Journal
of Dentistry,
4, 123-l
28
Psoriatic arthritis and the temporomandibular joint G. Stewart Blair,
MIX,
FDS, HDD
Department of Oral Surgery, The Dental School, University of Newcastle upon Tyne ABSTRACT The clinical and radiological changes produced by psoriatic arthritis in the temporomandibular joints of 7 patients are described. There are few references in the literature to such changes, owing, perhaps, to the comparative rarity of this condition and to the difficulty of examining these joints radiologically. The possibility of the progression of Reiter’s disease to psoriatic arthritis is mentioned. The changes described are in many ways similar to those produced by rheumatoid arthritis. It is important that patients who display such abnormalities but are known not to be suffering from rheumatoid arthritis should be properly investigated for psoriatic arthritis.
INTRODUCTION PSORIATICarthritis
is defined on the triad of (a) psoriasis, (b) radiological erosive polyarthritis and (c) a negative serological test for rheumatoid factor (Boyle and Buchanan, 1971). It is, therefore, an entity quite distinct from rheumatoid arthritis. This distinction is further marked by the simultaneous occurrence of both joint and skin manifestations in many instances, by characteristic radiological appearances, by the absence of subcutaneous nodules and by the fact that psoriatic arthritis affects males more frequently than females. It has, however, been suggested that the structural changes produced in both conditions may be very similar (Wright, 1961; Lundberg and Ericson, 1967). The first report that psoriatic arthritis could affect any of the oral structures was published only 11 years ago (Lundberg, 1965). In the
same year Franks (1965) reported another case. The largest study to date (Lundberg and Ericson, 1967) which consisted of I1 cases, was also related to the temporomandibular joints. The temporomandibular joints of 7 patients suffering from psoriatic arthritis were examclinically and radioined, coincidentally, logically during the course of a study of adult rheumatoid arthritis previously reported by Chalmers and Blair (1973). Although the number involved is small it is felt to be important to detail the results of these examinations. This conclusion has been reached not only in view of the paucity of information on the subject in the literature but also because further evidence is provided to bear out the contention that the changes discovered in the psoriatic arthritic temporomandibular joint may be mistaken for those of rheumatoid arthritis.
PATIENTS
AND
METHODS
Seven patients with psoriatic arthritis were examined. Their disease was of sufficient severity to warrant outpatient attendance at a specialist centre. Otherwise the patients were unselected. There were 4 females and 3 males whose ages varied from 43 to 67 years (mean 53.8 years). The duration of the disease ranged from 6 months to 21 years (mean 4.8 years) and the ages of the patients at the time of onset of the disease from 28 to 66 years (mean 49.2 years). All had negative serological tests for rheumatoid factor and satisfied the definition of psoriatic arthritis.
124
Journal of Dentistry, Vol. ~/NO. 3
Clinical examination of the temporomandibular joint
This was completed at the same time as the temporomandibular joint examination. Its purpose was to ascertain whether or not dental abnormalities might be responsible for any of the temporomandibular joint abnormalities discovered.
‘rheumatic’ condition. The positions of the mandibular condyle were considered first. With the teeth in occlusion, the position of the condylar head in the articular fossa was designated ‘normo-‘, ‘antero-‘, or ‘retro-‘. If the condylar head was not lying within the fossa ‘subluxation in the closed position’ was said to be present. An interarticular space of less than 0.5 mm was regarded as ‘reduced’ (Madsen, 1966). With the mouth maximally open, a reading of -4.0 mm or less was considered to indicate ‘reduced mobility’ and of +4*0 mm or more ‘increased mobility’, according to the criteria of Madsen (1966). ‘Increased mobility’ was not considered to be an abnormality unless there were associated clinical features, when it was described as ‘subluxation in the open position’. Fibrous or bony ankylosis was also sought. The condition of the calcified structures was then evaluated. The following were classed as abnormalities: sclerosis of one or other of the articular surfaces; surface and pocket erosions; flattening of the mandibular condyle or articular eminence; marginal proliferations of the condylar head; subchondral cysts and calcification of the articular disc. The presence of osteoporosis was recorded but was not regarded as an abnormal finding (Lundberg and Ericson, 1967).
