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Calcium pyrophosphate dihydrate deposition disease of the temporomandibular joint
Calcium pyrophosphate dihydrate deposition disease of the temporomandibular joint A case report and review of the literature Bruce R Pynn, MSc, DDS, a Simon Weinberg, DDS, FRCD(C), b and Jonathan Irish, MD, FRCS(C), c Toronto, Ontario, Canada THE TORONTO HOSPITAL AND UNIVERSITY OF TORONTO
An asymptomatic preauricular swelling in a 58-year-old man appeared as a parotid mass and was diagnosed as calcium pyrophosphate dihydrate crystal deposition disease of the temporomandibular joint. This article describes the diagnostic criteria and management of this rare condition and reviews the 13 cases that have been reported to date. (O~ALSURGO~At MED ORALPATHOLORALRADIOLENDOD1995;79:278414)
The deposition of calcium pyrophosphate dihydrate (CPPD) crystals seems to have a definite predilection for fibrocartilage rather than hyaline cartilage. 1 Therefore it is surprising that the temporomandibular joint (TMJ), a joint in which fibrocartilage rather than hyaline cartilage predominates, is so rarely affected by CPPD deposition disease. The occurrence of CPPD arthropathy of the TMJ is uncommon, and to our knowledge only thirteen cases of this condition have been reported. This article adds, an additional case report to the literature and tabulates the pertinent, clinical, and radiographic features of all reported cases, lq2 Zitnan and Sitaj first described CPPD arthropathy as a specific disease entity in 1958.13 They applied the term chondrocalcinosis to the characteristic radiographic appearance of linear punctate calcifications within the fibrocartilaginous meniscus of the knee joint. Because of the high concentration of CPPD crystals rather than urate crystals within the synovial fluid of patients with gout-like symptoms, Kohn et al. 14 suggested the term pseudogout to describe this condition. The significance of phosphate crystals in the synovial fluid of arthritic patients was described by McCarty et al. 15 in 1962. As CPPD crystals deposition may present a large spectrum of clinical manifestations, Ryan and McCarty 16 proposed the name calcium pyrophosphate dihydrate (CPPD) deposition disease as a more general term. aSenior Resident, Division of Oral and Maxillofacial Surgery, The Toronto Hospital and Faculty of Dentistry, University of Toronto. bprofessor, Division of Oral and Maxillofacial Surgery, The Toronto Hospital and Faculty of Dentistry, University of Toronto. CAssistant Professor, Department of Otolaryngology/Head and Neck Program, The Toronto Hospital and Faculty of Medicine,
Universityof Toronto. Copyright9 1995 by Mosby-YearBook, Inc. 1079-2104/95/$3.00 + 0 7/12/60302 278
The salient clinical and radiographic features of the reported cases of CPPD crystal deposition disease involving the T M J have been tabulated (Table I). Crystal deposition in CPPD favors fibrocartilage, and the knee has been involved in more than 50% of the reported studies that document chondrocalcinosis.2 One would therefore anticipate that the TMJ would be a regular site of crystal deposition because its articular surfaces and articular disk are comprised entirely of fibrocartilage. Pritzker et al. 3 were the first to describe CPPD crystal deposition disease in the TMJ. They postulated that the paucity of reports in the literature may be due to the lack of clinical distinction between the arthritides and other causes of T M J pain, infrequent investigations into the nature of the pathologic joint, and the peculiar anatomy of the TMJ. Although there is currently no satisfactory explanation, the TMJ remains an unusual location of crystal-induced synovitis. The following diagnostic criteria have been established by Resnick et a1.17 for CPPD crystal deposition disease: CPPD crystals are detected in the fibrocartilage of a joint by electron microscopy or x-ray diffraction; crystals compatible with CPPD are found with the use of polarized light; and the patient has a diagnostic radiographic pattern. If only one of these criteria is present, a diagnosis of probable but not definitive chondrocalcinosis is made. CPPD deposition disease occurs more often in women with an increasing incidence beyond the fifth decade of life. l, 4 Various predisposing factors have been associated with CPPD crystal deposition disease, and these include hyperparathyroidism, hypercalcemia, hypophosphatemia, hypothyroidism, hemosiderosis, hemochromatosis, hypomagnesemia, iron storage disorders, diabetes, gout, neuropathic joint disease, trauma, surgery, oral parafunctional habits,
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Fig. 1. Patient with preauricular swelling.
Fig. 2. Panorex radiograph demonstrates flattened or nailhead condyle with sclerosis of articular eminence and cloudlike mass anterior to condylar head.
Fig. 3. Computed tomography. A, Coronal scan demonstrates the mass encircling the head of the condyle. B, Axial scan demonstrates a mass superior to flattened condyle with erosion and sclerosis of the temporal bone.
