SECTION
EDITOR
iner comparison of bone scintigraphy oramic radiography of temporomandibular with signs and symptoms Francis M. Bush, PhD, DMD,a Walter G. Harrington, Stephen W. Harkins, PhDC Medical College of Virginia, College of Dentistry, Richmond, Va.
j
DDS,b and
Panoramic radiographs of the temporomandibular joints of patients with orofacial pain were examined for evidence of pathology by three different groups of four dental specialists and by a group of four general dentists. Bone scans of the same joints were used as the “gold standard” for identification of disorder and indicated a low rate of correct readings by the four professional groups. When the symptomatic side of the complaint was used as the gold standard, there was no statistically significant association with the bone scan observations. Comparative analysis of other patient symptoms showed little agreement with panoramic radiographs and scintigraphs. Reliability estimates may be highly variable, even among clinical experts. These results show that neither radiologic technique would be definitive for diagnosis of TM disorders. (J PROSTHET DENT 1992;67:246-51.)
emporomandibular (TM) disorders are classified on the basis of self-reports by patients, from objective clinical findings, and by analysis of bony contours of the TM joints as observed from radiographs. The 1982 American Dental Association President’s Conference Report stated that where there is reason to believe organic pathology exists, radiographs of the TM joints should be taken.l That report, and a summary statement made by 11 prominent members at the 1989 Conference for the American Academy of Pediatric Dentistry,2 recommended either a panoramic, transcranial, or transpharyngeal radiograph may be used as an initial imaging technique. A recent review of 26 different studies involving malignancies associated with TM disorders indicates that screening radiographs should be obtained for diagnostic purposes.3 While panoramic radiography reveals much less about joint morphology than multidirectional tomography,4, 5 it is used routinely in dental offices because there is minimum superimposition of other bony structures over the condyles of the joint. Performance of the panoramic analysis with the mandible in open and closed positions enhances visualization of the joint anatomy. Another radiologic technique indicated as being useful in evaluating TM joint disorders is radionuclide bone scin-
aProfessor, Director TMJ-Facial Pain Center, Restorative Dentistry. bAssociate Professor, Department of Restorative CProfessor, Department of Gerontology. 10/P/32995
Department Dentistry.
of
tigraphy. Scanning with technetium diphosphonates provides a functional display of bony metabolism and improves interpretation of joint pathology.6, 7 When the joint undergoes osteogenic activity, the scan shows uptake of technetium. This change makes the scan a particularly sensitive tool for earlier diagnosis than can be acquired with a standard radi0graph.s Panoramic radiography has been used routinely for screening TM disorders, but scintigraphy has not. Furthermore, interexaminer reliability in diagnosing TM joint pathology has not been determined with either technique. We therefore sought to evaluate the reliability and validity of using scintigraphy to identify adaptive changes of the TM joints. The present study had four aims: to show whether interpretation of panoramic radiographs differed among various groups of dental specialists and general practitioners; whether readings of panoramic radiographs differed from readings made of bone scans; whether technetium uptake correlated with the symptomatic side of the complaint; and whether other clinical signs and symptoms correlated with the radiologic techniques. METHODS
AND
MATERIALS
Fifteen patients (12 women and 3 men) who presented to the TMJ-Facial Pain Center at Virginia Commonwealth University School of Dentistry with signs and symptoms that could be categorized into classic syndromes of myogenous and arthrogenous TM disorders were selected for this study. The mean age of the patients was 39.6 (range, 18 to 70) years. They all had been referred to the Center, a regional clinic for the diagnosis and treatment of patients with various kinds of orofacial pain, The severity of-the
FEBRUARY
1992
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NULMBER
2
BONE
Table
SCAN
AND
RADIOGRAPHIC
I[. Examiners’
Group Q.S. Q.P. Pros.
6. Dent. F (3, 16)*
TMJ
DIAGNOSIS
judgments of panoramic radiograph using bone scan as the “gold standard” True positive rate
False positive rate
True score
a,
a
Sensitivity
Specificity
0.69 0.45 0.68 0.61 1.48
0.45 0.18 0.38 0.45 1.12
0.24 0.26 0.30 0.17 0.32
0.64 0.76 0.78 0.42 0.46
0.89 1.48 0.93 0.97 0.25
0.69 0.45 0.68 0.61 1.48
0.55 0.80 0.52 0.53 1.08
O.S., Oral surgeons; O.P., oral pathologists; Pros. prosthodontists; *F, Analysis of variance; df, number in parentheses.
