Browse > Article
http://dx.doi.org/10.5125/jkaoms.2021.47.4.239

Classification and surgical management of temporomandibular joint ankylosis: a review  

Upadya, Varsha Haridas (Department of Oral and Maxillofacial Surgery, Yenepoya Dental College and Hospital, Yenepoya (Deemed to be University))
Bhat, Hari Kishore (Department of Oral and Maxillofacial Surgery, Yenepoya Dental College and Hospital, Yenepoya (Deemed to be University))
Rao, B.H. Sripathi (Yenepoya (Deemed to be University))
Reddy, Srinivas Gosla (Faculty of Dentistry, All India Institute of Medical Sciences (AIIMS) Rishikesh)
Publication Information
Journal of the Korean Association of Oral and Maxillofacial Surgeons / v.47, no.4, 2021 , pp. 239-248 More about this Journal
Abstract
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.
Keywords
Temporomandibular joint; Ankylosis; Classification; Arthroplasty; Distraction osteogenesis;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Goncalves JR, Gomes LC, Vianna AP, Rodrigues DB, Goncalves DA, Wolford LM. Airway space changes after maxillomandibular counterclockwise rotation and mandibular advancement with TMJ Concepts® total joint prostheses: three-dimensional assessment. Int J Oral Maxillofac Surg 2013;42:1014-22. https://doi.org/10.1016/j.ijom.2013.04.009   DOI
2 Coleta KE, Wolford LM, Goncalves JR, Pinto Ados S, Cassano DS, Goncalves DA. Maxillo-mandibular counter-clockwise rotation and mandibular advancement with TMJ Concepts total joint prostheses: part II--airway changes and stability. Int J Oral Maxillofac Surg 2009;38:228-35. https://doi.org/10.1016/j.ijom.2008.11.021   DOI
3 Mercuri LG, Ali FA, Woolson R. Outcomes of total alloplastic replacement with periarticular autogenous fat grafting for management of reankylosis of the temporomandibular joint. J Oral Maxillofac Surg 2008;66:1794-803. https://doi.org/10.1016/j.joms.2008.04.004   DOI
4 Roychoudhury A, Yadav R, Bhutia O, Aggrawal B, Soni B, Gowswami D, et al. Is total joint replacement along with fat grafts a new protocol for adult temporomandibular joint ankylosis treatment? Int J Oral Maxillofac Surg 2017;46:236. https://doi.org/10.1016/j.ijom.2017.02.797   DOI
5 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. https://doi.org/10.1016/j.ijom.2018.01.022   DOI
6 Sesenna E, Magri AS, Magnani C, Brevi BC, Anghinoni ML. Mandibular distraction in neonates: indications, technique, results. Ital J Pediatr 2012;38:7. https://doi.org/10.1186/1824-7288-38-7   DOI
7 Lam DJ, Tabangin ME, Shikary TA, Uribe-Rivera A, Meinzen-Derr JK, de Alarcon A, et al. Outcomes of mandibular distraction osteogenesis in the treatment of severe micrognathia. JAMA Otolaryngol Head Neck Surg 2014;140:338-45. https://doi.org/10.1001/jamaoto.2014.16   DOI
8 Miloro M. Mandibular distraction osteogenesis for pediatric airway management. J Oral Maxillofac Surg 2010;68:1512-23. https://doi.org/10.1016/j.joms.2009.09.099   DOI
9 Gunaseelan R, Anantanarayanan P, Veerabahu M, Vikraman B. Simultaneous genial distraction and interposition arthroplasty for management of sleep apnoea associated with temporomandibular joint ankylosis. Int J Oral Maxillofac Surg 2007;36:845-8. https://doi.org/10.1016/j.ijom.2007.05.004   DOI
10 Li KK, Powell NB, Riley RW, Guilleminault C. Distraction osteogenesis in adult obstructive sleep apnea surgery: a preliminary report. J Oral Maxillofac Surg 2002;60:6-10. https://doi.org/10.1053/joms.2002.29049   DOI
11 Srivastava D, Luthra P, Mishra S, Chandra L, Sharma S, Singh H. Technique of dual distraction for correction of unilateral temporomandibular joint ankylosis with facial asymmetry: a case series. J Oral Maxillofac Surg 2019;77:2555.e1-12. https://doi.org/10.1016/j.joms.2019.07.017   DOI
12 Mansoor N, Khan M, Mehboob B, Din Q. Gap vs interpositional arthroplasty in the management of temporomandibular joint ankylosis. Pak Oral Dent J 2013;33:8-12.