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Fig. 4. Histologic sections. A, Transmitted light shows aggerations of crystals embedded in collagen fibrous tissue with diffuse infiltrate of neutrophils and lymphocytes as well as chondrometaplasia. B, Polarized light of same section shows nodules of crystals that are positively birefringent. (Hematoxylin-eosin stain; original magnification X 100.) chronic renal dialysis, and chronic arthritic conditions. A familial component has also been described), 16 CPPD crystals m a y be found in articular as well as periarticular structures such as cartilage, capsule, synovial membrane, tendons, ligaments, and blood vessels. 5 However, CPPD crystals appear to have a definite predilection for fibrocartilage. 1 The pathogenesis of CPPD crystal deposition disease is not clearly understood. Both plasma and urine levels of inorganic pyrophosphate (PPi) seem normal. 18 The synovial fluid levels of PPi are thought to be elevated in these patients although serum and urine levels are within normal limits. This concentration gradient between synovial fluid and plasma implies a local origin of PPi. 5, 16 Some investigators propose that chondrocytes are overproducers of PPi because the crystals are first observed at the lacunar margin of these cells. 15 PPi has also been identified as a product of mammalian hyaline and fibrocartilage under tissue
culture conditions. 16 Enzymatic and metabolic defects have been detected and may account for the increased local levels of PPi favoring crystal formation, However, the exact mechanism of CPPD crystal synthesis and deposition has not been fully explained.
Case Report A 58-year-old man in otherwise excellent health was referred to the Toronto Hospital for the diagnosis and treatment of a painless swelling in the left preauricular region of approximately 18 months duration. The swelling had appeared suddenly and had remained the same size until 1 month before his referral when the swelling abruptly increased in size and then slowly decreased to its original size after 2 weeks of oral acetylsalicylic acid (aspirin) therapy. There was no history of joint pain or closed and open joint locking. Loading of the joint during eating and talking did not produce any joint symptoms, however, the patient noted that his "bite" did not feel right. The medical history was unremarkable, and specifically there was no history of disease involving any other joints.
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Fig. 5. Scanning electron photomicrograph of CPPD crystals. (Original magnification x1500.)
Physical examination showed a firm, nontender 3.0 X 3.0 cm swelling anterior to the left ear (Fig. 1). There was moderately limited translation of the left condyle and a slight deviation of the mandible to the left during mouth opening. The patient had an active mouth opening of 40 mm interincisally, and a mild crepitus was heard during auscultation of the left TMJ. The patient had a mild malocclusion characterized by a slight left posterior open bite with a mild anterior shift of the left mandible. Radiographic examination showed a cloudy, diffuse radiopacity anterior to the left condyle. The Condylar head was covered with a well-defined layer of cortical bone, but the articular surface was irregular and flattened showing the characteristic "nailhead" shape described by Good and Upton 6 (Fig. 2). A computed tomography scan indicated that the lesion originated within the left intra-articular space and showed a poorly defined peripheral soft tissue component completely encircling the head of the condyle. The superior joint space was irregular, showing erosion and sclerosis of the temporal component. The mass had displaced the condylar head anteriorly and inferiorly (Fig. 3). There was no involvement of the parotid gland. On the basis of the clinical findings and imaging studies, the differential diagnosis included synovial osteochondromatosis and CPPD arthropathy. In October 1993, the patient's left TMJ was explored with a preauricular approach. The joint capsule was mark-
edly distended, and a thick synovial fluid was apparent as the superior joint space was entered. A white, gritty, dough-like mass measuring 3.0 • 2.0 cm was removed from the anteromedial aspect of the upper joint space. Smaller portions of the lesion were also thoroughly curretted from the lateral and posterior aspects of this space. The inferior joint space was carefully examined, and no additional masses were found. The condylar head was covered with normal-looking fibrocartilage. The articular surface was rippled and smooth but markedly flattened. There was no evidence of erosive disease or osteophyte formation. The meniscus appeared normal in color and texture; It was markedly flattened when viewed from above, and it appeared somewhat biplanar in shape. There was no evidence of perforation. The disk was normally situated in relation to the condyle, however, it was somewhat anterior in its relationship to the temporal bone. Histologic examination of the sections by polarized light microscopy positively demonstrated birefringent parallel lipid crystals measuring 5 to l0 gm in length by 1.0 • 1.0 gm (Fig. 4, A). These crystals inhabited an amorphous matrix and the cells adjacent to the crystals showed chondrometaplasia and chronic synovitis with focal degenerative changes (Fig. 4, B). Scanning electron microscopic analysis demonstrated rhomboid and rod-like crystals ranging in size from 1 to 5 gm (Fig. 5). Infrared spectrophotometric analysis indicated that the crystals were CPPD. The