G. Dent. general dentists.
physical complaints was therefore likely to have been greater than that encountered in the general population. Each patient completed a health history questionnaire that included questions about the location of the pain. They signed a consent form and were examined for jaw limitation on movement, deviation of the mandible on mouth opening, tenderness of the masticatory muscles and TM joints on digital palpation, joint sounds, and tooth wear. Details of the questionnaire and the methods for examination have been previously published9 in detail. Panoramic radiographs were made of the TM joints of all patients at open and closed positions of the mouth. Three groups of dental specialists (fixed prosthodontists, oral pathologists, and oral surgeons) and one group of general dentists reviewed the panoramic radiographs. Each group consisted of five examiners. The 20 dentists were blinded to the status of the patient’s history and symptoms. Scintigraphy of all 30 TMJ was performed using 22.0 mC: of technetium-99m methyl diphosphonate given by intravenous administration. Images were obtained approximately 3 hours after injection, using a conventional gamma scintillation camera. They were reviewed by the same staff radiologist who was also blinded to the status of the patient’s history and symptoms. Signal Detection Theory (SDT)“, l1 was used to provide an estimate of the examiner’s accuracy in discriminating differences between joints, as well as in obtaining an estimate of the examiner’s response bias. SDT provides an unbiased estimate of discrimination accuracy, designated as d’, representing here the examiner’s ability to identify joints that were pathologic based on the panoramic radiographs where the bone scan was accepted as the “gold standard.” Higher values of d’ indicated greater agreement between judgments made of panoramic radiographs and the results obtained with the bone scans. Lower d’ values represented lesser agreements. The index of the examiner’s bias, designated as /?,reflected the willingness of the examiner to label a panoramic radiograph as pathologic when the bone scan was used as the “gold standard.” Higher values of p indicated less willingness to label the panoramic radiograph as pathologic, while lower /3 values indicated a relatively greater tendency toward identifying a panoramic radiograph as pathologic. Thus SDT permitted separate
THE
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evaluations for accuracy and response bias for the different examiners. Further distinctions between panoramic radiographs and bone scans and between the symptomatic side and bone scans were analyzed using sensitivity and specificity measures. Such measures have often been employed in epidemiologic studies of screening and diagnostic tests.i2 Sensitivity, or the true positive rate, was defined as the probability of correct identification of a case or all of the true positives divided by all those with pathology. Specificity was defined as the true negative responses divided by all responses without pathology. RESULTS Radiologic
findings
Table I summarizes the results for accuracy of judgments made about the panoramic radiographs in relation to the bone scans. In this case, a correct identification or true positive was obtained when the panoramic radiograph was judged to indicate pathology when the technetium uptake of the bone scan was used as the “gold standard.” False positives were defined as a judgment of pathology when the bone scan was within normal limits. Accuracy or agreement between judgments made by examiners was thus a function of both the true and false positive rates. The results showed that the four professional groups did not differ significantly on either true or false positive rates (Table I, Fig. 1). The four groups did not differ significantly using the true score, another index of accuracy. This index represented the true positive rate minus the false positive rate and corrected for chance success. The SDT indices of accuracy (d’) and response bias (p) are summarized for each group of examiners (Table I, Fig. 2). While the groups did not differ statistically with respect to either d’ or 0, their overall accuracy was low. This low accuracy was represented by plotting the average value for each group in the receiver operating space (Fig. 3). This space was defined by plotting the true positive rate on the y axis and the false positive rate on the x axis. Nearness of these values to the positive diagonal line indicated low discrimination ability on the part of the examiners. Put another way, the further each group’s position was from this line the greater the ability to discriminate. The posi-
247
BUSH,
=
TRUE
+
FALSE
-TRUE scoRE
1.00 0.90
0.80 0.70 0.60 P $
0.50 0.40 0.30 0.20 0.10 0.00 1
2
3
4
GROUPS Fig. 1. Comparison of true, false, and true score rates for these groups: 1, oral surgeons; 2, oral pathologists; 3, prosthodontists; and 4, general dentists.
ROC
ANALYSES groups 2
llil
d’
Ez33
ET24
beta
Fig. 2. Receiver operating characteristics (ROC) analysis showing d’ and @values for groups described in Fig. 1.