13 Genecov DG, Barcelo CR, Steinberg D, Trone T, Sperry E. Clinical experience with the application of distraction osteogenesis for airway obstruction. J Craniofac Surg 2009;20 Suppl 2:1817-21. https://doi.org/10.1097/SCS.0b013e3181b6c1b0   DOI
14 Jia W, He Y, Helal H, Wang Y, Li J. One-stage technique for treatment of ankylosis of the temporomandibular joint, secondary micrognathia, and a prominent mandibular angle. Br J Oral Maxillofac Surg 2019;57:701-3. https://doi.org/10.1016/j.bjoms.2019.05.022   DOI
15 Yadav R, Bhutia O, Shukla G, Roychoudhury A. Distraction osteogenesis for management of obstructive sleep apnoea in temporomandibular joint ankylosis patients before the release of joint. J Craniomaxillofac Surg 2014;42:588-94. https://doi.org/10.1016/j.jcms.2013.07.031   DOI
16 Feiyun P, Wei L, Jun C, Xin X, Zhuojin S, Fengguo Y. Simultaneous correction of bilateral temporomandibular joint ankylosis with mandibular micrognathia using internal distraction osteogenesis and 3-dimensional craniomaxillofacial models. J Oral Maxillofac Surg 2010;68:571-7. https://doi.org/10.1016/j.joms.2009.07.022   DOI
17 Zhu S, Wang D, Yin Q, Hu J. Treatment guidelines for temporomandibular joint ankylosis with secondary dentofacial deformities in adults. J Craniomaxillofac Surg 2013;41:e117-27. https://doi.org/10.1016/j.jcms.2012.11.038   DOI
18 Danda AK, S R, Chinnaswami R. Comparison of gap arthroplasty with and without a temporalis muscle flap for the treatment of ankylosis. J Oral Maxillofac Surg 2009;67:1425-31. https://doi.org/10.1016/j.joms.2008.12.049   DOI
19 Elgazzar RF, Abdelhady AI, Saad KA, Elshaal MA, Hussain MM, Abdelal SE, et al. Treatment modalities of TMJ ankylosis: experience in Delta Nile, Egypt. Int J Oral Maxillofac Surg 2010;39:333-42. https://doi.org/10.1016/j.ijom.2010.01.005   DOI
20 Shaikh SK, Mishra M, Tiwari AK, Chander M, Gaur A, Singh H. Comparative evaluation of gap arthroplasty and interpositional arthroplasty using temporalis fascia in the management of temporomandibular joint ankylosis. J Orofac Res 2013;3:170-4.