Radiological examination of the temporomandibular joint
Comparison with rheumatoid arthritis
The 14 joints were radiographed in the normally occluded and maximally open positions using circular tomography. This examination was repeated or, alternatively, either orthopantomography or lateral transcranio-oblique radiography was used if there was any doubt in the interpretation of any radiograph.
Chalmers and Blair (1973) suggested that. clinically, limitation of opening, stiffness; crepitus, referred pains and tenderness on biting were significantly more common among patients with adult rheumatoid arthritis than among control patients, with tenderness on palpation and pain being present more frequently but not quite significantly so. In addition, Anderson and Blair (1975) have recently described a method of scoring the features seen on temporomandibular joint radiographs in an attempt to distinguish a rheumatoid arthritic from a normal population. The 7 psoriatic arthritic patients were similarly screened to determine further any similarities in the changes produced in the temporomandibular joints of patients suffering
This examination was performed as described by Chalmers and Blair (1973). The presence or absence of the following abnormal features was recorded: deviation of the mandible from the midline during opening and closing movements; limitation of opening; subjective stiffness of the joint; joint crepitus on palpation; audible or palpable clicking of the joint detected objectively; subjective joint clicking; pain in the joint itself, referred pain or tenderness of the joint on biting or chewing; tenderness of the joint, joint capsule or muscles of mastication detected by palpation while the patient was performing the full range of mandibular movements; past history of, or presence of, soft-tissue swelling external to the temporomandibular joint; subluxation. A history of any abnormality which was considered to be in any way doubtful was not accepted.
Clinical examination mouth
Radiological
of the
interpretation
All the radiographs were examined ‘blind’ and in random order by a single observer. This feature was facilitated by the fact that these radiographs were included, haphazardly, among a large number of radiographs of patients with rheumatoid arthritis and primary osteoarthrosis as well as other systemic conditions, and also of patients with no detectable
125
Blair: Psoriatic Arthritis and Temporomandibular Joint Tab/e /.-Summary
of clinical
and radiological
No. of patients
Clinical feature Deviation Limitation of opening Stiffness Audible click (subjective Palpable click Pain Referred pain Tenderness on biting Tenderness on palpation
and objective)
Total with abnormalities Total with either clinical or radiological One patient One patient One patient He had no overclosure
features recorded
5 abnormalities
No, of patients
No. of joints
Antero-position Retro-position Reduced mobility Subluxation (closed) Surface erosions Flattening Calcified disc Osteoporosis-total Osteoporosis alone
4 1 2 1 2 2 1 3 1
6 2 2 2 2 3 1 5 2
Total with abnormalities or both, 6 patients
5
7
Radiological feature
with several clinical abnormalities had no radiological abnormalities. with a number of radiological abnormalities had no clinical abnormalities. in addition complained of tenderness on palpation and pain of his right temporomandibular joint. other clinical or radiological abnormalities of either joint. These symptoms may have been due to and a poor occlusion and, accordingly, he was classified as ‘normal’.
from either arthritis.
rheumatoid
arthritis
or psoriatic
RESULTS The results of the examinations are summarized in Tables I and II. Table I details only the clinical and radiological features recorded. Features sought but not recorded are excluded. Clinical abnormalities were present in 6 patients, but one (patient 6) was excluded from the final total because his complaints were probably associated with his unsatisfactory dentures. Radiological abnormalities were seen on the radiographs of 5 patients (Figs. I, 2 and 3), 4 of whom also had clinical abnormalities. either clinical or radiological Therefore, abnormalities or both were recorded for 6 of the 7 patients. Table ZI compares the recorded features with those found significantly more frequently in a rheumatoid arthritic than a normal population. The patient with the lowest radiological score also displayed the greatest number of clinical abnormalities. However, the patient with the second lowest radiological score appeared to be normal clinically, and the patient with the next lowest displayed only one clinically abnormal feature. On the other hand, the patients with a score of +0*8 presented with
Table //.-Scoring of clinical and radiological abnormalities detected as possible features of rheumatoid arthritis
Patient
1 2 3 4 5 6 7
Clinical abnormality present * Yes No Yes Yes Yes No Yes
Radiological score t (normal or maximum + 1 .l ) +0.8 -2.7 --7.6 i-l.1 iO.8 t1.1 - 1.1
*Primarily, limitation of opening, stiffness, referred pain and tenderness on biting. Secondary tenderness on palpation and pain. $Score .S = 1~1-0~3a-1~2b-1~8c-3~5d-2~3e-1~9f-2~4g. where a represents antero-position, b reduced mobility, c subluxation in the closed position, d surface erosions, e pocket erosions, f flattening and g marginal proliferations (Anderson and Blair, 1975).
one primary and one secondary and two primary and one secondary clinical abnormalities respectively. Also, one patient with a normal radiological score was found to have one primary and one secondary abnormal clinical features. The seventh patient (patient 6) has already been mentioned.
