenous graft to alloplastic or interposition material were also omitted. Articles older than 10 years were also removed from the analysis.
| Results|| |
The manual and computerized scans turned up 612 papers were found in databases like PubMed (n = 138), Hinari (n = 195), and Google scholar (n = 279), 486 of which were duplicates and had to be removed. The summaries of the existing 78 papers were reviewed, and the author read the entire text of the relevant studies for possible inclusion. A total of 24 full-text articles were found to meet the inclusion criteria and were reviewed for qualitative analysis in this study.,,,,,,,,,,,,,,,,,,,,,,, The study collection and analysis process is depicted in [Figure 1]. The present review article includes studies where different types of autogenous grafts were used to reconstruct TMJ in the treatment of ankylosis patients. The number of articles mentioned autogenous grafts like CCG (n = 08),,,,,,,, SCG (n = 09),,,,,,,,, CG (n = 06),,,,,, MG (n = 01), RAM (n = 01), PBR (n = 02),, and DO (n = 05),,,, in this review analysis. Data regarding study design, sample number, autogenous graft, mean maximum inter-incisal opening (MIO), re-ankylosis, follow-up period, and complications are included in this review. The results from this literature are tabulated as follows in [Table 1].
|Table 1: The various autogenous graft for temporomandibular joint reconstruction in temporomandibular joint ankylosis|
Click here to view
In ankylosis patients, CCG was employed as a graft material for TMJ restoration., For the restoration of TMJ in ankylosis patients, the CCG was compared to various graft materials such as SCG,, CG,, and DO. The SCG,,,,, CG,,, PBR,, DO,,,, MG, and RAM were some of the additional autogenous graft materials used for TMJ reconstruction the treatment of ankylosis patients. A study was also carried out to compare SCG with DO.
The CCG was widely implemented as a graft material for pediatric TMJ restoration in ankylosis patients.,, In a RS, Xia et al. found that both condyle-preserved arthroplasty and CCG were efficient operative treatments for pediatric patients with TMJ ankylosis. According to Sharma et al., the CCG enhanced mandibular uniformity and development in children with acceptable mouth opening. Sharma et al. reported that the CCG had improved mandibular symmetry and growth (P = 0.007) with adequate mouth opening (P < 0.001). Dar et al. conducted a prospective study to compare SCG and CCG as a graft material to reconstruct TMJ in pediatric unilateral TMJ ankylosis patients. The SCG group performed better in terms of MIO, re-ankylosis, mandible growth, and articular efficiency. With the limitation of limited sample size, Seth et al. reported that CCG was superior to SCG in terms of mandibular development and activity. For pediatric TMJ ankylosis, Kaur et al. conducted an RCT to evaluate and compare clinically meaningful results of condyle repair utilizing CCG and DO. All study parameters, such as MIO, improved with both CCG and DO. The differences between the groups were statistically insignificant. There was no evidence of re-ankylosis or an open bite. Condylar reconstruction with either CCG or DO for pediatric TMJ ankylosis had identical results.
Ankylosed TMJ reconstruction with SCG was studied retrospectively by Singh et al. Except in one case, there was a considerable improvement in MIO and jaw function. During follow-up, the radiological assessment revealed the graft's anatomical adaptability, with entire clavicle regeneration. Singh et al. performed a prospective study to assess the viability of SCG as an adaptable center in conjunction with buccal fat pad lining for TMJ reconstruction in patients with TMJ ankylosis. Clinical outcomes like MIO, jaw movement were improved with satisfactory occlusion in all cases. On radiological evaluation, there was a significant degree of adaption and remodeling of SCG.
