Orthognathic and Orthodontic Treatments for TMJ-osteoarthritis with Jaw Deformity

Orthognathic and Orthodontic Treatments for TMJ-osteoarthritis with Jaw Deformity Eiji TANAKA, DDS, PhD 1, Shinya HORIUCHI, DDS, PhD 2 and Shingo KURODA, DDS, PhD 3 Introduction TMJ disorders TMDs as reported in the early dental literature 1 3 and by Costen 4 in the early medical literature, first promoted TMJ anatomical misalignment as a new and separate source of facial pain. Nowadays, TMDs are characterized by intra-articular morphologic abnormalities, such as traumatic, degenerative and/or inflammatory arthritic pathology, and developmental, congenital and neoplastic processes. A review of 18 epidemiologic studies published in the 1980s reported prevalence rates ranging from 16 to 59 for reported symptoms and 33 to 86 for clinical signs 5, although 3 to 7 of the adult population have sought care for TMD-related pain and dysfunction 6. The most common joint pathology affecting the TMJ is degenerative joint disease, also known as osteoarthrosis or osteoarthritis OA. Mejersjö, et al. 7 reported that 11 of 93 TMD patients had symptoms of TMJ-OA, whereas 50 of the joints 71 of the patients revealed radiographic signs of TMJ structural changes. Furthermore, an epidemiological study, using cephalometrically corrected tomograms, showed that minimal flattening of the condyle and/or eminence was seen in 35 of TMJs in asymptomatic persons no internal derangement 8. More advanced osseous changes were not seen, therefore, it was concluded that minimal flattening was probably of no clinical significance. However, once the breakdown in the joint starts, TMJ-OA can be crippling, leading to a variety of morphological and functional deformities 9. Increased awareness and interest in TMDs, while part of a general trend in dentistry, represents a change in emphasis in orthodontics toward treating more adults 10. At present, more than 30 of all orthodontic patients are adults. By enlarging the scope of their treatment population, orthodontists have already been treating patients who are part of the group most likely to suffer from TMDs. Therefore, orthodontics is part of the interdisciplinary TMJ care team. This paper outlines some basic concepts in the management of TMJ-OA. We propose an orthodontic approach to TMJ- OA from our own clinical experiences, which shows the potential of orthodontics to contribute to TMJ-OA managements. Definition and etiology of TMJ-OA Unlike rheumatoid arthritis, TMJ-OA has a noninflammatory origin 9. The pathological process is characterized by deterioration and abrasion of articular cartilage and local thickening and remodeling of the underlying bone 9. These changes are frequently accompanied by the superimposition of secondary inflammatory changes. Therefore, mechanicallyinduced OA may better reflect TMJ-OA. It was suggested that OA may be a final common pathway for several joint conditions, including inflammatory, endocrine, metabolic, developmental and biomechanical disorders 9. Typical symptoms in TMJ- OA patients are crepitus, TMJ pain, and restriction of mandibular movements, especially mouth opening movement. The characteristic radiographic sign of TMJ-OA is dysfunctional remodeling on the mandibular condyle and articular eminence surfaces with osteophyte formation. OA has been generally regarded as inevitably progressive once it has become clinically symptomatic.