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Table I. Reported cases of CPPD deposition disease
Author
Side
Age
Sex
Signs/Symptoms
Pritzker et al. 19763
Right
55
M
Painless, swelling
de Vos et al. 198111
Left
51
F
Good and Upton 19826
Left
56
M
Zempelenyi and Calcaterra 19852 Kamatani et al. 19878
Left
51
F
Left
57
M
Chronic pain, deviation of mandible Painful swelling, pain on opening Painful swelling, trismus Abnormal occlusion
Gross et al. 19879 Mogi et al. 198712
Left Right
59 54
F F
Hutton et al. 19871~
Right
78
F
Right
76
F
Lambert et al. 19907
Right Right
68 41
F M
Acute pain, trismus Chronic painless mass, trismus and deafness
Magno et al. 19924
Left
53
F
Dijkgraff et al. 19925
Left
53
F
Pynn et al. 1994
Left
58
M
Painful joint, trismus Chronic pain, trismus and swelling Painful joint--acute trismus Acute ear pain, trismus
Medical History
Otherjoints
Urine/serum
Diabetes
No
Normal
Yes
Normal
Bruxism
Yes
Normal
--
No
Normal
Diabetes
No
Normal
Y e s
Normal Normal
m
No
m
Yes
m
Yes
----
Yes No
-Normal
Ear pain with deafness
No
Normal
Painful swelling--acute, deviation of mandible Painless swelling, malocclusion
Yes
Normal
No
Normal
patient's postoperative course was uneventful. His occlusion reverted to the premorbid state very shortly after surgery. At the 5-month follow-up examination, there were no signs or symptoms of TMJ disease. DISCUSSION Pain is the most common symptom associated with CPPD arthropathy of the TMJ, followed by swelling, malocclusion, trismus, and related ear problems. Pain is also the most prevalent feature of T M J internal derangement, a condition in which the cause may be closely related to CPPD crystal deposition disease. 5 According to Dijkgraff et al., 5 in CPPD crystal deposition disease of the TMJ, cartilage compliance and surface smoothness may be reduced, decreasing the gliding properties of the joint and resulting in eventual disk displacement. In osteoarthritis of the T M J in which the cartilage is initially affected, the same concept is thought to result in disk displacement. In this case, the accumulating mass of CPPD crystals had presumably flattened or moulded the disk and the underlying condylar articular surface. The disk was normally apposed to the underlying condyle but was displaced slightly anterior relative to the temporal
bone. Apparently, the pressure exerted by the expanding lesion had displaced the disk-condyle complex in an anterior and inferior direction but not enough to produce overt symptoms of internal derangement. Destructive arthropathy with CPPD deposits is a well-recognized entity and has been associated radiographically with cysts, bone fragmentation, osseous debris, osteophytes, and sclerosis. 3, 5, 7-10 In this patient, the CPPD arthropathy was confined to the superior joint space and had unexpectedly spared the lower joint space and the condyle. The temporal component, however, showed the classic radiographic signs of erosions and sclerosis so often attributed to the destructive arthropathy associated with this disease. In addition to lytic changes in the condyle and temporal bone, CPPD arthropathy can produce erosions in the zygomatic process and pterygoid plates. The radiographic appearance of CPPD deposition disease can be quite variable. More than half of the reported cases showed a calcified mass anterior to or attached to the condylar head and often encircling it. Not all cases associated with a mass showed destruc-
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Radiographic findings
Treatment
Recurrence
Moth-eaten appearance, destructive changes, articular erosion, calcified mass in coronoid notch Calcified mass on leading edge of condyle
Surgery
No
Surgery
No symptoms but radiographic changes
Flattened condyle, increased sclerosis of articular surfaces and reduction of space Dense mass between condyle and coronoid process, no destructive or lyric changes Dense mass between condyle and coronoid process, hypertrophic condyle Misshapen condylar head with destructive changes Irregular changes to fossa, two calcified masses
Medication
No
Surgery
No
Surgery
No
Surgery Surgery
No No
No abnormality
None
No
Calcified mass in joint space, loss of normal condylar shape Nonspecific changes Calcified mass in fossa surrounding condylar head, erosion and sclerosis of zygomatic process, temporal and pterygoid plates Irregular changes to condyle, erosion into temporal bone Calcified material in joint, irregular cortical changes
Medication
No
Medication Surgery
No No
Surgery
No
Surgery