Thirunavukkarasu et al. employed SCG to assess its viability for TMJ reconstruction in individuals with TMJ ankylosis. The average MIO achieved after surgery was >29 mm. In eighty percent of cases, the SCG was successfully integrated and renovated. Body length and midline deviation remained unchanged. Within a year, the donor site healed completely, and the clavicle was completely regenerated. Dayashankara Rao et al. observed that in the developing child, TMJ replacement using SCG resulted in a considerable rise in mandibular growth and ramal height, which had previously been limited due to ankylosis. Because it is reasonably straightforward to perform with few difficulties and acceptable results, the SCG could become a versatile and realistic choice for surgeons in TMJ reconstruction.,,, Kohli et al. evaluated TMJ efficiency in TMJ ankylosis patients after condylar repair with SCG versus DO. Following surgery, radiographic and clinical examinations were carried out at various time intervals. In the radiographic examinations, condylar resorption was significantly higher in the DO group (P = 0.005). DO was shown to have a higher rate of consequences. In terms of condylar shape, durability, and surgical wellbeing, Kohli et al. reported that SCG is preferable to DO.
Liu et al. compared the clinical results of autogenous coronoid process pedicled on temporal muscle grafts (ACPTMG) and autogenous free coronoid process grafts (AFCPG) for mandibular condyle restoration in patients with TMJ ankylosis. Both ACPTMG and AFCPG appear to be viable and feasible approaches to the management of TMJ ankylosis, based on positive clinical findings. When compared to AFCPG, ACPTMG had a lower rate of bone resorption and a superior long-standing treatment outcome. Yang et al. found that free grafting of autogenous CG for condyle restoration in patients with bilateral TMJ ankylosis is a safe and reliable approach.
The clinical effects of autogenous CG and CCG in condylar restoration for the management of isolated TMJ ankylosis in adults were explored in comparative analyses., Zhang et al. reported a retrospective comparison and concluded fewer complications of CG-treated patients over CCG in condylar reinstallation for the management of TMJ ankylosis. Fattouh stated that the study variables in both CG and CCG were acceptable and similar, with no notable variations between the two groups in mouth opening, lateral excursion, or mandibular deviation assessments pre- and post-operatively. Moreover, the CCG group had a considerably higher rate of donor-site complications. A possible alternative to the standard graft is autogenous CG for condylar repair in adults with TMJ ankylosis.,
TMJ restoration in pediatric patients using metatarsal bone graft after removal of ankylosis was studied by Al-Hudaid et al. Following TMJ reconstruction with MG, adequate MIO (>35 mm) was attained. Re-ankylosis was reported in two of the patients. TMJ reconstruction with MG after ankylosis removal results in an acceptable inter-incisal mouth opening.
PBR can be utilized for the reconstruction of the condyle in TMJ ankylosis patients. For the management of TMJ Ankylosis, several authors used the vertical ramus osteotomy (VRO) approach on the PBR to reconstruct the TMJ as a pedicled graft with myofascial temporalis or native articular disc interposition. VRO on the posterior border of the mandibular ramus resulted in an adequate (>35 mm) MIO and improved joint function without facing any postsurgical complications. VRO on the PBR appears to be an alternate and promising approach for RCU reconstruction in patients with TMJ ankylosis.,
Zhang et al. studied the effects of DO followed by arthroplasty or TMJ reconstruction on patients with TMJ ankylosis and secondary deformities. This study included patients with obstructive sleep apnea–hypopnoea syndrome (OSAHS). DO was performed in all cases first, followed by arthroplasty or TMJ restoration. The mean MIO and aesthetics of all patients improved. Snoring symptoms subsided, and there was a considerable enhancement in respiratory space. Only 10% of participants had a recurrence. In patients with bilateral TMJ ankylosis with micrognathia, Li et al. observed that arthroplasty followed by DO and advancement genioplasty as the subsequent surgical treatment improved MIO, rectified micrognathia, and cured OSAHS. Bansal et al. carried out a study of children with TMJ ankylosis. DO was accomplished after a gap arthroplasty. With a small change in lateral and protrusive jaw movement, the mean MIO was enhanced (>29 mm). Condyle reconstruction by DO is a viable treatment option for TMJ restoration in ankylosis patients. DO coupled with gap arthroplasty is a promising approach for treating TMJ ankylosis and improving MIO. The reconstructed TMJ had a significant incidence of neo-condylar resorption (P < 0.001).