Fig. 1 Schematic illustration of the concept of mandibular condylar resorption. TMJ-OA is initiated from mandibular condylar cartilage degradation. Fig. 1 shows a schematic illustration of the concept of mandibular condylar cartilage degradation 11, 12. Under normal conditions, functional loading in the TMJ is essential to functional bone remodeling and metabolism. This loading is absolutely necessary for growth, development and maintenance of the TMJ. However, if the loading is excessive or abnormal, or if the host adaptive capacity decreases due to aging and systematic disease, functional overloading can facilitate hypoxia in the TMJ which mediates the destructive processes associated with OA as an autocrine factor. The induction of vascular endothelial growth factor VEGF in OA-cartilage by functional overloading is linked to activation of the hypoxia-inducing factor, HIF-1, leading to hypoxia in the joint tissue 13 15. Furthermore, VEGF regulates the production of MMPs and TIMPs which are among the effectors of extracellular matrix remodeling. Overloading also causes collapse of joint lubrication as a result of the degradation of hyaluronic acid by free radicals 12. The regulation of hyaluronic acid production is controlled by various pro-inflammatory cytokines. As a result, TMJ overloading is one of the key factors in the onset and progression of OA. Functional overloading can lead to physical disruption of cells, impaired cellular function, transient ischemia of cell population and neurogenic irritants 16. As a result, joint tissues may collapse Fig. 2. If the collapse occurs in one side of the TMJ, the mandible shifts laterally, resulting in mandibular asymmetry. If the collapse occurs in both TMJs, condylar resorption produces morphologic collapse of the TMJ component and a subsequent decrease in the ramus height, resulting in progressive mandibular retrusion with anterior open bite. Management of TMJ-OA Management of TMJ-OA may be divided into noninvasive, minimally invasive, invasive or surgical modalities, and salvage modalities in end-stage disease. The decision to surgically manage any TMJ arthritic condition must be based on an evaluation of the patient s response to non-invasive management, the patient s mandibular form and function, and the effect the condition has on the patient s quality of life 17. The management goals in TMJ-OA should be: 1. Decreasing joint pain, swelling and reflex masticatory muscle spasm/pain 2. Increasing joint function 3. Preventing further joint damage 4. Preventing disability and disease related morbidity Using a classification scheme based on clinical signs

Fig. 2 Samples of MR images in severe TMJ-OA patients: Condylar re sorption and avascular necrosis. and symptoms and imaging, modified from that developed by Steinbrocker, et al. 18 and Kent, et al. 19, this paper presents an evidence-based discussion on the management of TMJ-OA. 1. Non-invasive management modalities 1 Occlusal splint In the clinic, occlusal splints are the most common method of treating pain associated with the TMJ. Occlusal splints are an effective device to protect the TMJ from involuntary overloading, and to reduce the muscle hyperactivity and articular strain due to bruxism. In a controlled study on the effects of occlusal splint therapy in individuals with severe TMJ-OA, a reduction of clinical signs was seen 20. However, a critical evaluation of splint therapy has not yet been conducted due to a lack of evidence, and its clinical effectiveness in relieving pain seems modest compared with that of pain treatment methods in general 21. None of the occlusal adjustment studies provided evidence supporting the use of this treatment method. 2 Medications Non-steroidal anti-inflammatory NSAID agents such as ibuprofen should be used on a time contingent basis to take advantage of their pharmacokinetics. Muscle relaxants may be helpful to control the reflex masticatory muscle spasm/pain 22. 3 Orthotics Oral orthotics, while assisting in the control of parafunctional habits in many patients, also can provide relief from masticatory muscle spasm/pain and, along with a soft diet, will decrease the loads delivered across the TMJ articulation under function. 4 Physical therapy Physical therapeutic modalities act as counter irritants to reduce inflammation and pain. Superficial warm and moist heat or localized cold may relieve pain sufficiently to permit exercise. Therapeutic exercises are designed to increase muscle strength, reduce joint contractures and maintain a functional range of motion. Active and passive jaw movements, manual therapy techniques, and relaxation techniques were used in the management of 20 consecutive TMJ-OA patients. After treatment mean 46 days, pain at rest was reduced by 80 and there was no impairment in 37 of cases 23. 2. Minimally invasive modalities 1 Hyaluronate HA HA, comprising 0.14 0.36 of synovial fluid in normal subjects 24, is one of the principal components determining its rheological properties. It has been