21 Bhatt K, Roychoudhury A, Bhutia O, Pandey RM. Functional outcomes of gap and interposition arthroplasty in the treatment of temporomandibular joint ankylosis. J Oral Maxillofac Surg 2014;72:2434-9. https://doi.org/10.1016/j.joms.2014.08.012   DOI
22 Bayat M, Badri A, Moharamnejad N. Treatment of temporomandibular joint ankylosis: gap and interpositional arthroplasty with temporalis muscle flap. Oral Maxillofac Surg 2009;13:207-12. https://doi.org/10.1007/s10006-009-0174-4   DOI
23 Guruprasad Y, Chauhan DS, Cariappa KM. A retrospective study of temporalis muscle and fascia flap in treatment of TMJ ankylosis. J Maxillofac Oral Surg 2010;9:363-8. https://doi.org/10.1007/s12663-010-0139-z   DOI
24 Rajan R, Reddy NV, Potturi A, Jhawar D, Muralidhar PV, Reddy B. Gap arthroplasty of temporomandibular joint ankylosis by transoral access: a case series. Int J Oral Maxillofac Surg 2014;43:1468-72. https://doi.org/10.1016/j.ijom.2014.08.010   DOI
25 Xia L, An J, He Y, Xiao E, Chen S, Yan Y, et al. Association between the clinical features of and types of temporomandibular joint ankylosis based on a modified classification system. Sci Rep 2019;9:10493. https://doi.org/10.1038/s41598-019-46519-8   DOI
26 Chossegros C, Guyot L, Cheynet F, Blanc JL, Gola R, Bourezak Z, et al. Comparison of different materials for interposition arthroplasty in treatment of temporomandibular joint ankylosis surgery: long-term follow-up in 25 cases. Br J Oral Maxillofac Surg 1997;35:157-60. https://doi.org/10.1016/s0266-4356(97)90554-4   DOI
27 Kim SG. Treatment of temporomandibular joint ankylosis with temporalis muscle and fascia flap. Int J Oral Maxillofac Surg 2001;30:189-93. https://doi.org/10.1054/ijom.2001.0047   DOI
28 Dimitroulis G. The interpositional dermis-fat graft in the management of temporomandibular joint ankylosis. Int J Oral Maxillofac Surg 2004;33:755-60. https://doi.org/10.1016/j.ijom.2004.01.012   DOI
29 He D, Yang C, Chen M, Zhang X, Qiu Y, Yang X, et al. Traumatic temporomandibular joint ankylosis: our classification and treatment experience. J Oral Maxillofac Surg 2011;69:1600-7. https://doi.org/10.1016/j.joms.2010.07.070   DOI
30 Braimah RO, Taiwo AO, Ibikunle AA, Oladejo T, Adeyemi M, Adejobi AF, et al. Temporomandibular joint ankylosis with maxillary extension: proposal for modification of Sawhney's classification. Craniomaxillofac Trauma Reconstr Open 2018;2:e15-21. https://doi.org/10.1055/s-0038-1666852   DOI
31 Tanrikulu R, Erol B, Gorgun B, Soker M. The contribution to success of various methods of treatment of temporomandibular joint ankylosis (a statistical study containing 24 cases). Turk J Pediatr 2005;47:261-5.
32 Ramezanian M, Yavary T. Comparion of gap arthroplasty and interpositional gap arthroplasty on the temporomandibular joint ankylosis. Acta Med Iran 2006;44:391-4.
33 Shakeel M, Imran M, Ahad B, Shafi M, Khan A. Surgical treatment of temporomandibular joint ankylosis: skims experience of 105 cases. Int J Med Res Health Sci 2016;5:77-82.