| Discussion|| |
The mandibular condyle has great functional significance with little impact on facial aesthetics. The lower jaw deviates laterally more during the opening of the mouth due to the absence of a condyle than those having a condyle in a reconstructed mandible. It is difficult to masticate without a condyle. Denture retention is more difficult in patients who lack a condyle. The main purpose of mandibular condyle reconstruction is to diminish lateral deviation and get better stability. The condyle is the growth center for mandibular growth at a growing age. There is a constant physiological interaction between epiphyseal proliferation and the adjacent tissues at this stage of development. If there is an interruption in this physiological process, the consequences result in facial distortion, malocclusion, and other dental diseases.
Different types of surgical treatment of TMJ ankylosis have been mentioned in previous studies, such as gap arthroplasty, interpositional gap arthroplasty, and/or TMJ reconstruction by autogenous grafts or alloplastic materials. There are drawbacks of alloplastic materials in TMJ reconstruction, for example, infection and foreign body reaction. Different types of autogenous bone grafts are employed to reform the TMJ complex, counting costochondral grafts,,,,,,, clavicular bone,,,,,,, coronoid process,,,,,, metatarsal, ankylotic mass, and posterior border of ramus., These grafts have their own advantages and limitations. CCG is preferred by most surgeons for the reconstruction of TMJ in pediatric patients due to its growth potential. The cartilage portion of CCG must be shorter (2–3 mm) to prevent overgrowth of the graft. SCG has been used recently because of having similar properties to CCG. It produces an apparent scar postoperatively, which can be a disadvantage to patients.,, The unaffected coronoid process is grafted successfully for the reconstruction of TMJ in ankylosis patients. Re-ankylosis is the major postoperative complication of TMJ reconstruction. Postoperative physiotherapy improves the mouth opening and prevents re-ankylosis.,,, as stated in most of the studies. [Table 2] presents an abstract of the existing autogenous grafts and tissue for condylar reconstruction in TMJ ankylosis patients.
|Table 2: Autogenous grafts for mandibular condylar reconstruction: advantages and disadvantages|
Click here to view
DO is the newer alternative for TMJ reconstruction with a negligible incidence of reankylosis, gaining recognition recently. This procedure involves making a transport disc of bone from the mandibular ramus by creating a reverse L-shaped osteotomy. The medial attachment of the periosteum and muscles are preserved to ensure continuous vascular supply. The transport disc is made active after a latency period of 7 days. The disc is moved at 1.0 mm/day (0.5 mm twice daily) until it reaches the roof of the glenoid fossa. An over-distraction of 2–3 mm requires compensation of relapse. The newly generated bone is to consolidate for at least 3 months (consolidation phase). During the consolidation period, every patient is advised to engage in active physiotherapy to improve mouth opening and stimulate efficient adaptation of the transport disc to form a new condyle. Removal of the distractor is done after radiographic confirmation of osteogenesis.,,,
| Conclusions|| |
So far, no autogenous graft has proved ideal for the restoration of TMJ in ankylosis patients. The CCG is still now a choice of graft for TMJ reconstruction. DO has become popular recently for managing TMJ ankylosis patients.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Valentini V, Vetrano S, Agrillo A, Torroni A, Fabiani F, Iannetti G. Surgical treatment of TMJ ankylosis: Our experience (60 cases). J Craniofac Surg 2002;13:59-67.
Rowe NL. Ankylosis of the temporomandibular joint. J R Coll Surg Edinb 1982;27:67-79.
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.
Vasconcelos BC, Bessa-Nogueira RV, Cypriano RV. Treatment of temporomandibular joint ankylosis by gap arthroplasty. Med Oral Patol Oral Cir Bucal 2006;11:E66-9.