Twice
Surgery
No
Calcified material in joint, flattened condyle, increased sclerosis of articular surfaces and reduction of space
tive or lytic changes in the condyle or temporal bone. Indeed, two cases of CPPD crystal deposition disease showed a well-defined mass with a radiographically normal joint. 2, 12 In this case, computed tomography scans of the left TMJ showed a calcified, cloudlike mass in the joint space that simulated synovial osteochondromatosis. CPPD crystal deposition disease has the ability to mimic other diseases. 5, 6 Not only can the clinical and radiographic features of CPPD crystal deposition disease be mistaken for other ailments, but the histologic characteristics of this disease may also emulate other disorders such as synovial osteochondromatosis. Currently, there is no definitive treatment for CPPD crystal deposition disease as its pathogenesis is not fully understood. 12 There are no means presently available to prevent progressive deposition of CPPD crystals within joints and other tissues. 2 Acute attacks may respond to aspirin, steroids, and other antiinflammatory medications. Colchicine also appears to be helpful in alleviating acute arthritic attacks and for prophylaxis. 4 Increased joint pressure may be reduced by aspiration of joint fluid.4 If masses of calcified material are deposited in the joint space and fibrocarti-
laginous meniscus, surgical excision is an effective way to remove these crystalline deposits, particularly for uniarticular involvement.4, 12 Although pain and swelling are the most common characteristics of CPPD arthropathy of the TMJ, indolent swellings in the region of the TMJ, especially in elderly patients, may be highly suggestive of this disorder. The diagnosis of CPPD crystal deposition disease should therefore be given serious consideration when these features are manifest. W e would like to thank Dr. K. Burgess and B. Chernecky for their assistance in producing the photomicrographs, and scanning electron micrograph. REFERENCES
1. Dieppe P, Calvert P. Crystals and joint disease. London: Chapman and Hall, 1983:154-88. 2. Zempelenyi J, Calcaterra TC. Chondrocalcinosis of the temporomandibular joint. Arch Otolaryngol Head Neck Surg 1985;111:403-5. 3. Pritzker KPH, Phillips H, Luk SC, et al. Pseudotumor of the temporomandibular joint: destructive calcium pyrophospate arthropathy. J Rheumatol 1976;3:770-81. 4. Magno WB, Lee SH, Schmidt J. Chondrocalcinosis of the temporomandibular joint: an external ear canal pseudotumor. ORAL SURG ORAL MED ORAL PATHOL 1992;73:262-5.
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March 1995 5. Dijkgraff LC, De Bont LGM, Leim RSB. Calcium pyrophosphate dihydrate deposition disease of the temporomandibular joint: report of a case. J Oral Maxillofac Surg 1992;50: 1003-9. 6. Good AE, Upton LG. Acute temporomandibular arthritis in a patient with bruxism and calcium pyrophosphate deposition disease. Arthritis Rheum 1982;25:353-5. 7. Lambert RGW, Becker E J, Pritzker KPH. Tumor of Calcium pyrophosphate dihydrate crystal arthopathy affecting the temporomandibular joint. Skeletal Radiol 1990;19:139-41. 8. Kamatani Y, Tagawa T, Hiranao Y, et al. Destructive calcium pyrophosphate dihydrate temporomandibular arthopathy. Int J Oral Maxillofac Surg 1987;16:749-52. 9. Gross BD, Williams RB, DiPosimo C J, Williams SV. Gout and pseudogout of the temporomandibular joint. ORALSURGORAL MED ORAL PATHOL 1987;63:551-4. 10. Hutton CW, Dohertz M, Dieppe PA. Acute pseudogout of the temporomandibular joint: report of three cases and review of the literature. Br J Rheumatol 1987;26:51-2. 11. de Vos RAI, Brans J, Jusen G J, Becker AE. Calcium pyrophosphate dihydrate arthopathy of the temporomandibufar joint. ORAL SURG ORAL MED ORAL PATHOL 1981; 51:1497-502. 12. Mogi G, Kuga M, Kawauchi H. Chondorcalcinosis of the temporomandibular joint: calcium pyrophosphate dihydrate deposition disease. Arch Otolaryngol Head Neck Surg 1987; 113:1117-9. 13. Zitnan D, Sitaj S. Mnohopcentna familiarha kalcifikaaz artikularnych chrupiek. Bratisl Lek Listy 1958;38:217-28.
14. Kohn NN, Hughes RE, McCarty D J, et al. The significance of calcium phosphate crystals in the synovial fluid of arthritic patients: the "pseudogout syndrome." II. Ann Intern Med 1962;56:738-45. 15. McCarty D J, Kohn NN, Faires JS. The significance of calcium phosphate crystals in the synovial fluid of arthritic patients: the "pseudogout syndrome." I. Ann Intern Med 1962;56:711-37. 16. Ryan ML, McCarty DJ. Calcium pyrophosphate dihydrate deposition disease: pseudogout and articular chondorcalcinosis. In: McCarty D J, ed. Arthritis and allied conditions. 10th ed. Philadelphia: Lea and Febiger, 1985:1515-46. 17. Resnick D, Niwayama G, Goergen TG, et al. Clinical, radiolographic, and pathologic abnormality in calcium pyrophosphate dihydrate deposition disease (CPPD): pseudogout. Radiology 1977;22:1-15. 18. Altman RD, Muniz O, Pita H, et al. Articular chondorcalcinosis: microanalysis of pyrophosphate (PPi) in synovial fluid and plasma. Arthritis Rheum 1973;16:1971-8.