34 Zhi K, Ren W, Zhou H, Gao L, Zhao L, Hou C, et al. Management of temporomandibular joint ankylosis: 11 years' clinical experience. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:687-92. https://doi.org/10.1016/j.tripleo.2009.06.041   DOI
35 Holmlund A, Lund B, Weiner CK. Mandibular condylectomy with osteoarthrectomy with and without transfer of the temporalis muscle. Br J Oral Maxillofac Surg 2013;51:206-10. https://doi.org/10.1016/j.bjoms.2012.05.011   DOI
36 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. https://doi.org/10.1016/j.ijom.2013.07.745   DOI
37 Thangavelu A, Santhosh Kumar K, Vaidhyanathan A, Balaji M, Narendar R. Versatility of full thickness skin-subcutaneous fat grafts as interpositional material in the management of temporomandibular joint ankylosis. Int J Oral Maxillofac Surg 2011;40:50-6. https://doi.org/10.1016/j.ijom.2010.06.025   DOI
38 Malhotra VL, Singh V, Rao JD, Yadav S, Gupta P, Shyam R, et al. Lateral arthroplasty along with buccal fat pad inter-positioning in the management of Sawhney type III temporomandibular joint ankylosis. J Korean Assoc Oral Maxillofac Surg 2019;45:129-34. https://doi.org/10.5125/jkaoms.2019.45.3.129   DOI
39 Qudah MA, Qudeimat MA, Al-Maaita J. Treatment of TMJ ankylosis in Jordanian children - a comparison of two surgical techniques. J Craniomaxillofac Surg 2005;33:30-6. https://doi.org/10.1016/j.jcms.2004.07.005   DOI
40 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. https://doi.org/10.1007/s12663-014-0686-9   DOI
41 Loveless TP, Bjornland T, Dodson TB, Keith DA. Efficacy of temporomandibular joint ankylosis surgical treatment. J Oral Maxillofac Surg 2010;68:1276-82. https://doi.org/10.1016/j.joms.2009.10.014   DOI
42 Sahoo NK, Tomar K, Kumar A, Roy ID. Selecting reconstruction option for TMJ ankylosis: a surgeon's dilemma. J Craniofac Surg 2012;23:1796-801. https://doi.org/10.1097/SCS.0b013e318270fab5   DOI
43 Mercuri LG. Alloplastic temporomandibular joint replacement: rationale for the use of custom devices. Int J Oral Maxillofac Surg 2012;41:1033-40. https://doi.org/10.1016/j.ijom.2012.05.032   DOI
44 Balaji SM. Modified temporalis anchorage in craniomandibular reankylosis. Int J Oral Maxillofac Surg 2003;32:480-5.   DOI
45 Manganello-Souza LC, Mariani PB. Temporomandibular joint ankylosis: report of 14 cases. Int J Oral Maxillofac Surg 2003;32:24-9. https://doi.org/10.1054/ijom.2002.0308   DOI
46 Tang W, Long J, Feng F, Guo L, Gao C, Tian W. Condyle replacement after tumor resection: comparison of individual prefabricated titanium implants and costochondral grafts. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:147-52. https://doi.org/10.1016/j.tripleo.2009.01.028   DOI
47 Chen S, He Y, An JG, Zhang Y. Recurrence-related factors of temporomandibular joint ankylosis: a 10-year experience. J Oral Maxillofac Surg 2019;77:2512-21. https://doi.org/10.1016/j.joms.2019.06.172   DOI
48 Wolford LM, Morales-Ryan CA, Morales PG, Cassano DS. Autologous fat grafts placed around temporomandibular joint total joint prostheses to prevent heterotopic bone formation. Proc (Bayl Univ Med Cent) 2008;21:248-54. https://doi.org/10.1080/08998280.2008.11928404   DOI
49 Mercuri LG. Patient-fitted ("custom") alloplastic temporomandibular joint replacement technique. Atlas Oral Maxillofac Surg Clin North Am 2011;19:233-42. https://doi.org/10.1016/j.cxom.2011.05.001   DOI