126
Fig.
Journal of Dentistry, Vol. ~/NO. 3
I.-Antero-position
of the condylar head
Fig. 3.-Reduced mobility of the left condyle with the mouth held as widely open as possible. Surface erosions are also evident.
DISCUSSION The temporomandibular joints of 7 patients with psoriatic arthritis have been studied clinically and radiologically. These examinations were completed without prior knowledge of the underlying condition. This was readily achieved as the 7 patients were included in a total of 219 patients, each of whom was examined in exactly the same manner. The majority of these patients suffered from rheumatoid arthritis, and two other large groups comprised osteoarthritic and normal patients. All the examinations were completed by one person. The radiographic techniques used have been shown to be very suitable for examining the temporomandibular joint (Blair
Fig.
2.-The condyle is in retro-position and also demonstrates surface erosions.
and Chalmers, 1972; Blair et al., 1973). The prevalences of both clinical and radiological changes were found to be high. In addition, many of the changes discovered were similar to those which experience would lead one to suspect a diagnosis of rheumatoid arthritis. Only 7 patients were examined. This is, however, the second largest series reported. One reason for this may be the relative rarity of the condition. Psoriasis is found in only about 2 per cent of the adult population of northern Europe and North America (Baker, 1966). The incidence of polyarthritis in psoriatic population samples is an estimated 7 per cent in hospital series (Baker, 1975). Another reason is the lack of study, especially radiological, of arthritis and arthrosis of the temporomandibular joint. The very position of the joint in relationship to the skull has compounded this problem (Uotila, 1964). In addition, the present series would appear to be the first to detail the clinical and radiological findings and to compare and contrast these with changes which have been described in rheumatoid arthritic populations. It might be thought an example ofchance that 6 of the 7 patients examined showed temporomandibular joint changes. After all, only 39 of the 95 control patients in the investigation of Chalmers and Blair (1973) of patients with rheumatoid arthritis had temporomandibular joint changes. If their figures are analysed, however, it can be seen that at most 10 of the control patients exhibited what have been
Blair: Psoriatic Arthritis and Temporomandibular Joint
127
quite usual percentage for a normal population described as primary abnormalities, compared -were so affected in the present series. with 5 of the total of 7 psoriatic arthritic Such changes and differences are not patients. The clinical changes in these two unexpected. Wright (1959) described three groups, therefore, are different in character. patterns of psoriatic arthritis, the third of Exactly the same can be said for the radiowhich closely resembles rheumatoid arthritis logical changes. Only 2 of a total of 83 control clinically although tending to involve fewer patients studied by Anderson and Blair (1975) joints and to be less disabling. This would had a score less than ~ 1.0, and only 39.8 per largely accord with the findings in the present cent produced a score less than the maximum of -t 1.1. Three of the 7 patients in this stfi~dJ%XZl series. Wtight’s second pattern is deforming, may involve any joint and occurs in a younger scores of - -7.6, -2.7 and - 1.1 respectively, age group. Interestingly, the patient in the and 2 more had a score less than the maximum. present series who showed the largest number Thus, 71.4 per cent had scores of less than and greatest severity of abnormalities had -:-1.1. On the other hand, by the same reasoncontracted the disease at the earliest age and ing it can be understood that many of the had suffered from it over the longest period. changes produced by psoriatic arthritis must More of the patients reported by Lundberg and be similar to those produced by rheumatoid Ericson (1967) may have fallen into this arthritis. A further similarity between these