demonstrated that injection of HA into joints improves mobility and suppresses pain and inflammation 25, 26. In double blind studies in other joints after 2 months, HA has been shown to provide significantly better results than saline 27, 28. These results were sustained for 1 year. However, the effectiveness of HA injection into the TMJ remains controversial, and so HA has not yet been approved as a safe and effective medication in the management of arthritic disease in the TMJ by the United States Food and Drug Administration. 2 Corticosteroids Intra-articular injections of corticosteroids are of limited use in other joints of the body 29. The main limitations of repeated intra-articular steroid injections are the risks of infection and the destruction of articular cartilage, tendon or ligament attachments. Repeated intra-articular corticosteroid injections have been implicated in the chemical condylectomy phenomenon in the TMJ 30, 31. 3 Arthrocentesis Nitzan, et al. 32 demonstrated that arthrocentesis is a rapid and safe procedure that may result in the TMJ-OA returning to a functional state. Failure of arthrocentesis 32 suggested that painful limitation of TMJ function might be the result of fibrous adhesions or osteophytes that require arthrotomy for management. 4 Arthroscopy The value of TMJ arthroscopy may be in the early diagnosis and management of arthritic processes affecting the TMJ, especially early-stage arthritic disease, to avoid the complications of open bite and ankylo - sis 33, 34. However, late-stage marked fibrosis or ankylosis makes arthroscopy impossible and contra indicates its usefulness. 3. Invasive surgical modalities Bone and joint procedures 1 Arthroplasty Henny, et al. 35 described this procedure high condylar shave as a limited removal of the damaged articular surface of the condyle, which maintains the height of the ramus, the articular disc and the surrounding soft tissue including the lateral pterygoid muscle attachment. Its use was advocated in cases with severe, unremitting OA pain. 2 Autogenous hemiarthroplasty A number of different autogenous tissues have been advocated as a replacement for the TMJ disc 36, however, the literature on the use of the vascularized local temporalis muscle flap appears to present the most applicable data to the management of the arthritic TMJ 36 38. 3 Osteotomy Although successful outcomes have been reported using orthognathic surgical procedures to manage maxillofacial skeletal discrepancies with signs and symptoms of TMD 39, the treatment outcomes after orthognathic surgery depend on the presurgical TMJ condition. Patients with active TMJ disease and either concomitant or resultant maxillofacial skeletal discrepancies, treated only with orthognathic surgery, often have poor outcomes and significant relapse 40 45. This implies that patients with presurgical TMJ symptoms requiring mandibular advancement appear to be at increased risk of condylar resorption. Pre-existing TMJ pathologies, with or without symptoms that can lead to unfavorable orthognathic surgery outcomes, include: internal derangements, progressive condylar resorption, condylar hyperplasia, osteochondroma, congenital deformities, and non-salvageable joints 44. Since the TMJs are the foundation of orthognathic surgery, the resultant pathology offers a poor base upon which to build any maxillofacial functional and skeletal reconstruction in conditions where there are gross erosive changes in the articulating components of both the fossa and condyle resulting in loss of vertical height. Furthermore, the degenerative and osteolytic changes that the joint components are undergoing in these conditions make these components of the TMJ highly susceptible to failure under the new functional loading resulting from orthognathic surgical repositioning of the maxillofacial skeleton. Meanwhile, Wolford, et al. 46 reported 12 young patients with active idiopathic condylar resorption who underwent combined TMJ disc repositioning and stabilization with the Mitek anchor Mitek Surgical Products Inc., Westwood, MA and bimaxillary orthognathic surgery followed for 33 months with stable skeletal and occlusal results as well as significant pain relief. Morales-Ryan, et al. 47 also evaluated 44 young idiopathic condylar resorption patients, 10 of whom underwent bimaxillary orthognathic surgery but no TMJ surgery and 34 of whom underwent the management recommended by Wolford, et al. 46. The former 10 patients followed for 37 months were