248
HARRINGTON,
AND
WARKINS
tion of points in the receiver operating space also indicated that the examiners were relatively unbiased in their judgments concerning the panoramic radiographs. That is, the pattern of points around the negative diagonal line indicated that the examiners were adopting neither a lax nor a strict set of responses. The magnitude of this low agreement between examiners’ readings of panoramic radiographs versus results for the bone scans is further indicated by the sensitivity and specificity measures (Table I, Fig. 4). In the present study, the values for sensitivity and specificity did not differ statistically between any of the professional groups. The values were equally low across all groups. A series of analyses parallel to those reported between the panoramic radiographs versus the bone scans was computed with the patient complaint as the “gold standard” and the bone scan results as the “experimental” data. This effectively asks the question, “What is the accuracy of the bone scan results in discriminating jaws with symptoms versus jaws without symptoms?” These results indicated that the accuracy of the bone scan results for identification of the symptomatic side was not significantly greater than the ability of the examiners to judge pathology on the panoramic radiographs. Both sets of results were equally inaccurate (compare Tables I and II). Clinical
findings
Tables III and IV show the signs and symptoms useful for differential diagnosis of the patients. Ten patients had then symptoms classified as mixed myogenous-arthrogenous disorders. Five (patients No. 4, 7, 8, 10, and 11) of them had greater tendencies toward myogenous involvement than arthrogenous involvement. This diagnosis was based primarily on the widespread tenderness of the masticatory and neck muscles to palpation. Two patients had negative bone scans, but the joints had reducible clicks. Three had positive bone scans; one had recently been involved in an automobile accident, one had unilateral clicking with reduction, and the third had no history of joint sounds and none at examination. Five (patients No. 1,2,3, 5, and 9) others had tendencies toward complex disk derangement. Two of these patients had closed lock conditions. Their bone scans were negative. One had localized tenderness only of the joint area; the other had a more diffuse pattern of muscular tenderness. The remaining three patients had positive bone scans; the joints clicked with reduction. The final five patients had the following diagnoses: four (patients No. 6, 13, 14, and 15) had primarily degenerative joint disease classifiable by the presence of either bilateral joint popping or coarse crepitus and little myogenous involvement. Their bone scans were positive. The last patient (No. 12) had trigeminal neuralgia and responded successfully to treatment with carbamazepine (Tegretol; Geigy Pharmaceuticals, Ardsley,
FEBRUARY
1992
VOLUME
67
?.JUMBER
2
RONE
SCAN
AND
RADIOGRAPHIC
TMJ
DIAGNOSIS
\ .9 ? d
\\
.8 t
\
1.28 \
\
\
1.0
0.05
.I FALSE
*
I lllll
2
.3
.4
POSITIVE
Fig. 3. Receiver operating characteristics atic side for groups described in Fig. 1.
Table
II.
.6
.7
I I
.8
.9
RATE
analysis comparing bone scan with symptom-
Comparison of bone scan using side with symptoms as the “gold standard”
True positive rate
False positive rate
True score
d’
B
Sensitivity
0.67
0.44
0.23
0.57
0.92
0.67
N.Y.), yet he bad considerable tenderness to digital palpation. Deviation ofthe mandible on opening, symptomatic side, and bone scan were not significantly related (Table III). Just two patients with myogenous involvement, one with disk derangement, and none with degenerative joint disease had mandibular deviation associated with the symptomatic side, which was unrelated to the bone scan. No significant relationship existed between the presence of tooth wear, the bone scan, and the diagnostic category (Table III). Eight patients had minimal to no wear, four of whom had arthrogenous involvement (disk or degenerative joint disease) greater than myogenous involvement. Five (patients No. 5,8,10,14, and 15) had extensive tooth wear; three had pri”marily arthrogenous involvement and two primarily had myogenous involvement. DISCUSSION The findings of the present study indicate a remarkable lack of agreement between the panoramic radiographic readings in relation to the bone scans. This lack of agree-
THE
.5
-1.28
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OF PROSTHETIC
DENTISTRY
Specificity 0.56
ment may be caused by ambiguity of the panoramic radiograph presenting pathology of the joint, ambiguity of the bone scan findings in relation to joint changes sufficient to be apparent on the panoramic radiograph, or because of a combination of both. Clearly, these results of the bone scan findings represent a poor “gold standard” to interpret reports of articular changes. The inability to associate the symptomatic side with positive bone scan results further reflects this lack of agreement. In a random survey of 114 individuals from the general population, unequivocal technetium uptake occurred in 4 % of the TM joints.r3 Marked uptake in these few patients was associated with the presence of self-reported TM joint complaints, but TM joint complaints were present in only 50% with less marked uptake. The authors summarized the results of four other studies and concluded that an increased uptake was significant as an incidental finding of suspect TM joints. Results of other studies using different imaging techniques have shown the difficulty of relating radiographic findings to diagnosis. Interexaminer analysis of transcranial radiographs by six different clinicians showed no sig-
249
BUSH,
Table
III.
27
12 13
F F F F F F F F F F F F M
14
M
15
M
1
5
6 7 8
9 10 11
L, left; R, right;
IV.