pattern. Indeed, the age range of their patients two diseases is the reasonably good correwas17-64years(mean39.Oyears),comparedwith lation between the clinical and radiological 43-67 years (mean 53.8 years) in this series. findings (Table 111). One clinical abnormality Boyle and Buchanan (1971) discussed how which may be seen more commonly among Reiter’s disease may progress to a picture patients with psoriatic arthritis is deviation clinically indistinguishable from psoriatic arthof the mandible during opening and closing ritis after repeated attacks in a very small movements. number of patients. One 27-year-old man with Reiter’s disease was examined, and it is of Tab/e l//.--Relationship between clinical and interest to note that the clinical tempororadiological status mandibular joint abnormalities recorded inClinical Radiological No. % cluded stiffness, crepitus, pain, deviation and status status audible and palpable clicking as well as radioAbnormal Abnormal 4 57.1 logical reduced mobility of the left condyle. Abnormal Normal 1 14.3 These abnormalities, with the exception of Normal Abnormal 1 14.3 crepitus, were among those discovered most Normal Normal 1 14.3 frequently among the 7 psoriatic arthritic patients of the present series. Lundberg and Ericson (1967) also described In conclusion, it may be stated that involvemany radiological abnormalities affecting the ment of the temporomandibular joint by temporomandibular joints of 11 patients psoriatic arthritis would appear to be common suffering from psoriatic arthritis whom they and that this involvement may closely resemble studied. In fact, the incidence of radiological that of rheumatoid arthritis. If such changes changes was higher and their severity greater are discovered and the investigations for than was seen in the present series. Although rheumatoid arthritis prove to be negative it they do not provide a breakdown of their must not be concluded that the patient is free results, at least 9 of their 11 patients must have of an underlying systemic condition which had a radiological score of - 1.2 or less. They could be responsible for the temporomandialso stated that osteoporosis, in combination bular joint arthritis. Although similar in some with at least one other observable change, was respects, rheumatoid arthritis and psoriatic seen in 55.5 per cent of the joints in their study, arthritis are different entities requiring different
128
Acknowledgements I wish to thank Miss A. Carson for the cheerful and unfailing production of excellent radiographs, Professor W. Watson Buchanan for his advice and encouragement and Mrs M. Burton for invaluable secretarial assistance.
REFERENCES ANDERSONJ. A. and BLAIR G. S. (1975) Screening in a dental clinic for adult rheumatoid arthritis involving the temporomandibular joint using a statistical discriminant function. J. Oral Rehabil. 2, 187-197.
BAKER H. (1966) Epidemiological aspects of psoriasis and arthritis. Br. J. Dermatol. 78, 249261.
BAKER H. (1975) Psoriasis. Br. J. Hosp. Med. 13, 547-563.
BLAIRG. S. and CHALMERSI. M. (1972) Radiology of the temporomandibular joint. J. Dent. 1, 69-76.
BLAIR G. S., CHALMERSI. M., LEGGAT T. G. and BUCHANANW. W. (1973) Circular tomography of the temporomandibular joint. Oral Surg. 35, 416427.
Journal of Dentistry,
Vol. ~/NO. 3
BOYLEJ. A. and BUCHANANW. W. (1971) Clinical Rheumatology. Oxford, Blackwell, pp. 304-317. CHALMERSI. M. and BLAIR G. S. (1973) Rheumatoid arthritis of the temporomandibular joint. Q. J. Med. 42,369-386. FRANKSA. S. T. (1965) Temporomandibular joint arthrosis associated with psoriasis. Oral Surg. 19, 301-303. LUNDBERG M. (1%5) Rijntgendiagnostik vid kakledsbesvar. Odontol. F&en. Tidsskr. 29, 209240.
LUNDBERGM. and ERICSONS. (1967) Changes in the temporomandibular joint in psoriasis arthropathica. Acta Derm. Venereol. (Stockh.) 47, 354-358.
MADSENB. (1966) Normal variations in anatomy, condylar movements and arthrosis frequency of the temporomandibular joints. Acta Radiol. (Stockh.) 4, 273-288.
UOTILAE. (1964) The temporomandibular joint in adult rhemumatoid arthritis. Acta Odontol. Stand. (Sup&
39) 22,17.