Reprint requests: Simon Weinberg, DDS, FRCD(C) Faculty of Dentistry University of Toronto 124 Edward Street Toronto, Ontario Canada M5G 1G6
An asymptomatic preauricular swelling in a 58-year-old man appeared as a parotid mass and was diagnosed as calcium pyrophosphate dihydrate crystal deposition disease of the temporomandibular joint. This article describes the diagnostic criteria and management of this rare condition and reviews the 13 cases that have been reported to date. (O~ALSURGO~At MED ORALPATHOLORALRADIOLENDOD1995;79:278414)
The deposition of calcium pyrophosphate dihydrate (CPPD) crystals seems to have a definite predilection for fibrocartilage rather than hyaline cartilage. 1 Therefore it is surprising that the temporomandibular joint (TMJ), a joint in which fibrocartilage rather than hyaline cartilage predominates, is so rarely affected by CPPD deposition disease. The occurrence of CPPD arthropathy of the TMJ is uncommon, and to our knowledge only thirteen cases of this condition have been reported. This article adds, an additional case report to the literature and tabulates the pertinent, clinical, and radiographic features of all reported cases, lq2 Zitnan and Sitaj first described CPPD arthropathy as a specific disease entity in 1958.13 They applied the term chondrocalcinosis to the characteristic radiographic appearance of linear punctate calcifications within the fibrocartilaginous meniscus of the knee joint. Because of the high concentration of CPPD crystals rather than urate crystals within the synovial fluid of patients with gout-like symptoms, Kohn et al. 14 suggested the term pseudogout to describe this condition. The significance of phosphate crystals in the synovial fluid of arthritic patients was described by McCarty et al. 15 in 1962. As CPPD crystals deposition may present a large spectrum of clinical manifestations, Ryan and McCarty 16 proposed the name calcium pyrophosphate dihydrate (CPPD) deposition disease as a more general term. aSenior Resident, Division of Oral and Maxillofacial Surgery, The Toronto Hospital and Faculty of Dentistry, University of Toronto. bprofessor, Division of Oral and Maxillofacial Surgery, The Toronto Hospital and Faculty of Dentistry, University of Toronto. CAssistant Professor, Department of Otolaryngology/Head and Neck Program, The Toronto Hospital and Faculty of Medicine,
Universityof Toronto. Copyright9 1995 by Mosby-YearBook, Inc. 1079-2104/95/$3.00 + 0 7/12/60302 278
The salient clinical and radiographic features of the reported cases of CPPD crystal deposition disease involving the T M J have been tabulated (Table I). Crystal deposition in CPPD favors fibrocartilage, and the knee has been involved in more than 50% of the reported studies that document chondrocalcinosis.2 One would therefore anticipate that the TMJ would be a regular site of crystal deposition because its articular surfaces and articular disk are comprised entirely of fibrocartilage. Pritzker et al. 3 were the first to describe CPPD crystal deposition disease in the TMJ. They postulated that the paucity of reports in the literature may be due to the lack of clinical distinction between the arthritides and other causes of T M J pain, infrequent investigations into the nature of the pathologic joint, and the peculiar anatomy of the TMJ. Although there is currently no satisfactory explanation, the TMJ remains an unusual location of crystal-induced synovitis. The following diagnostic criteria have been established by Resnick et a1.17 for CPPD crystal deposition disease: CPPD crystals are detected in the fibrocartilage of a joint by electron microscopy or x-ray diffraction; crystals compatible with CPPD are found with the use of polarized light; and the patient has a diagnostic radiographic pattern. If only one of these criteria is present, a diagnosis of probable but not definitive chondrocalcinosis is made. CPPD deposition disease occurs more often in women with an increasing incidence beyond the fifth decade of life. l, 4 Various predisposing factors have been associated with CPPD crystal deposition disease, and these include hyperparathyroidism, hypercalcemia, hypophosphatemia, hypothyroidism, hemosiderosis, hemochromatosis, hypomagnesemia, iron storage disorders, diabetes, gout, neuropathic joint disease, trauma, surgery, oral parafunctional habits,
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Fig. 1. Patient with preauricular swelling.
Fig. 2. Panorex radiograph demonstrates flattened or nailhead condyle with sclerosis of articular eminence and cloudlike mass anterior to condylar head.
Fig. 3. Computed tomography. A, Coronal scan demonstrates the mass encircling the head of the condyle. B, Axial scan demonstrates a mass superior to flattened condyle with erosion and sclerosis of the temporal bone.