Maximum opening (mm)
Age (Yr)
Sex
2 3 4
Table
Mandibular deviation
23 20 64 55 31
49 35 29
32 64
39 45
37 33 20
40 37 35 45
N N
70 43
43 36
N L
60
B, bilateral;
-, minimal;
B L B R L B R L B R R L B R B
N
L N N
R L N
L L
Joint noise
1
Locked
2 3 4
Locked Popping, reciprocal B Clicking B
5
Popping L, Lt B
6 7
Crepitus, coarse R Clicking R
8
Clicking L
9 10
Clicking, soft L Clicking, reciprocal R
11
N
12
N
13 14 15
Clicking, reciprocal B Popping, reciprocal B Popping, reciprocal B R, right;
scan
Tooth
B L B B B B B B L L
wear
+ + + + + +
of study to palpation
Right
Left
Auditory meatus, lateral joint surface, masseter B Masseter, temporalis B, medial pterygoid B Lateral joint surface B, masseter B, temporalis B, pterygoids B, sternocleiodmastoid B Masseter B, temporalis B, medial pterygoid B, neck, posterior B, sternocleidomastoid Lateral joint surface Masseter B, temporalis B, pterygoids B, neck, posterior B, sternocleidomastoid B Auditory meatus B, masseter B, temporalis B, pterygoids B, neck, posterior B, sternocleidomastoid B, Temporalis, pterygoids B, neck, posterior B Masseter, temporalis, pterygoids, sternocleidomastoid, Auditory meatus B, lateral joint surface B, masseter B, pterygoids, neck, posterior B, sternocleidomastoid-B
Auditory meatus, lateral joint surface Lateral joint surface
Lateral pterygoid
Auditory meatus, lateral joint surface, temporalis, medial pterygoid, neck, posterior
L, left; Lt, laterotrusion;
Masseter, pterygoids Medial pterygoid B Lateral joint surface N, normal.
nificant correlation between readability of radiographs and radiologic diagnosis of TM disorders.r4 The radiographs were read from 25 patients with a long-term history of TM disorders and from 25 individuals free of symptoms. 250
HARKINS
f, bruxism.
Tenderness
B, Bilateral;
Bone
Complaint
L L
24 28 51 46
18
Parameters
Patient No.
-
AND
Study parameters
Patient NO.
N, None;
HARRINGTON,
Among 102 patients with TM disorders, condyle position was broadly distributed at all positions for arthrosis patients.lj The position on the contralateral side in patients with unilateral symptoms was similar to the position FEBRUARY
1992
VOLUME
67
NUMBER
2
BONE
SCAN
AND
RADIOGRAPHIC
TMJ
DIAGNOSIS
SCREENINQ
ANALY3ES
groups I
2
izms
LxxJr
initial diagnosis of TM disorders. In the case of scintigraphs, their use must be weighed against the cost of this procedure. SUMMARY
0.60
Four groups of dental specialists and one group of general dentists evaluated panoramic radiographs of 30 TM joints for pathology. Comparison with bone scintigraphs of the same joints showed no statistical difference among examiners. No signs or symptoms of the patients with orofacial pain correlated with the panoramic radiographs or the scintigraphs.
0.50
REFERENCES
0.80
0.40 0.30 020 0.10
0.00 SUJSiTiVlTY
SPECIFICITY
Fig. 4. Comparison of sensitivity for groups described in Fig. 1.
and specificity values
of the main symptom side in each diagnostic category. In another study, three dentists and a medical radiologist examined a total of 150 tomograms and lateral transcranial projections of patients with TM disorders and concluded that a high percentage were impossible to interpret, and that interexaminer reliability was low even with the same technique.r6 The clinical findings further demonstrate the difficulty of using either the bone scans or the panoramic radiographs for diagnostic purposes. No important association was made with either the radiologic technique and any sign or symptom. Our findings agree with the conclusion made in a major review involving the relationship between bone scanning and metabolic bone disease that this technique is a significant research tool, but its role in clinical practice has not been established.7 This overall lack of reliability further demonstrates that panoramic radiographs and scintigraphs would be useful for diagnosis only for gross morphologic or adaptive changes in form. In the case of panoramic radiography, the statement has been made that panoramic radiography should have a limited role in dental school screening clinics.17 Also, this conclusion supports the statement made in the Report of the 1989 Committee on Scientific Investigation of the American Academy of Restorative Dentistry,ls that conventional radiologic examination is of limited use in the
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1. Griffith RH. Report of the President’s Conference on the examination, diagnosis and management of temporomandibular disorders. J Am Dent Assoe 1983;106:75-7. 2. American Academy of Pediatric Dentistry. Treatment of temporomandibular disorders in children: summary statements and recommendations. J Am Dent Assoc 1990;120:265-9. 3. Bavitz JB, Chewning LC. Malignant disease as temporomandibular joint dysfunction: review of the literature and report of case. J Am Dent Assoc 1990;120:163-6. 4. Yune HY. Roentgenologic diagnosis in chronic temporomandibular joint dysfunction syndrome. CRC Crit Rev Clin Radio1 Nucl Med 1973;1(4):161-75. 5. Raustia AM, Pyhtinen J. Morphology of the condyles and mandibular fossa as seen by computed tomography. J PROSTHET DENT 1990;63:7783. 6. Alexander JM, Fratkin MJ, Hall DL. Temporomandibular joint marking for radionuclide bone scintigraphy. J Oral Surg 1979;37:753-4. 7. Fogelman I. Bone scanning and photon absorptiometry in metabolic bone disease. Baillieres Clin Endocrinol Metab 1988;2:69-86. 8. Alexander JM. Radionuclide bone scanning in the diagnosis of lesions of the maxillofacial region. J Oral Surg 1976;34:249-56. 9. Bush FM, Whitehill JM, Martelli MF. Pain assessment in temporomandibular disorders. J Craniomandib Pratt 1989;7:137-43. 10. GreenDM, Swets JA. Signal detection theory and psychophysics. Huntington, NY: Robert E Krieger, 1974479. 