WRIGHT V. (1959) Rheumatism and psoriasis; a re-evaluation. Am. J. Med. 27,45#62. WRIGHT V. (1961) Psoriatic arthritis. A comparative radiographic study of rheumatoid arthritis and arthritis associated with psoriasis. Ann. Rheum. Dis. 20, 123-132.
of Dentistry,
4, 123-l
28
Psoriatic arthritis and the temporomandibular joint G. Stewart Blair,
MIX,
FDS, HDD
Department of Oral Surgery, The Dental School, University of Newcastle upon Tyne ABSTRACT The clinical and radiological changes produced by psoriatic arthritis in the temporomandibular joints of 7 patients are described. There are few references in the literature to such changes, owing, perhaps, to the comparative rarity of this condition and to the difficulty of examining these joints radiologically. The possibility of the progression of Reiter’s disease to psoriatic arthritis is mentioned. The changes described are in many ways similar to those produced by rheumatoid arthritis. It is important that patients who display such abnormalities but are known not to be suffering from rheumatoid arthritis should be properly investigated for psoriatic arthritis.
INTRODUCTION PSORIATICarthritis
is defined on the triad of (a) psoriasis, (b) radiological erosive polyarthritis and (c) a negative serological test for rheumatoid factor (Boyle and Buchanan, 1971). It is, therefore, an entity quite distinct from rheumatoid arthritis. This distinction is further marked by the simultaneous occurrence of both joint and skin manifestations in many instances, by characteristic radiological appearances, by the absence of subcutaneous nodules and by the fact that psoriatic arthritis affects males more frequently than females. It has, however, been suggested that the structural changes produced in both conditions may be very similar (Wright, 1961; Lundberg and Ericson, 1967). The first report that psoriatic arthritis could affect any of the oral structures was published only 11 years ago (Lundberg, 1965). In the
same year Franks (1965) reported another case. The largest study to date (Lundberg and Ericson, 1967) which consisted of I1 cases, was also related to the temporomandibular joints. The temporomandibular joints of 7 patients suffering from psoriatic arthritis were examclinically and radioined, coincidentally, logically during the course of a study of adult rheumatoid arthritis previously reported by Chalmers and Blair (1973). Although the number involved is small it is felt to be important to detail the results of these examinations. This conclusion has been reached not only in view of the paucity of information on the subject in the literature but also because further evidence is provided to bear out the contention that the changes discovered in the psoriatic arthritic temporomandibular joint may be mistaken for those of rheumatoid arthritis.
PATIENTS
AND
METHODS
Seven patients with psoriatic arthritis were examined. Their disease was of sufficient severity to warrant outpatient attendance at a specialist centre. Otherwise the patients were unselected. There were 4 females and 3 males whose ages varied from 43 to 67 years (mean 53.8 years). The duration of the disease ranged from 6 months to 21 years (mean 4.8 years) and the ages of the patients at the time of onset of the disease from 28 to 66 years (mean 49.2 years). All had negative serological tests for rheumatoid factor and satisfied the definition of psoriatic arthritis.
124
Journal of Dentistry, Vol. ~/NO. 3
Clinical examination of the temporomandibular joint
This was completed at the same time as the temporomandibular joint examination. Its purpose was to ascertain whether or not dental abnormalities might be responsible for any of the temporomandibular joint abnormalities discovered.
‘rheumatic’ condition. The positions of the mandibular condyle were considered first. With the teeth in occlusion, the position of the condylar head in the articular fossa was designated ‘normo-‘, ‘antero-‘, or ‘retro-‘. If the condylar head was not lying within the fossa ‘subluxation in the closed position’ was said to be present. An interarticular space of less than 0.5 mm was regarded as ‘reduced’ (Madsen, 1966). With the mouth maximally open, a reading of -4.0 mm or less was considered to indicate ‘reduced mobility’ and of +4*0 mm or more ‘increased mobility’, according to the criteria of Madsen (1966). ‘Increased mobility’ was not considered to be an abnormality unless there were associated clinical features, when it was described as ‘subluxation in the open position’. Fibrous or bony ankylosis was also sought. The condition of the calcified structures was then evaluated. The following were classed as abnormalities: sclerosis of one or other of the articular surfaces; surface and pocket erosions; flattening of the mandibular condyle or articular eminence; marginal proliferations of the condylar head; subchondral cysts and calcification of the articular disc. The presence of osteoporosis was recorded but was not regarded as an abnormal finding (Lundberg and Ericson, 1967).