Vasconcelos BC, Porto GG, Bessa-Nogueira RV, Nascimento MM. Surgical treatment of temporomandibular joint ankylosis: Follow-up of 15 cases and literature review. Med Oral Patol Oral Cir Bucal 2009;14:E34-8.
Kaban LB, Perrott DH, Fisher K. A protocol for management of temporomandibular joint ankylosis. J Oral Maxillofac Surg 1990;48:1145-51.
Daniels S, Ellis E 3rd
, Carlson DS. Histologic analysis of costochondral and sternoclavicular grafts in the TMJ of the juvenile monkey. J Oral Maxillofac Surg 1987;45:675-83.
Mercuri LG. The use of alloplastic prostheses for temporomandibular joint reconstruction. J Oral Maxillofac Surg 2000;58:70-5.
Mercuri LG. Total joint reconstruction – Autologous or alloplastic. Oral Maxillofac Surg Clin North Am 2006;18:399-410, vii.
Saeed N, Hensher R, McLeod N, Kent J. Reconstruction of the temporomandibular joint autogenous compared with alloplastic. Br J Oral Maxillofac Surg 2002;40:296-9.
Speculand B, Hensher R, Powell D. Total prosthetic replacement of the TMJ: Experience with two systems 1988-1997. Br J Oral Maxillofac Surg 2000;38:360-9.
Kaur K, Roychoudhury A, Bhutia O, Bhalla AS, Yadav R, Pandey RM. Evaluation of success of transport disc distraction osteogenesis and costochondral graft for ramus condyle unit reconstruction in pediatric temporomandibular joint ankylosis. J Oral Maxillofac Surg 2020;78:1018.e1-1018.e16.
Xia L, He Y, An J, Chen S, Zhang Y. Condyle-preserved arthroplasty versus costochondral grafting in paediatric temporomandibular joint ankylosis: A retrospective investigation. Int J Oral Maxillofac Surg 2019;48:526-33.
Sharma H, Chowdhury S, Navaneetham A, Upadhyay S, Alam S. Costochondral graft as interpositional material for TMJ ankylosis in children: A clinical study. J Maxillofac Oral Surg 2015;14:565-72.
Singh V, Verma A, Kumar I, Bhagol A. Reconstruction of ankylosed temporomandibular joint: Sternoclavicular grafting as an approach to management. Int J Oral Maxillofac Surg 2011;40:260-5.
Singh V, Dhingra R, Bhagol A. Prospective analysis of temporomandibular joint reconstruction in ankylosis with sternoclavicular graft and buccal fat pad lining. J Oral Maxillofac Surg 2012;70:997-1006.
Thirunavukkarasu R, Balasubramaniam S, Balasubramanian S, Gopalakrishnan SK, Panchanathan S. Sternoclavicular Joint graft in temporomandibular joint reconstruction for ankylosis. Ann Maxillofac Surg 2018;8:292-8.
] [Full text]
Dayashankara Rao JK, Dar N, Sharma A, Sheorain AK, Malhotra V, Arya V. Evaluation of the sternoclavicular graft for the reconstruction of temporomandibular joint after gap arthroplasty. Ann Maxillofac Surg 2017;7:194-201.
Mohanty S, Kohli S, Dabas J, Singh C. Novel technique for harvesting the sternoclavicular graft. J Craniomaxillofac Surg 2017;45:290-4.
Dar N, Lone P, salman W, Rao D. Sternoclavicular grafting a pradigm shift in the management of TMJ ankylosis. J Med Sci Clin Res 2017;5:29642-7.
Kohli S, Mohanty S, Singh S, Sandeep, Dabas J, Patel R. The autogenous graft versus transport distraction osteogenesis for reconstruction of the ramus-condyle unit: A prospective comparative study. Int J Oral Maxillofac Surg 2017;46:1106-17.
Seth S, Gupta H, Kumar D, Agarwal R, Gupta S, Mehra H, et al.