11. Metz CE. Rot methodology in radiologic imaging. Invest Radio1 1986;21:720-33. 12. Mausner JS, Kramer S. Epidemiology-an introductory text. Philadelphia: WB Saunders, 1985:361. 13. Epstein DH, Graves RW, Higgins WL. Clinicai significance of increased temporomandibular joint uptake by planar bone scan. Clin Nucl Med 198?;12:705-7. 14. Wise H, Rely R, Barghi N. Radiographic diagnosis of TMJ dysfunctions: effect of readability [Abstract]. J Dent Res 1984;63:332. 15. Pullinger AG, Solberg WK, Hollender L, Guichet D. Tomographic analysis of mandibular condyle position in diagnostic subgroups of temporomandibular disorders. J PROSTHET DENT 1986;55:723-9. 16. Van Den Berghe LI, De Boever J, Veys R, Allewaert J. Inter-examiner reliability of radiographic diagnosis in TMJ-dysfunction [Abstract]. J Dent Res 1986;65:821. 17. Kantor ML, Slome EA. Efficacy of panoramic radiography in dental diagnosis and treatment planning. J Dent Res 1989;68:810-2. 18. Phillips RW, Jendresen MD, Klooster J, McNeil C, Preston JO, Schalihorn RG. Report of the Committee on Scientific Invest.igation of the American Academy of Restorative Dentistry. J PROSTHET DENT 1989;62:70-109.
Reprint
requests to:
DR. FRANCIS M. BUSH Box 566, MCV STATION RICHMOND, VA 23298
251
EDITOR
iner comparison of bone scintigraphy oramic radiography of temporomandibular with signs and symptoms Francis M. Bush, PhD, DMD,a Walter G. Harrington, Stephen W. Harkins, PhDC Medical College of Virginia, College of Dentistry, Richmond, Va.
j
DDS,b and
Panoramic radiographs of the temporomandibular joints of patients with orofacial pain were examined for evidence of pathology by three different groups of four dental specialists and by a group of four general dentists. Bone scans of the same joints were used as the “gold standard” for identification of disorder and indicated a low rate of correct readings by the four professional groups. When the symptomatic side of the complaint was used as the gold standard, there was no statistically significant association with the bone scan observations. Comparative analysis of other patient symptoms showed little agreement with panoramic radiographs and scintigraphs. Reliability estimates may be highly variable, even among clinical experts. These results show that neither radiologic technique would be definitive for diagnosis of TM disorders. (J PROSTHET DENT 1992;67:246-51.)
emporomandibular (TM) disorders are classified on the basis of self-reports by patients, from objective clinical findings, and by analysis of bony contours of the TM joints as observed from radiographs. The 1982 American Dental Association President’s Conference Report stated that where there is reason to believe organic pathology exists, radiographs of the TM joints should be taken.l That report, and a summary statement made by 11 prominent members at the 1989 Conference for the American Academy of Pediatric Dentistry,2 recommended either a panoramic, transcranial, or transpharyngeal radiograph may be used as an initial imaging technique. A recent review of 26 different studies involving malignancies associated with TM disorders indicates that screening radiographs should be obtained for diagnostic purposes.3 While panoramic radiography reveals much less about joint morphology than multidirectional tomography,4, 5 it is used routinely in dental offices because there is minimum superimposition of other bony structures over the condyles of the joint. Performance of the panoramic analysis with the mandible in open and closed positions enhances visualization of the joint anatomy. Another radiologic technique indicated as being useful in evaluating TM joint disorders is radionuclide bone scin-
aProfessor, Director TMJ-Facial Pain Center, Restorative Dentistry. bAssociate Professor, Department of Restorative CProfessor, Department of Gerontology. 10/P/32995
Department Dentistry.
of
tigraphy. Scanning with technetium diphosphonates provides a functional display of bony metabolism and improves interpretation of joint pathology.6, 7 When the joint undergoes osteogenic activity, the scan shows uptake of technetium. This change makes the scan a particularly sensitive tool for earlier diagnosis than can be acquired with a standard radi0graph.s Panoramic radiography has been used routinely for screening TM disorders, but scintigraphy has not. Furthermore, interexaminer reliability in diagnosing TM joint pathology has not been determined with either technique. We therefore sought to evaluate the reliability and validity of using scintigraphy to identify adaptive changes of the TM joints. The present study had four aims: to show whether interpretation of panoramic radiographs differed among various groups of dental specialists and general practitioners; whether readings of panoramic radiographs differed from readings made of bone scans; whether technetium uptake correlated with the symptomatic side of the complaint; and whether other clinical signs and symptoms correlated with the radiologic techniques. METHODS
AND
MATERIALS
Fifteen patients (12 women and 3 men) who presented to the TMJ-Facial Pain Center at Virginia Commonwealth University School of Dentistry with signs and symptoms that could be categorized into classic syndromes of myogenous and arthrogenous TM disorders were selected for this study. The mean age of the patients was 39.6 (range, 18 to 70) years. They all had been referred to the Center, a regional clinic for the diagnosis and treatment of patients with various kinds of orofacial pain, The severity of-the
FEBRUARY
1992
VOLUME
67
NULMBER
2
BONE
Table
SCAN
AND
RADIOGRAPHIC
I[. Examiners’
Group Q.S. Q.P. Pros.