Radiological examination of the temporomandibular joint
Comparison with rheumatoid arthritis
The 14 joints were radiographed in the normally occluded and maximally open positions using circular tomography. This examination was repeated or, alternatively, either orthopantomography or lateral transcranio-oblique radiography was used if there was any doubt in the interpretation of any radiograph.
Chalmers and Blair (1973) suggested that. clinically, limitation of opening, stiffness; crepitus, referred pains and tenderness on biting were significantly more common among patients with adult rheumatoid arthritis than among control patients, with tenderness on palpation and pain being present more frequently but not quite significantly so. In addition, Anderson and Blair (1975) have recently described a method of scoring the features seen on temporomandibular joint radiographs in an attempt to distinguish a rheumatoid arthritic from a normal population. The 7 psoriatic arthritic patients were similarly screened to determine further any similarities in the changes produced in the temporomandibular joints of patients suffering
This examination was performed as described by Chalmers and Blair (1973). The presence or absence of the following abnormal features was recorded: deviation of the mandible from the midline during opening and closing movements; limitation of opening; subjective stiffness of the joint; joint crepitus on palpation; audible or palpable clicking of the joint detected objectively; subjective joint clicking; pain in the joint itself, referred pain or tenderness of the joint on biting or chewing; tenderness of the joint, joint capsule or muscles of mastication detected by palpation while the patient was performing the full range of mandibular movements; past history of, or presence of, soft-tissue swelling external to the temporomandibular joint; subluxation. A history of any abnormality which was considered to be in any way doubtful was not accepted.
Clinical examination mouth
Radiological
of the
interpretation
All the radiographs were examined ‘blind’ and in random order by a single observer. This feature was facilitated by the fact that these radiographs were included, haphazardly, among a large number of radiographs of patients with rheumatoid arthritis and primary osteoarthrosis as well as other systemic conditions, and also of patients with no detectable
125
Blair: Psoriatic Arthritis and Temporomandibular Joint Tab/e /.-Summary
of clinical
and radiological
No. of patients
Clinical feature Deviation Limitation of opening Stiffness Audible click (subjective Palpable click Pain Referred pain Tenderness on biting Tenderness on palpation
and objective)
Total with abnormalities Total with either clinical or radiological One patient One patient One patient He had no overclosure
features recorded
5 abnormalities
No, of patients
No. of joints
Antero-position Retro-position Reduced mobility Subluxation (closed) Surface erosions Flattening Calcified disc Osteoporosis-total Osteoporosis alone
4 1 2 1 2 2 1 3 1
6 2 2 2 2 3 1 5 2
Total with abnormalities or both, 6 patients
5
7
Radiological feature
with several clinical abnormalities had no radiological abnormalities. with a number of radiological abnormalities had no clinical abnormalities. in addition complained of tenderness on palpation and pain of his right temporomandibular joint. other clinical or radiological abnormalities of either joint. These symptoms may have been due to and a poor occlusion and, accordingly, he was classified as ‘normal’.
from either arthritis.
rheumatoid
arthritis
or psoriatic
RESULTS The results of the examinations are summarized in Tables I and II. Table I details only the clinical and radiological features recorded. Features sought but not recorded are excluded. Clinical abnormalities were present in 6 patients, but one (patient 6) was excluded from the final total because his complaints were probably associated with his unsatisfactory dentures. Radiological abnormalities were seen on the radiographs of 5 patients (Figs. I, 2 and 3), 4 of whom also had clinical abnormalities. either clinical or radiological Therefore, abnormalities or both were recorded for 6 of the 7 patients. Table ZI compares the recorded features with those found significantly more frequently in a rheumatoid arthritic than a normal population. The patient with the lowest radiological score also displayed the greatest number of clinical abnormalities. However, the patient with the second lowest radiological score appeared to be normal clinically, and the patient with the next lowest displayed only one clinically abnormal feature. On the other hand, the patients with a score of +0*8 presented with
Table //.-Scoring of clinical and radiological abnormalities detected as possible features of rheumatoid arthritis
Patient
1 2 3 4 5 6 7
Clinical abnormality present * Yes No Yes Yes Yes No Yes
Radiological score t (normal or maximum + 1 .l ) +0.8 -2.7 --7.6 i-l.1 iO.8 t1.1 - 1.1
*Primarily, limitation of opening, stiffness, referred pain and tenderness on biting. Secondary tenderness on palpation and pain. $Score .S = 1~1-0~3a-1~2b-1~8c-3~5d-2~3e-1~9f-2~4g. where a represents antero-position, b reduced mobility, c subluxation in the closed position, d surface erosions, e pocket erosions, f flattening and g marginal proliferations (Anderson and Blair, 1975).
one primary and one secondary and two primary and one secondary clinical abnormalities respectively. Also, one patient with a normal radiological score was found to have one primary and one secondary abnormal clinical features. The seventh patient (patient 6) has already been mentioned.