Sternoclavicular graft versus costochondral graft in reconstruction of ankylosed temporomandibular joint. J Maxillofac Oral Surg 2019;18:559-66.
Al-Hudaid A, Aldialami A, Helmi J, Al-Wesabi M, Madfa A. Management of temporomandibular joint ankylosis in Yemeni children by metatarsal bone grafts. J Oral Res 2017;6:216-21.
Liu Y, Li J, Hu J, Zhu S, Luo E, Hsu Y. Autogenous coronoid process pedicled on temporal muscle grafts for reconstruction of the mandible condylar in patients with temporomandibular joint ankylosis. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109:203-10.
Yang X, Hu J, Yin G, Hu J, Luo E. Computer-assisted condylar reconstruction in bilateral ankylosis of the temporomandibular joint using autogenous coronoid process. Br J Oral Maxillofac Surg 2011;49:612-7.
Hu W, Thadani S, Mukul SK, Sood R. Autogeneous coronoid process as free graft for reconstruction of mandibular condyle in patients with temporomandibular ankylosis. Oral Maxillofac Surg 2014;18:313-23.
Zhang W, Gu B, Hu J, Guo B, Feng G, Zhu S. Retrospective comparison of autogenous cosotochondral graft and coronoid process graft in the management of unilateral ankylosis of the temporomandibular joint in adults. Br J Oral Maxillofac Surg 2014;52:928-33.
Bansal V, Mowar A, Dubey P, Bhatnagar A, Bansal A. 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. Br J Oral Maxillofac Surg 2016;54:280-5.
Fattouh H. The coronoid process graft: A new revolution in management of temporomandibular joint ankylosis. Egypt Dent J 2018;64:1047-54.
Parmar BS, Garg B, Mehta RD, Midha A, Thakkar DK. Ramus condyle unit reconstruction using vertical ramus osteotomy in temporomandibular joint ankylosis. J Maxillofac Oral Surg 2015;14:630-6.
Liu Y, Khadka A, Li J, Hu J, Zhu S, Hsu Y, et al.
Sliding reconstruction of the condyle using posterior border of mandibular ramus in patients with temporomandibular joint ankylosis. Int J Oral Maxillofac Surg 2011;40:1238-45.
Zhang W, Yang X, Zhang Y, Zhao T, Jia J, Chang S, et al.
The sequential treatment of temporomandibular joint ankylosis with secondary deformities by distraction osteogenesis and arthroplasty or TMJ reconstruction. Int J Oral Maxillofac Surg 2018;47:1052-9.
Li J, Zhu S, Wang T, Luo E, Xiao L, Hu J. Staged treatment of temporomandibular joint ankylosis with micrognathia using mandibular osteodistraction and advancement genioplasty. J Oral Maxillofac Surg 2012;70:2884-92.
Bansal V, Singh S, Garg N, Dubey P. 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. Int J Oral Maxillofac Surg 2014;43:227-36.
Xia L, Zhang Y, An J, Chen S, He Y. Evaluating the remodeling of condyles reconstructed by transport distraction osteogenesis in the treatment of temporomandibular joint ankylosis. J Cran Max face Surg 2020;48:494-500.
Mulliken JB, Ferraro NF, Vento AR. A retrospective analysis of growth of the constructed condyle-ramus in children with hemifacial microsomia. Cleft Palate J 1989;26:312-7.
Phillips JH, Rechner B, Tompson BD. Mandibular growth following reconstruction using a free fibula graft in the pediatric facial skeleton. Plast Reconstr Surg 2005;116:419-24.
Khadka A, Hu J. Autogenous grafts for condylar reconstruction in treatment of TMJ ankylosis: Current concepts and considerations for the future. Int J Oral Max Fac Surg 2012;41:94-102.
Lee JJ, Worthington P. Reconstruction of the temporomandibular joint using calvarial bone after a failed Teflon-Proplast implant. J Oral Maxillofac Surg 1999;57:457-61.
[Table 1], [Table 2]