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Fig. 4. Histologic sections. A, Transmitted light shows aggerations of crystals embedded in collagen fibrous tissue with diffuse infiltrate of neutrophils and lymphocytes as well as chondrometaplasia. B, Polarized light of same section shows nodules of crystals that are positively birefringent. (Hematoxylin-eosin stain; original magnification X 100.) chronic renal dialysis, and chronic arthritic conditions. A familial component has also been described), 16 CPPD crystals m a y be found in articular as well as periarticular structures such as cartilage, capsule, synovial membrane, tendons, ligaments, and blood vessels. 5 However, CPPD crystals appear to have a definite predilection for fibrocartilage. 1 The pathogenesis of CPPD crystal deposition disease is not clearly understood. Both plasma and urine levels of inorganic pyrophosphate (PPi) seem normal. 18 The synovial fluid levels of PPi are thought to be elevated in these patients although serum and urine levels are within normal limits. This concentration gradient between synovial fluid and plasma implies a local origin of PPi. 5, 16 Some investigators propose that chondrocytes are overproducers of PPi because the crystals are first observed at the lacunar margin of these cells. 15 PPi has also been identified as a product of mammalian hyaline and fibrocartilage under tissue
culture conditions. 16 Enzymatic and metabolic defects have been detected and may account for the increased local levels of PPi favoring crystal formation, However, the exact mechanism of CPPD crystal synthesis and deposition has not been fully explained.
Case Report A 58-year-old man in otherwise excellent health was referred to the Toronto Hospital for the diagnosis and treatment of a painless swelling in the left preauricular region of approximately 18 months duration. The swelling had appeared suddenly and had remained the same size until 1 month before his referral when the swelling abruptly increased in size and then slowly decreased to its original size after 2 weeks of oral acetylsalicylic acid (aspirin) therapy. There was no history of joint pain or closed and open joint locking. Loading of the joint during eating and talking did not produce any joint symptoms, however, the patient noted that his "bite" did not feel right. The medical history was unremarkable, and specifically there was no history of disease involving any other joints.
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Fig. 5. Scanning electron photomicrograph of CPPD crystals. (Original magnification x1500.)
Physical examination showed a firm, nontender 3.0 X 3.0 cm swelling anterior to the left ear (Fig. 1). There was moderately limited translation of the left condyle and a slight deviation of the mandible to the left during mouth opening. The patient had an active mouth opening of 40 mm interincisally, and a mild crepitus was heard during auscultation of the left TMJ. The patient had a mild malocclusion characterized by a slight left posterior open bite with a mild anterior shift of the left mandible. Radiographic examination showed a cloudy, diffuse radiopacity anterior to the left condyle. The Condylar head was covered with a well-defined layer of cortical bone, but the articular surface was irregular and flattened showing the characteristic "nailhead" shape described by Good and Upton 6 (Fig. 2). A computed tomography scan indicated that the lesion originated within the left intra-articular space and showed a poorly defined peripheral soft tissue component completely encircling the head of the condyle. The superior joint space was irregular, showing erosion and sclerosis of the temporal component. The mass had displaced the condylar head anteriorly and inferiorly (Fig. 3). There was no involvement of the parotid gland. On the basis of the clinical findings and imaging studies, the differential diagnosis included synovial osteochondromatosis and CPPD arthropathy. In October 1993, the patient's left TMJ was explored with a preauricular approach. The joint capsule was mark-
edly distended, and a thick synovial fluid was apparent as the superior joint space was entered. A white, gritty, dough-like mass measuring 3.0 • 2.0 cm was removed from the anteromedial aspect of the upper joint space. Smaller portions of the lesion were also thoroughly curretted from the lateral and posterior aspects of this space. The inferior joint space was carefully examined, and no additional masses were found. The condylar head was covered with normal-looking fibrocartilage. The articular surface was rippled and smooth but markedly flattened. There was no evidence of erosive disease or osteophyte formation. The meniscus appeared normal in color and texture; It was markedly flattened when viewed from above, and it appeared somewhat biplanar in shape. There was no evidence of perforation. The disk was normally situated in relation to the condyle, however, it was somewhat anterior in its relationship to the temporal bone. Histologic examination of the sections by polarized light microscopy positively demonstrated birefringent parallel lipid crystals measuring 5 to l0 gm in length by 1.0 • 1.0 gm (Fig. 4, A). These crystals inhabited an amorphous matrix and the cells adjacent to the crystals showed chondrometaplasia and chronic synovitis with focal degenerative changes (Fig. 4, B). Scanning electron microscopic analysis demonstrated rhomboid and rod-like crystals ranging in size from 1 to 5 gm (Fig. 5). Infrared spectrophotometric analysis indicated that the crystals were CPPD. The