6. Dent. F (3, 16)*
TMJ
DIAGNOSIS
judgments of panoramic radiograph using bone scan as the “gold standard” True positive rate
False positive rate
True score
a,
a
Sensitivity
Specificity
0.69 0.45 0.68 0.61 1.48
0.45 0.18 0.38 0.45 1.12
0.24 0.26 0.30 0.17 0.32
0.64 0.76 0.78 0.42 0.46
0.89 1.48 0.93 0.97 0.25
0.69 0.45 0.68 0.61 1.48
0.55 0.80 0.52 0.53 1.08
O.S., Oral surgeons; O.P., oral pathologists; Pros. prosthodontists; *F, Analysis of variance; df, number in parentheses.
G. Dent. general dentists.
physical complaints was therefore likely to have been greater than that encountered in the general population. Each patient completed a health history questionnaire that included questions about the location of the pain. They signed a consent form and were examined for jaw limitation on movement, deviation of the mandible on mouth opening, tenderness of the masticatory muscles and TM joints on digital palpation, joint sounds, and tooth wear. Details of the questionnaire and the methods for examination have been previously published9 in detail. Panoramic radiographs were made of the TM joints of all patients at open and closed positions of the mouth. Three groups of dental specialists (fixed prosthodontists, oral pathologists, and oral surgeons) and one group of general dentists reviewed the panoramic radiographs. Each group consisted of five examiners. The 20 dentists were blinded to the status of the patient’s history and symptoms. Scintigraphy of all 30 TMJ was performed using 22.0 mC: of technetium-99m methyl diphosphonate given by intravenous administration. Images were obtained approximately 3 hours after injection, using a conventional gamma scintillation camera. They were reviewed by the same staff radiologist who was also blinded to the status of the patient’s history and symptoms. Signal Detection Theory (SDT)“, l1 was used to provide an estimate of the examiner’s accuracy in discriminating differences between joints, as well as in obtaining an estimate of the examiner’s response bias. SDT provides an unbiased estimate of discrimination accuracy, designated as d’, representing here the examiner’s ability to identify joints that were pathologic based on the panoramic radiographs where the bone scan was accepted as the “gold standard.” Higher values of d’ indicated greater agreement between judgments made of panoramic radiographs and the results obtained with the bone scans. Lower d’ values represented lesser agreements. The index of the examiner’s bias, designated as /?,reflected the willingness of the examiner to label a panoramic radiograph as pathologic when the bone scan was used as the “gold standard.” Higher values of p indicated less willingness to label the panoramic radiograph as pathologic, while lower /3 values indicated a relatively greater tendency toward identifying a panoramic radiograph as pathologic. Thus SDT permitted separate
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
evaluations for accuracy and response bias for the different examiners. Further distinctions between panoramic radiographs and bone scans and between the symptomatic side and bone scans were analyzed using sensitivity and specificity measures. Such measures have often been employed in epidemiologic studies of screening and diagnostic tests.i2 Sensitivity, or the true positive rate, was defined as the probability of correct identification of a case or all of the true positives divided by all those with pathology. Specificity was defined as the true negative responses divided by all responses without pathology. RESULTS Radiologic
findings
Table I summarizes the results for accuracy of judgments made about the panoramic radiographs in relation to the bone scans. In this case, a correct identification or true positive was obtained when the panoramic radiograph was judged to indicate pathology when the technetium uptake of the bone scan was used as the “gold standard.” False positives were defined as a judgment of pathology when the bone scan was within normal limits. Accuracy or agreement between judgments made by examiners was thus a function of both the true and false positive rates. The results showed that the four professional groups did not differ significantly on either true or false positive rates (Table I, Fig. 1). The four groups did not differ significantly using the true score, another index of accuracy. This index represented the true positive rate minus the false positive rate and corrected for chance success. The SDT indices of accuracy (d’) and response bias (p) are summarized for each group of examiners (Table I, Fig. 2). While the groups did not differ statistically with respect to either d’ or 0, their overall accuracy was low. This low accuracy was represented by plotting the average value for each group in the receiver operating space (Fig. 3). This space was defined by plotting the true positive rate on the y axis and the false positive rate on the x axis. Nearness of these values to the positive diagonal line indicated low discrimination ability on the part of the examiners. Put another way, the further each group’s position was from this line the greater the ability to discriminate. The posi-
247
BUSH,
=
TRUE
+
FALSE
-TRUE scoRE
1.00 0.90
0.80 0.70 0.60 P $
0.50 0.40 0.30 0.20 0.10 0.00 1
2
3
4
GROUPS Fig. 1. Comparison of true, false, and true score rates for these groups: 1, oral surgeons; 2, oral pathologists; 3, prosthodontists; and 4, general dentists.