126
Fig.
Journal of Dentistry, Vol. ~/NO. 3
I.-Antero-position
of the condylar head
Fig. 3.-Reduced mobility of the left condyle with the mouth held as widely open as possible. Surface erosions are also evident.
DISCUSSION The temporomandibular joints of 7 patients with psoriatic arthritis have been studied clinically and radiologically. These examinations were completed without prior knowledge of the underlying condition. This was readily achieved as the 7 patients were included in a total of 219 patients, each of whom was examined in exactly the same manner. The majority of these patients suffered from rheumatoid arthritis, and two other large groups comprised osteoarthritic and normal patients. All the examinations were completed by one person. The radiographic techniques used have been shown to be very suitable for examining the temporomandibular joint (Blair
Fig.
2.-The condyle is in retro-position and also demonstrates surface erosions.
and Chalmers, 1972; Blair et al., 1973). The prevalences of both clinical and radiological changes were found to be high. In addition, many of the changes discovered were similar to those which experience would lead one to suspect a diagnosis of rheumatoid arthritis. Only 7 patients were examined. This is, however, the second largest series reported. One reason for this may be the relative rarity of the condition. Psoriasis is found in only about 2 per cent of the adult population of northern Europe and North America (Baker, 1966). The incidence of polyarthritis in psoriatic population samples is an estimated 7 per cent in hospital series (Baker, 1975). Another reason is the lack of study, especially radiological, of arthritis and arthrosis of the temporomandibular joint. The very position of the joint in relationship to the skull has compounded this problem (Uotila, 1964). In addition, the present series would appear to be the first to detail the clinical and radiological findings and to compare and contrast these with changes which have been described in rheumatoid arthritic populations. It might be thought an example ofchance that 6 of the 7 patients examined showed temporomandibular joint changes. After all, only 39 of the 95 control patients in the investigation of Chalmers and Blair (1973) of patients with rheumatoid arthritis had temporomandibular joint changes. If their figures are analysed, however, it can be seen that at most 10 of the control patients exhibited what have been
Blair: Psoriatic Arthritis and Temporomandibular Joint
127
quite usual percentage for a normal population described as primary abnormalities, compared -were so affected in the present series. with 5 of the total of 7 psoriatic arthritic Such changes and differences are not patients. The clinical changes in these two unexpected. Wright (1959) described three groups, therefore, are different in character. patterns of psoriatic arthritis, the third of Exactly the same can be said for the radiowhich closely resembles rheumatoid arthritis logical changes. Only 2 of a total of 83 control clinically although tending to involve fewer patients studied by Anderson and Blair (1975) joints and to be less disabling. This would had a score less than ~ 1.0, and only 39.8 per largely accord with the findings in the present cent produced a score less than the maximum of -t 1.1. Three of the 7 patients in this stfi~dJ%XZl series. Wtight’s second pattern is deforming, may involve any joint and occurs in a younger scores of - -7.6, -2.7 and - 1.1 respectively, age group. Interestingly, the patient in the and 2 more had a score less than the maximum. present series who showed the largest number Thus, 71.4 per cent had scores of less than and greatest severity of abnormalities had -:-1.1. On the other hand, by the same reasoncontracted the disease at the earliest age and ing it can be understood that many of the had suffered from it over the longest period. changes produced by psoriatic arthritis must More of the patients reported by Lundberg and be similar to those produced by rheumatoid Ericson (1967) may have fallen into this arthritis. A further similarity between these pattern. Indeed, the age range of their patients two diseases is the reasonably good correwas17-64years(mean39.Oyears),comparedwith lation between the clinical and radiological 43-67 years (mean 53.8 years) in this series. findings (Table 111). One clinical abnormality Boyle and Buchanan (1971) discussed how which may be seen more commonly among Reiter’s disease may progress to a picture patients with psoriatic arthritis is deviation clinically indistinguishable from psoriatic arthof the mandible during opening and closing ritis after repeated attacks in a very small movements. number of patients. One 27-year-old man with Reiter’s disease was examined, and it is of Tab/e l//.