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Table I. Reported cases of CPPD deposition disease
Author
Side
Age
Sex
Signs/Symptoms
Pritzker et al. 19763
Right
55
M
Painless, swelling
de Vos et al. 198111
Left
51
F
Good and Upton 19826
Left
56
M
Zempelenyi and Calcaterra 19852 Kamatani et al. 19878
Left
51
F
Left
57
M
Chronic pain, deviation of mandible Painful swelling, pain on opening Painful swelling, trismus Abnormal occlusion
Gross et al. 19879 Mogi et al. 198712
Left Right
59 54
F F
Hutton et al. 19871~
Right
78
F
Right
76
F
Lambert et al. 19907
Right Right
68 41
F M
Acute pain, trismus Chronic painless mass, trismus and deafness
Magno et al. 19924
Left
53
F
Dijkgraff et al. 19925
Left
53
F
Pynn et al. 1994
Left
58
M
Painful joint, trismus Chronic pain, trismus and swelling Painful joint--acute trismus Acute ear pain, trismus
Medical History
Otherjoints
Urine/serum
Diabetes
No
Normal
Yes
Normal
Bruxism
Yes
Normal
--
No
Normal
Diabetes
No
Normal
Y e s
Normal Normal
m
No
m
Yes
m
Yes
----
Yes No
-Normal
Ear pain with deafness
No
Normal
Painful swelling--acute, deviation of mandible Painless swelling, malocclusion
Yes
Normal
No
Normal
patient's postoperative course was uneventful. His occlusion reverted to the premorbid state very shortly after surgery. At the 5-month follow-up examination, there were no signs or symptoms of TMJ disease. DISCUSSION Pain is the most common symptom associated with CPPD arthropathy of the TMJ, followed by swelling, malocclusion, trismus, and related ear problems. Pain is also the most prevalent feature of T M J internal derangement, a condition in which the cause may be closely related to CPPD crystal deposition disease. 5 According to Dijkgraff et al., 5 in CPPD crystal deposition disease of the TMJ, cartilage compliance and surface smoothness may be reduced, decreasing the gliding properties of the joint and resulting in eventual disk displacement. In osteoarthritis of the T M J in which the cartilage is initially affected, the same concept is thought to result in disk displacement. In this case, the accumulating mass of CPPD crystals had presumably flattened or moulded the disk and the underlying condylar articular surface. The disk was normally apposed to the underlying condyle but was displaced slightly anterior relative to the temporal
bone. Apparently, the pressure exerted by the expanding lesion had displaced the disk-condyle complex in an anterior and inferior direction but not enough to produce overt symptoms of internal derangement. Destructive arthropathy with CPPD deposits is a well-recognized entity and has been associated radiographically with cysts, bone fragmentation, osseous debris, osteophytes, and sclerosis. 3, 5, 7-10 In this patient, the CPPD arthropathy was confined to the superior joint space and had unexpectedly spared the lower joint space and the condyle. The temporal component, however, showed the classic radiographic signs of erosions and sclerosis so often attributed to the destructive arthropathy associated with this disease. In addition to lytic changes in the condyle and temporal bone, CPPD arthropathy can produce erosions in the zygomatic process and pterygoid plates. The radiographic appearance of CPPD deposition disease can be quite variable. More than half of the reported cases showed a calcified mass anterior to or attached to the condylar head and often encircling it. Not all cases associated with a mass showed destruc-
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Radiographic findings
Treatment
Recurrence
Moth-eaten appearance, destructive changes, articular erosion, calcified mass in coronoid notch Calcified mass on leading edge of condyle
Surgery
No
Surgery
No symptoms but radiographic changes
Flattened condyle, increased sclerosis of articular surfaces and reduction of space Dense mass between condyle and coronoid process, no destructive or lyric changes Dense mass between condyle and coronoid process, hypertrophic condyle Misshapen condylar head with destructive changes Irregular changes to fossa, two calcified masses
Medication
No
Surgery
No
Surgery
No
Surgery Surgery
No No
No abnormality
None
No
Calcified mass in joint space, loss of normal condylar shape Nonspecific changes Calcified mass in fossa surrounding condylar head, erosion and sclerosis of zygomatic process, temporal and pterygoid plates Irregular changes to condyle, erosion into temporal bone Calcified material in joint, irregular cortical changes
Medication
No
Medication Surgery
No No
Surgery
No
Surgery
Twice
Surgery
No
Calcified material in joint, flattened condyle, increased sclerosis of articular surfaces and reduction of space