reported as having statistically significant relapse due to progressive condylar resorption, whereas the other 34 patients followed for 25.5 months had no statistically significant relapse due to progressive condylar resorption. Recently, Goncalves, et al. 48 reported 35 patients with degenerative joint disease who underwent combined TMJ disc repositioning and stabilization with the Mitek anchor and orthognathic surgery followed for 31 months with stable skeletal and occlusal results as well as significant pain relief, while 16 patients with preoperative TMJ disc displacement who underwent double-jaw surgery and no TMJ intervention experienced significant relapse. Taken together, maxillomandibular advancement with counterclockwise rotation of the occlusal plane is a stable procedure for patients with healthy TMJs and for patients undergoing simultaneous TMJ disc repositioning using the Mitek anchor technique. However, the patients who had presurgical TMJ symptoms but underwent only orthognathic surgery demonstrated a statistically significant rate of skeletal relapse related to condylar remodeling and resorption. In Japan, surgical disc-repositioning using the Mitek anchor technique is not popular compared with in America. Therefore, orthognathic surgery is not strongly recommended for patients with progressive mandibular retrusion involved in TMJ-OA. 4 Osseodistraction Van Strijen, et al. 49 reported a case of idiopathic condylar resorption 1 year following distraction osteogenesis to advance the mandible in a 15-year-old male. While there was associated post-distraction trauma in this case, the authors advised that since osteoclastic activity in the TMJ has been reported after gradual distraction of the mandible, distraction osteogenesis may make its own contribution to TMJ-OA and idiopathic condylar resorption. Van Strijen, et al. 49 suggested that in the future, patients being considered for surgical management of mandibular hypoplasia should be critically evaluated for any traumatic, functional or metabolic risk factors for OA and condylar resorption. Based on the experience reported in the literature, it is recommended that maxillofacial skeletal discrepancies resulting from active or advanced arthritic TMJ disease should be most predictably managed utilizing the orthopedic principles of total joint replacement, which has been safely and effectively used for over four decades in other joints for these conditions. 4. Salvage procedures - total joint replacement In the TMJ, alloplastic reconstruction has been discussed at length 50, 51. All of these authors agree that when the mandibular condyle is extensively damaged, degenerated or lost, as in arthritic conditions, replacement with either autogenous graft or alloplastic implant is an acceptable approach to achieve optimal symptomatic and functional improvement. Long-term follow-up studies have included patients with diagnoses consistent with low- and high-inflammatory arthritic TMJs in their total alloplastic reconstruction datasets 17, 52 55. At present, based on the available published clinical data, alloplastic TMJ reconstruction may be most successful for the reconstruction of patients with high-inflammatory TMJ arthritis, for management of reankylosis and loss of posterior mandibular vertical dimension as the result of pathology, or for ablative mandibular surgery in adults. Orthodontic approach to TMJ-OA By using orthognathic surgery, maxillomandibular advancement with counterclockwise rotation in skeletal mandibular retrusion and the resultant anterior open bite can provide significant improvements in both occlusion and facial esthetics. However, as described above, orthognathic surgery might not improve TMD in patients with active TMD symptoms. In addition, orthognathic surgery requires surgical invasion with postoperative discomfort and risks. It is true that morphologic collapse