--Relationship between clinical and interest to note that the clinical tempororadiological status mandibular joint abnormalities recorded inClinical Radiological No. % cluded stiffness, crepitus, pain, deviation and status status audible and palpable clicking as well as radioAbnormal Abnormal 4 57.1 logical reduced mobility of the left condyle. Abnormal Normal 1 14.3 These abnormalities, with the exception of Normal Abnormal 1 14.3 crepitus, were among those discovered most Normal Normal 1 14.3 frequently among the 7 psoriatic arthritic patients of the present series. Lundberg and Ericson (1967) also described In conclusion, it may be stated that involvemany radiological abnormalities affecting the ment of the temporomandibular joint by temporomandibular joints of 11 patients psoriatic arthritis would appear to be common suffering from psoriatic arthritis whom they and that this involvement may closely resemble studied. In fact, the incidence of radiological that of rheumatoid arthritis. If such changes changes was higher and their severity greater are discovered and the investigations for than was seen in the present series. Although rheumatoid arthritis prove to be negative it they do not provide a breakdown of their must not be concluded that the patient is free results, at least 9 of their 11 patients must have of an underlying systemic condition which had a radiological score of - 1.2 or less. They could be responsible for the temporomandialso stated that osteoporosis, in combination bular joint arthritis. Although similar in some with at least one other observable change, was respects, rheumatoid arthritis and psoriatic seen in 55.5 per cent of the joints in their study, arthritis are different entities requiring different
128
Acknowledgements I wish to thank Miss A. Carson for the cheerful and unfailing production of excellent radiographs, Professor W. Watson Buchanan for his advice and encouragement and Mrs M. Burton for invaluable secretarial assistance.
REFERENCES ANDERSONJ. A. and BLAIR G. S. (1975) Screening in a dental clinic for adult rheumatoid arthritis involving the temporomandibular joint using a statistical discriminant function. J. Oral Rehabil. 2, 187-197.
BAKER H. (1966) Epidemiological aspects of psoriasis and arthritis. Br. J. Dermatol. 78, 249261.
BAKER H. (1975) Psoriasis. Br. J. Hosp. Med. 13, 547-563.
BLAIRG. S. and CHALMERSI. M. (1972) Radiology of the temporomandibular joint. J. Dent. 1, 69-76.
BLAIR G. S., CHALMERSI. M., LEGGAT T. G. and BUCHANANW. W. (1973) Circular tomography of the temporomandibular joint. Oral Surg. 35, 416427.
Journal of Dentistry,
Vol. ~/NO. 3
BOYLEJ. A. and BUCHANANW. W. (1971) Clinical Rheumatology. Oxford, Blackwell, pp. 304-317. CHALMERSI. M. and BLAIR G. S. (1973) Rheumatoid arthritis of the temporomandibular joint. Q. J. Med. 42,369-386. FRANKSA. S. T. (1965) Temporomandibular joint arthrosis associated with psoriasis. Oral Surg. 19, 301-303. LUNDBERG M. (1%5) Rijntgendiagnostik vid kakledsbesvar. Odontol. F&en. Tidsskr. 29, 209240.
LUNDBERGM. and ERICSONS. (1967) Changes in the temporomandibular joint in psoriasis arthropathica. Acta Derm. Venereol. (Stockh.) 47, 354-358.
MADSENB. (1966) Normal variations in anatomy, condylar movements and arthrosis frequency of the temporomandibular joints. Acta Radiol. (Stockh.) 4, 273-288.
UOTILAE. (1964) The temporomandibular joint in adult rhemumatoid arthritis. Acta Odontol. Stand. (Sup&
39) 22,17.
WRIGHT V. (1959) Rheumatism and psoriasis; a re-evaluation. Am. J. Med. 27,45#62. WRIGHT V. (1961) Psoriatic arthritis. A comparative radiographic study of rheumatoid arthritis and arthritis associated with psoriasis. Ann. Rheum. Dis. 20, 123-132.