50 Wolford LM, Karras SC. Autologous fat transplantation around temporomandibular joint total joint prostheses: preliminary treatment outcomes. J Oral Maxillofac Surg 1997;55:245-51; discussion 251-2. https://doi.org/10.1016/s0278-2391(97)90535-8   DOI
51 Wolford L, Movahed R, Teschke M, Fimmers R, Havard D, Schneiderman E. Temporomandibular joint ankylosis can be successfully treated with TMJ concepts patient-fitted total joint prosthesis and autogenous fat grafts. J Oral Maxillofac Surg 2016;74:1215-27. https://doi.org/10.1016/j.joms.2016.01.017   DOI
52 Zanaty O, El Metainy S, Abo Alia D, Medra A. Improvement in the airway after mandibular distraction osteogenesis surgery in children with temporomandibular joint ankylosis and mandibular hypoplasia. Paediatr Anaesth 2016;26:399-404. https://doi.org/10.1111/pan.12869   DOI
53 Gabbay JS, Heller JB, Song YY, Wasson KL, Harrington H, Bradley JP. Temporomandibular joint bony ankylosis: comparison of treatment with transport distraction osteogenesis or the Matthews device arthroplasty. J Craniofac Surg 2006;17:516-22. https://doi.org/10.1097/00001665-200605000-00022   DOI
54 Boyd SB. Management of obstructive sleep apnea by maxillo-mandibular advancement. Oral Maxillofac Surg Clin North Am 2009;21:447-57. https://doi.org/10.1016/j.coms.2009.09.001   DOI
55 Vijaya Krishnan P, Raghunandhan S, Anand Kumar RS, Kameswaran M. A rational approach to the management of obstructive sleep apnea syndrome. Indian J Otolaryngol Head Neck Surg 2014;66(Suppl 1):138-46. https://doi.org/10.1007/s12070-011-0381-9   DOI
56 Bouchard C, Troulis MJ, Kaban L. Management of obstructive sleep apnea: role of distraction osteogenesis. Oral Maxillofac Surg Clin North Am 2009;21:459-75. https://doi.org/10.1016/j.coms.2009.07.001   DOI
57 Flores RL. Neonatal mandibular distraction osteogenesis. Semin Plast Surg 2014;28:199-206. https://doi.org/10.1055/s-0034-1390173   DOI
58 Ching JA, Daggett JD, Alvarez SA, Conley CL, Ruas EJ. A simple mandibular distraction protocol to avoid tracheostomy in patients with Pierre Robin sequence. Cleft Palate Craniofac J 2017;54:210-5. https://doi.org/10.1597/14-211   DOI
59 Selbong U, Rashidi R, Sidebottom A. Management of recurrent heterotopic ossification around total alloplastic temporomandibular joint replacement. Int J Oral Maxillofac Surg 2016;45:1234-6. https://doi.org/10.1016/j.ijom.2016.02.017   DOI
60 ShanYong Z, Liu H, Yang C, Zhang X, Abdelrehem A, Zheng J, et al. Modified surgical techniques for total alloplastic temporomandibular joint replacement: one institution's experience. J Craniomaxillofac Surg 2015;43:934-9. https://doi.org/10.1016/j.jcms.2015.03.028   DOI
61 Wolford LM, Mercuri LG, Schneiderman ED, Movahed R, Allen W. Twenty-year follow-up study on a patient-fitted temporomandibular joint prosthesis: the Techmedica/TMJ Concepts device. J Oral Maxillofac Surg 2015;73:952-60. https://doi.org/10.1016/j.joms.2014.10.032   DOI
62 Shirani G, Mohammadi F, Arshad M, Shirazi M. Temporomandibular joint ankylosis: case-series of two different surgical procedures. Dent Hypotheses 2014;5:103-8. https://doi.org/10.4103/2155-8213.136754   DOI
63 Braimah R, Taiwo A, Ibikunle A, Oladejo T, Adeyemi M, Adejobi F, et al. Clinical experience in managing temporomandibular joint ankylosis: five-year appraisal in a Nigerian subpopulation. J Korean Assoc Oral Maxillofac Surg 2018;44:112-9. https://doi.org/10.5125/jkaoms.2018.44.3.112   DOI