of the joint component by TMJ-OA induces a decrease in the ramus height, leading to a clockwise rotation of the mandible and anterior open bite. These characteristics appear to cause TMJ overloading. From the results of finite element model analysis, the open bite condition can induce larger stress in the TMJ compared with normal occlusion 56. Furthermore, clockwise rotation of the mandible, which is a main characteristic of skeletal open bite, leads to a synergistic increase of the TMJ stress during clenching 56. This indicates that improvement of mandibular clockwise rotation may be essential for the treatment of acquired open bite with TMJ-OA, resulting in the reduction of TMJ overloading. Kuroda, et al. 57, 58 reported that molar intrusion using implant anchorage was quite useful to improve both

Fig. 3 Treatment mechanism for mandibular retrusion with anterior open bite involved in condylar resorption. occlusion and facial esthetics in severe anterior open bite patients with a skeletal Class II jaw relationship, because of mandibular counterclockwise rotation and the resultant relatively forward movement of the mandible. In their case reports, the mandibular plane was rotated more than 5 by the molar intrusion, nevertheless the patients after orthodontic treatment did not have any functional problems. These procedures are far less invasive for the patient than a LeFort I osteotomy for maxillary impaction or a mandibular set-forward osteotomy. Therefore, we suggest orthodontic treatment for patients with OA-associated condylar resorption and either concomitant or resultant maxillofacial skeletal discrepancies such as mandibular retrusion and anterior open bite with molar intrusion, which not only has a beneficial effect on esthetic appearance and occlusion, but also results in TMJ improvement Fig. 3. As a result of counterclockwise rotation of the mandible caused by molar intrusion, the condyle is repositioned, and functional adaptation in circumoral musculature can be achieved. However, it has been difficult to achieve these skeletal improvements by traditional orthodontic mechanics 59 61. Treatment with implant anchorage for molar intrusion might become a new therapeutic approach for anterior open bite patients with TMD. In our experience, long-term follow-up at least 5 years after orthodontic treatment confirmed no or minimal relapse of mandibular clockwise rotation and anterior open bite and recurrences of TMD symptoms. Conclusions Growing evidence suggests that like OA in other joints, overloading may be assumed to be an initiating factor for a series of degenerative changes in the TMJ- OA, such as condylar resorption, the subsequent decrease in mandibular ramus height, mandibular clockwise rotation, progressive mandibular retrusion, and anterior open bite. To date, many treatment modalities for TMJ-OA have been reported, while the treatment outcomes depend on the preoperative TMJ conditions. Therefore, it is essential to understand the pathogenesis of TMJ-OA and current clinical treatment to develop a good as new treatment remedy for TMJ- OA, including the orthodontic approach. References 1 Wright, W.H.: Deafness as influenced by malposition of the jaws, J Natl Dent Assoc, 7 979 992, 1920. 2 Monson, G.S.: Occlusion as applied to crown and bridge work, J Natl Dent Assoc, 7 399 413, 1920. 3 Gysi, A. : Studies on the leverage problem of the mandible, Dent Digest, 27 74 84, 144 150, 203 208, 1921. 4 Costen, J.B.: A syndrome of ear and sinus symp-

toms dependent upon disturbed function of the temporomandibular joint, Ann Otol Rhinol Laryngol, 43 1 15, 1934. 5 Carlsson, G.E., et al. : Epidemiology of temporomandibular disorders. In: Temporomandibular Disorders and Related Pain Conditions Sessle BJ, Bryant PS, Dionne RA, eds.. Seattle: Seattle Press, 1995. 6 Carlsson, G.E. : Epidemiology and treatment need for temporomandibular disorders, J Orofac Pain, 13 232 237, 1999. 7 Mejersjö, C., et al.: Radiography of the temporomandibular joint in the mandibular joint in female patients with TMJ pain or sysfunction, Acta Radiol, 25 169 174, 1984. 8 Brooks, S.L., et al.: Prevalence of osseous changes in the temporomandibular joint of asymptomatic persons without internal derangement, Oral Surg Oral Med Oral Pathol, 73 118 122, 1992. 9 Zarb, G.A., et al. : Temporomandibular disorders: Osteoarthritis, J Orofac Pain, 12 295 306, 1999. 