tive or lytic changes in the condyle or temporal bone. Indeed, two cases of CPPD crystal deposition disease showed a well-defined mass with a radiographically normal joint. 2, 12 In this case, computed tomography scans of the left TMJ showed a calcified, cloudlike mass in the joint space that simulated synovial osteochondromatosis. CPPD crystal deposition disease has the ability to mimic other diseases. 5, 6 Not only can the clinical and radiographic features of CPPD crystal deposition disease be mistaken for other ailments, but the histologic characteristics of this disease may also emulate other disorders such as synovial osteochondromatosis. Currently, there is no definitive treatment for CPPD crystal deposition disease as its pathogenesis is not fully understood. 12 There are no means presently available to prevent progressive deposition of CPPD crystals within joints and other tissues. 2 Acute attacks may respond to aspirin, steroids, and other antiinflammatory medications. Colchicine also appears to be helpful in alleviating acute arthritic attacks and for prophylaxis. 4 Increased joint pressure may be reduced by aspiration of joint fluid.4 If masses of calcified material are deposited in the joint space and fibrocarti-
laginous meniscus, surgical excision is an effective way to remove these crystalline deposits, particularly for uniarticular involvement.4, 12 Although pain and swelling are the most common characteristics of CPPD arthropathy of the TMJ, indolent swellings in the region of the TMJ, especially in elderly patients, may be highly suggestive of this disorder. The diagnosis of CPPD crystal deposition disease should therefore be given serious consideration when these features are manifest. W e would like to thank Dr. K. Burgess and B. Chernecky for their assistance in producing the photomicrographs, and scanning electron micrograph. REFERENCES
1. Dieppe P, Calvert P. Crystals and joint disease. London: Chapman and Hall, 1983:154-88. 2. Zempelenyi J, Calcaterra TC. Chondrocalcinosis of the temporomandibular joint. Arch Otolaryngol Head Neck Surg 1985;111:403-5. 3. Pritzker KPH, Phillips H, Luk SC, et al. Pseudotumor of the temporomandibular joint: destructive calcium pyrophospate arthropathy. J Rheumatol 1976;3:770-81. 4. Magno WB, Lee SH, Schmidt J. Chondrocalcinosis of the temporomandibular joint: an external ear canal pseudotumor. ORAL SURG ORAL MED ORAL PATHOL 1992;73:262-5.
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March 1995 5. Dijkgraff LC, De Bont LGM, Leim RSB. Calcium pyrophosphate dihydrate deposition disease of the temporomandibular joint: report of a case. J Oral Maxillofac Surg 1992;50: 1003-9. 6. Good AE, Upton LG. Acute temporomandibular arthritis in a patient with bruxism and calcium pyrophosphate deposition disease. Arthritis Rheum 1982;25:353-5. 7. Lambert RGW, Becker E J, Pritzker KPH. Tumor of Calcium pyrophosphate dihydrate crystal arthopathy affecting the temporomandibular joint. Skeletal Radiol 1990;19:139-41. 8. Kamatani Y, Tagawa T, Hiranao Y, et al. Destructive calcium pyrophosphate dihydrate temporomandibular arthopathy. Int J Oral Maxillofac Surg 1987;16:749-52. 9. Gross BD, Williams RB, DiPosimo C J, Williams SV. Gout and pseudogout of the temporomandibular joint. ORALSURGORAL MED ORAL PATHOL 1987;63:551-4. 10. Hutton CW, Dohertz M, Dieppe PA. Acute pseudogout of the temporomandibular joint: report of three cases and review of the literature. Br J Rheumatol 1987;26:51-2. 11. de Vos RAI, Brans J, Jusen G J, Becker AE. Calcium pyrophosphate dihydrate arthopathy of the temporomandibufar joint. ORAL SURG ORAL MED ORAL PATHOL 1981; 51:1497-502. 12. Mogi G, Kuga M, Kawauchi H. Chondorcalcinosis of the temporomandibular joint: calcium pyrophosphate dihydrate deposition disease. Arch Otolaryngol Head Neck Surg 1987; 113:1117-9. 13. Zitnan D, Sitaj S. Mnohopcentna familiarha kalcifikaaz artikularnych chrupiek. Bratisl Lek Listy 1958;38:217-28.
14. Kohn NN, Hughes RE, McCarty D J, et al. The significance of calcium phosphate crystals in the synovial fluid of arthritic patients: the "pseudogout syndrome." II. Ann Intern Med 1962;56:738-45. 15. McCarty D J, Kohn NN, Faires JS. The significance of calcium phosphate crystals in the synovial fluid of arthritic patients: the "pseudogout syndrome." I. Ann Intern Med 1962;56:711-37. 16. Ryan ML, McCarty DJ. Calcium pyrophosphate dihydrate deposition disease: pseudogout and articular chondorcalcinosis. In: McCarty D J, ed. Arthritis and allied conditions. 10th ed. Philadelphia: Lea and Febiger, 1985:1515-46. 17. Resnick D, Niwayama G, Goergen TG, et al. Clinical, radiolographic, and pathologic abnormality in calcium pyrophosphate dihydrate deposition disease (CPPD): pseudogout. Radiology 1977;22:1-15. 18. Altman RD, Muniz O, Pita H, et al. Articular chondorcalcinosis: microanalysis of pyrophosphate (PPi) in synovial fluid and plasma. Arthritis Rheum 1973;16:1971-8.
Reprint requests: Simon Weinberg, DDS, FRCD(C) Faculty of Dentistry University of Toronto 124 Edward Street Toronto, Ontario Canada M5G 1G6