64 Park MW, Eo MY, Seo BY, Nguyen TTH, Kim SM. Gap arthroplasty with active mouth opening exercises using an interocclusal splint in temporomandibular joint ankylosis patients. Maxillofac Plast Reconstr Surg 2019;41:18. https://doi.org/10.1186/s40902-019-0200-x   DOI
65 Lin CL, Kuo YC, Lo LJ. Design, manufacture and clinical evaluation of a new TMJ exerciser. Biomed Eng 2005;17:135-40. https:// doi.org/10.4015/S1016237205000214   DOI
66 Roychoudhury A, Parkash H, Trikha A. Functional restoration by gap arthroplasty in temporomandibular joint ankylosis: a report of 50 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;87:166-9. https://doi.org/10.1016/s1079-2104(99)70267-2   DOI
67 Tahiri Y, Viezel-Mathieu A, Aldekhayel S, Lee J, Gilardino M. The effectiveness of mandibular distraction in improving airway obstruction in the pediatric population. Plast Reconstr Surg 2014;133:352e-9e. https://doi.org/10.1097/01.prs.0000438049.29258.a8   DOI
68 Ma Y, Huang Y, Zhu S, Li Y. Simultaneous arthroplasty and distraction osteogenesis for the treatment of ankylosis of the temporomandibular joint and secondary mandibular deformities in children. Br J Oral Maxillofac Surg 2019;57:135-9. https://doi.org/10.1016/j.bjoms.2018.11.016   DOI
69 Mehrotra D, Vishwakarma K, Chellapa AL, Mahajan N. Prearthroplasty simultaneous maxillomandibular distraction osteogenesis for the correction of post-ankylotic dentofacial deformities. Int J Oral Maxillofac Surg 2016;45:820-7. https://doi.org/10.1016/j.ijom.2015.10.009   DOI
70 Anchlia S, Vyas SM, Dayatar RG, Domadia HL, Nagavadiya V. Guidelines for single-stage correction of TMJ ankylosis, facial asymmetry and OSA in adults. J Maxillofac Oral Surg 2019;18:419-27. https://doi.org/10.1007/s12663-018-1121-4   DOI
71 El-Hakim IE, Metwalli SA. Imaging of temporomandibular joint ankylosis. A new radiographic classification. Dentomaxillofac Radiol 2002;31:19-23. https://doi.org/10.1038/sj/dmfr/4600660   DOI
72 Babu L, Jain MK, Ramesh C, Vinayaka N. Is aggressive gap arthroplasty essential in the management of temporomandibular joint ankylosis?-a prospective clinical study of 15 cases. Br J Oral Maxillofac Surg 2013;51:473-8. https://doi.org/10.1016/j.bjoms.2012.11.004   DOI
73 Sawhney CP. Bony ankylosis of the temporomandibular joint: follow-up of 70 patients treated with arthroplasty and acrylic spacer interposition. Plast Reconstr Surg 1986;77:29-40.   DOI
74 Sharma R, Manikandhan R, Sneha P, Parameswaran A, Kumar JN, Sailer HF. Neocondyle distraction osteogenesis in the management of temporomandibular joint ankylosis: report of five cases with review of literature. Indian J Dent Res 2017;28:269-74. https://doi.org/10.4103/ijdr.IJDR_292_13   DOI
75 Saeed NR, McLeod NM, Hensher R. Temporomandibular joint replacement in rheumatoid-induced disease. Br J Oral Maxillofac Surg 2001;39:71-5. https://doi.org/10.1054/bjom.2000.0565   DOI
76 Ma J, Liang L, Jiang H, Gu B. Gap arthroplasty versus interpositional arthroplasty for temporomandibular joint ankylosis: a metaanalysis. PLoS One 2015;10:e0127652. https://doi.org/10.1371/journal.pone.0127652   DOI
77 Kazanjian VH. Ankylosis of the temporomandibular joint. Am J Orthod Oral Surg 1938;24:1181-206. https://doi.org/10.1016/S0096-6347(38)90337-0   DOI
78 Topazian RG. Comparison of gap and interposition arthroplasty in the treatment of temporomandibular joint ankylosis. J Oral Surg 1966;24:405-9.
79 Durr ED, Turlington EG, Foote RL. Radiation treatment of heterotopic bone formation in the temporomandibular joint articulation. Int J Radiat Oncol Biol Phys 1993;27:863-9.   DOI