ROC
ANALYSES groups 2
llil
d’
Ez33
ET24
beta
Fig. 2. Receiver operating characteristics (ROC) analysis showing d’ and @values for groups described in Fig. 1.
248
HARRINGTON,
AND
WARKINS
tion of points in the receiver operating space also indicated that the examiners were relatively unbiased in their judgments concerning the panoramic radiographs. That is, the pattern of points around the negative diagonal line indicated that the examiners were adopting neither a lax nor a strict set of responses. The magnitude of this low agreement between examiners’ readings of panoramic radiographs versus results for the bone scans is further indicated by the sensitivity and specificity measures (Table I, Fig. 4). In the present study, the values for sensitivity and specificity did not differ statistically between any of the professional groups. The values were equally low across all groups. A series of analyses parallel to those reported between the panoramic radiographs versus the bone scans was computed with the patient complaint as the “gold standard” and the bone scan results as the “experimental” data. This effectively asks the question, “What is the accuracy of the bone scan results in discriminating jaws with symptoms versus jaws without symptoms?” These results indicated that the accuracy of the bone scan results for identification of the symptomatic side was not significantly greater than the ability of the examiners to judge pathology on the panoramic radiographs. Both sets of results were equally inaccurate (compare Tables I and II). Clinical
findings
Tables III and IV show the signs and symptoms useful for differential diagnosis of the patients. Ten patients had then symptoms classified as mixed myogenous-arthrogenous disorders. Five (patients No. 4, 7, 8, 10, and 11) of them had greater tendencies toward myogenous involvement than arthrogenous involvement. This diagnosis was based primarily on the widespread tenderness of the masticatory and neck muscles to palpation. Two patients had negative bone scans, but the joints had reducible clicks. Three had positive bone scans; one had recently been involved in an automobile accident, one had unilateral clicking with reduction, and the third had no history of joint sounds and none at examination. Five (patients No. 1,2,3, 5, and 9) others had tendencies toward complex disk derangement. Two of these patients had closed lock conditions. Their bone scans were negative. One had localized tenderness only of the joint area; the other had a more diffuse pattern of muscular tenderness. The remaining three patients had positive bone scans; the joints clicked with reduction. The final five patients had the following diagnoses: four (patients No. 6, 13, 14, and 15) had primarily degenerative joint disease classifiable by the presence of either bilateral joint popping or coarse crepitus and little myogenous involvement. Their bone scans were positive. The last patient (No. 12) had trigeminal neuralgia and responded successfully to treatment with carbamazepine (Tegretol; Geigy Pharmaceuticals, Ardsley,
FEBRUARY
1992
VOLUME
67
?.JUMBER
2
RONE
SCAN
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RADIOGRAPHIC
TMJ
DIAGNOSIS
\ .9 ? d
\\
.8 t
\
1.28 \
\
\
1.0
0.05
.I FALSE
*
I lllll
2
.3
.4
POSITIVE
Fig. 3. Receiver operating characteristics atic side for groups described in Fig. 1.
Table
II.
.6
.7
I I
.8
.9
RATE
analysis comparing bone scan with symptom-
Comparison of bone scan using side with symptoms as the “gold standard”
True positive rate
False positive rate
True score
d’
B
Sensitivity
0.67
0.44
0.23
0.57
0.92
0.67
N.Y.), yet he bad considerable tenderness to digital palpation. Deviation ofthe mandible on opening, symptomatic side, and bone scan were not significantly related (Table III). Just two patients with myogenous involvement, one with disk derangement, and none with degenerative joint disease had mandibular deviation associated with the symptomatic side, which was unrelated to the bone scan. No significant relationship existed between the presence of tooth wear, the bone scan, and the diagnostic category (Table III). Eight patients had minimal to no wear, four of whom had arthrogenous involvement (disk or degenerative joint disease) greater than myogenous involvement. Five (patients No. 5,8,10,14, and 15) had extensive tooth wear; three had pri”marily arthrogenous involvement and two primarily had myogenous involvement. DISCUSSION The findings of the present study indicate a remarkable lack of agreement between the panoramic radiographic readings in relation to the bone scans. This lack of agree-
THE
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Specificity 0.56
ment may be caused by ambiguity of the panoramic radiograph presenting pathology of the joint, ambiguity of the bone scan findings in relation to joint changes sufficient to be apparent on the panoramic radiograph, or because of a combination of both. Clearly, these results of the bone scan findings represent a poor “gold standard” to interpret reports of articular changes. The inability to associate the symptomatic side with positive bone scan results further reflects this lack of agreement. In a random survey of 114 individuals from the general population, unequivocal technetium uptake occurred in 4 % of the TM joints.r3 Marked uptake in these few patients was associated with the presence of self-reported TM joint complaints, but TM joint complaints were present in only 50% with less marked uptake. The authors summarized the results of four other studies and concluded that an increased uptake was significant as an incidental finding of suspect TM joints. Results of other studies using different imaging techniques have shown the difficulty of relating radiographic findings to diagnosis. Interexaminer analysis of transcranial radiographs by six different clinicians showed no sig-
249
BUSH,
Table
III.