10 Solberg, W.K.: Current concepts on the development of TMJ dysfunction. In : Developmental Aspects of Temporomandibular Joint Disorders Carlson DS, McNamara JA, Ribbens KA, eds.. Michigan : Center for Human Growth and Development, pp 37 47, 1989. 11 Kuroda, S., et al.: Biomechanical and biochemical characteristics of the mandibular condylar cartilage, Osteoarthritis Cartilage, 17 1408 1415, 2009. 12 Tanaka, E., et al.: Degenerative disorders of the Temporomandibular Joint: Etiology, diagnosis, and treatment, J Dent Res, 87 296 307, 2008. 13 Aoyama, J., et al.: Immunolocalization of vascular endothelial growth factor in rat condylar cartilage during postnatal development, Histochem Cell Biol, 122 35 40, 2004. 14 Shirakura, M., et al. : Activation of the hypoxiainducible factor-1 in overloaded temporomandibular joint, and induction of osteoclastogenesis, Biochem Biophys Res Commun, 393 800 805, 2010. 15 Tanaka, E., et al.: Vascular endothelial growth factor plays an important autocrine/paracrine role in the progression of osteoarthritis, Histochem Cell Biol, 123 275 281, 2005. 16 Arnett, G.W., et al.: Progressive mandibular retrusion-idiopathic condylar resorption. Part I, Am J Orthod Dentofacial Orthop, 110 8 15, 1996. 17 Mercuri, L.G.: Surgical management of TMJ arthritis. In: TMDs, An Evidence-Based Approach to Diagnosis and Treatment Laskin DM, Greene CS, Hylander WL, eds.. Chicago: Quintessence, pp 455 468, 2006. 18 Steinbrocker, O., et al.: Therapeutic criteria in rheumatoid arthritis, JAMA,140 659 662, 1949. 19 Kent, J.N., et al.: Experience with polymer glenoid fossa prosthesis for partial or total temporomandibular joint reconstruction, J Oral Maxillofac Surg, 44 520 533, 1986. 20 Kuttila, M., et al. : Efficiency of occlusal appliance therapy in secondary otalgia and temporomandibular disorders, Acta Odontol Scnad, 60 248 254, 2002. 21 Forssell, H., et al.: Application of principles of evidence-based medicine to occlusal treatment for temporomandibular disorders: are there lessons to be learned? J Orofac Pain, 18 9 22, 2004. 22 Dionne, R.A. : Pharmacologic Approaches. In: TMDs, An Evidence-Based Approach to Diagnosis and Treatment Laskin DM, Greene CS, Hylander WL, eds.. Chicago: Quintessence, pp 347 357, 2006. 23 Nicolakis, P., et al.: An investigation of the effectiveness of exercise and manual therapy in treating symptoms of TMJ osteoarthritis, Cranio, 19 26 32, 2001. 24 Sundblad, L.: Glycosaminoglycans and glycoproteins in synovial fluid. In: The amino sugars. The chemistry and biology of compounds containing amino sugars Balazs EA, Jeanloz RW, eds.. New York, Academic Press, pp 229 250, 1965. 25 Wobig, M., et al.: The role of elastoviscosity in the efficacy of viscosupplementation for osteoarthritis of the knee: a comparison of hylan G-F 20 and a lower-molecular-weight hyaluronan, Clin Ther, 21 1549 1562, 1999. 26 Mabuchi, K., et al.: Molecular weight independence of the effect of additive hyaluronic acid on the lubricating characteristics in synovial joints with experimental deterioration, Clin Biomech, 14 352 356, 1999. 27 Dougados, M., et al.: High molecular weight sodium hyaluronate Hyalectin in osteoarthritis of the knee: a 1 year placebo-controlled trial, Osteoarthritis Cartilage, 1 97 103, 1993. 28 Lohmander, L.S., et al.: Intra-articular hyaluronan injections in the treatment of osteoarthritis on the knee: a randomized, double blind, placebo controlled trial. Hyaluronan Multicentre Trial Group, Ann Rheum Dis, 55 424 431, 1996. 29 Gray, R.G., et al.: Intra-articular corticosteroids. An updated assessment, Clin Orthop Relat Res, 177 235 263, 1983. 30 Moskowitz, R., et al.: Experimentally induced corticosteroid arthropathy, Arthritis Rheum, 13 236 243, 1970. 31 Toller, P.: Use and misuse of intra-articular corticosteriods in the treatment of TMJ pain, Proc Soc Med, 70 461 463, 1977. 32 Nitzan, D.W., et al.: The use of arthrocentesis for the treatment of osteoarthritic temporomandibular joints, J Oral Maxillofac Surg, 59 1154 1159, 2001. 33 Gynther, G.W., et al.: Efficacy of arthroscopic lysis and lavage in patients with temporomandibular joint symptoms associated with generalized osteoarthritis or rheumatoid arthritis, J Oral Maxillofac Surg, 56 147 151, 1998.

34 Murakami, K.: Arthroscopy of the temporomandibular joint. In : Modern Practice in Orthognathic and Reconstructive Surgery Bell WH, ed.. Philadelphia: Saunders Co., pp 608 617, 1992. 35 Henny, F.A., et al. : Condylectomy for the persistently painful temporomandibular joint, J Oral Surg, 15 24 31, 1957. 36 Albert, T.W., et al.: Temporalis muscle flap for reconstruction of the temporomandibular joint, Oral Maxillofac Clin NA, 1 341 349, 1989. 37 Brusati, R., et al. : The temporalis muscle flap in temporomandibular joint surgery, J Craniomaxillofac Surg, 18 352 358, 1990. 38 Pogrel, M.A., et al.: The role of a temporalis fascia and muscle flap in temporomandibular joint surgery. J Oral Maxillofac Surg, 48 14 19. 1990. 39 Magnusson, T., et al.: Function of the masticatory system in 20 patients with mandibular hypo- or hyperplasia after correction by a sagittal split osteotomy, Int J Oral Maxillofac Surg, 19 289 293, 1990. 40 Kerstens, H.C., et al.: Condylar atrophy and osteoarthrosis after bimaxillary surgery, Oral Surg Oral Med Oral Pathol, 69 274 280, 1990. 41 Crawford, J.G., et al.: Stability after reoperation for progressive condylar resorption after orthognathic surgery : report of seven cases, J Oral Maxillofac Surg, 52 460 466, 1994. 42 De Clercq, C.A., et al.: Condylar resorption in orthognathic surgery: a retrospective study, Int J Adult Orthod Orthognath Surg, 9 233 240, 1994. 43 Moore, K.E., et al.: The contributing role of condylar resorption to skeletal relapse following mandibular advancement surgery: report of five cases, J Oral Maxillofac Surg, 49 448 460, 1991. 44 Wolford, L.M., et al. : Temporomandibular joint reconstruction of the complex patient with the Techmedica custom-made total joint prosthesis, J Oral Maxillofac Surg, 52 2 10, 1994. 45 Wolford, L.M., et al.: Changes in temporomandibular joint dysfunction after orthognathic surgery, J Oral Maxillofac Surg, 61 655 660, 2003. 46 Wolford, L.M., et al.: Idiopathic condylar resorption: diagnosis, treatment protocol, and outcomes, Am J Orthodont Dentofacial Orthop, 116 667 677, 1999. 47 Morales-Ryan, C.A., et al. : Idiopathic condylar resorption: Outcome assessment of TMJ disc repositioning and orthognathic surgery, J Oral Maxillofac Surg, 60 S53, 2002. 48 Goncalves, J.R., et al.: Postsurgical stability of counterclockwise maxillomandibular advancement surgery : Affect of articular disc repositioning, J Oral Maxillofac Surg, 66 724 738, 2008. 49 van Strijen, P.J., et al.: Condylar resorption following distraction osteogenesis: a case report, J Oral Maxillofac Surg, 59 1104 1107, 2001. 50 Donlon, W.C.: Total Temporomandibular Joint Reconstruction. Oral Maxillofac Surg Clin NA vol. 12, Philadelphia, Saunders Co., 2000. 51 McBride, K.L. : Total temporomandibular joint reconstruction. In : Controversies in Oral and Maxillofacial Surgery Worthington P, Evans JR, eds.. Philadelphia : Saunders Co., pp 381 396, 1994. 52 Mercuri, L.G., et al.: Long-term follow-up of the CAD/CAM patient fitted total temporomandibular joint reconstruction system, J Oral Maxillofac Surg, 60 1440 1448, 2002. 53 Mercuri, L.G., et al.: Long-term outcomes after total alloplastic temporomandibular joint reconstruction following exposure to failed materials, J Oral Maxillofac Surg, 62 1088 1096, 2004. 54 Mercuri, L.G.: A rationale for total alloplastic temporomandibular joint reconstruction in the management of idiopathic/progressive condylar resorption, J Oral Maxillofac Surg, 65 1600 1609, 2007. 55 Mercuri, L.G., et al.: Considerations for the use of alloplastic temporomandibular joint replacement in the growing patient, J Oral Maxillofac Surg, 67 1979 1990, 2009. 56 Tanaka, E., et al.: Influences of occlusal and skeletal discrepancies on biomechanical environment in the TMJ during maximum clenching : an analytic approach with the finite element method, J Oral Rehabil, 28 888 894, 2001. 57 Kuroda, S., et al. : Severe anterior open-bite case treated using titanium screw anchorage, Angle Orthod, 74 558 567, 2004. 58 Kuroda, S., et al.: Anterior open bite with temporomandibular disorder treated with titanium screw anchorage : evaluation of morphological and functional improvement, Am J Orthod Dentofacial Orthop, 131 550 560, 2007. 59 Kuroda, S., et al.: Long-term stability of conservative orthodontic treatment in a patient with rheumatoid arthritis and severe condylar resorption, Am J Orthod Dentofacial Orthop, 141 352 362, 2012. 60 Tanaka, E., et al. : An adult case of TMJ osteoarthrosis treated with splint therapy and the subsequent orthodontic occlusal reconstruction: adaptive change of the condyle during the treatment, Am J Orthod Dentofacial Orthop, 118 566 571, 2000. 61 Tanaka, E., et al.: An adult case of skeletal open bite with a large lower anterior facial height, Angle Orthod, 75 465 471, 2005.