27
12 13
F F F F F F F F F F F F M
14
M
15
M
1
5
6 7 8
9 10 11
L, left; R, right;
IV.
Maximum opening (mm)
Age (Yr)
Sex
2 3 4
Table
Mandibular deviation
23 20 64 55 31
49 35 29
32 64
39 45
37 33 20
40 37 35 45
N N
70 43
43 36
N L
60
B, bilateral;
-, minimal;
B L B R L B R L B R R L B R B
N
L N N
R L N
L L
Joint noise
1
Locked
2 3 4
Locked Popping, reciprocal B Clicking B
5
Popping L, Lt B
6 7
Crepitus, coarse R Clicking R
8
Clicking L
9 10
Clicking, soft L Clicking, reciprocal R
11
N
12
N
13 14 15
Clicking, reciprocal B Popping, reciprocal B Popping, reciprocal B R, right;
scan
Tooth
B L B B B B B B L L
wear
+ + + + + +
of study to palpation
Right
Left
Auditory meatus, lateral joint surface, masseter B Masseter, temporalis B, medial pterygoid B Lateral joint surface B, masseter B, temporalis B, pterygoids B, sternocleiodmastoid B Masseter B, temporalis B, medial pterygoid B, neck, posterior B, sternocleidomastoid Lateral joint surface Masseter B, temporalis B, pterygoids B, neck, posterior B, sternocleidomastoid B Auditory meatus B, masseter B, temporalis B, pterygoids B, neck, posterior B, sternocleidomastoid B, Temporalis, pterygoids B, neck, posterior B Masseter, temporalis, pterygoids, sternocleidomastoid, Auditory meatus B, lateral joint surface B, masseter B, pterygoids, neck, posterior B, sternocleidomastoid-B
Auditory meatus, lateral joint surface Lateral joint surface
Lateral pterygoid
Auditory meatus, lateral joint surface, temporalis, medial pterygoid, neck, posterior
L, left; Lt, laterotrusion;
Masseter, pterygoids Medial pterygoid B Lateral joint surface N, normal.
nificant correlation between readability of radiographs and radiologic diagnosis of TM disorders.r4 The radiographs were read from 25 patients with a long-term history of TM disorders and from 25 individuals free of symptoms. 250
HARKINS
f, bruxism.
Tenderness
B, Bilateral;
Bone
Complaint
L L
24 28 51 46
18
Parameters
Patient No.
-
AND
Study parameters
Patient NO.
N, None;
HARRINGTON,
Among 102 patients with TM disorders, condyle position was broadly distributed at all positions for arthrosis patients.lj The position on the contralateral side in patients with unilateral symptoms was similar to the position FEBRUARY
1992
VOLUME
67
NUMBER
2
BONE
SCAN
AND
RADIOGRAPHIC
TMJ
DIAGNOSIS
SCREENINQ
ANALY3ES
groups I
2
izms
LxxJr
initial diagnosis of TM disorders. In the case of scintigraphs, their use must be weighed against the cost of this procedure. SUMMARY
0.60
Four groups of dental specialists and one group of general dentists evaluated panoramic radiographs of 30 TM joints for pathology. Comparison with bone scintigraphs of the same joints showed no statistical difference among examiners. No signs or symptoms of the patients with orofacial pain correlated with the panoramic radiographs or the scintigraphs.
0.50
REFERENCES
0.80
0.40 0.30 020 0.10
0.00 SUJSiTiVlTY
SPECIFICITY
Fig. 4. Comparison of sensitivity for groups described in Fig. 1.
and specificity values
of the main symptom side in each diagnostic category. In another study, three dentists and a medical radiologist examined a total of 150 tomograms and lateral transcranial projections of patients with TM disorders and concluded that a high percentage were impossible to interpret, and that interexaminer reliability was low even with the same technique.r6 The clinical findings further demonstrate the difficulty of using either the bone scans or the panoramic radiographs for diagnostic purposes. No important association was made with either the radiologic technique and any sign or symptom. Our findings agree with the conclusion made in a major review involving the relationship between bone scanning and metabolic bone disease that this technique is a significant research tool, but its role in clinical practice has not been established.7 This overall lack of reliability further demonstrates that panoramic radiographs and scintigraphs would be useful for diagnosis only for gross morphologic or adaptive changes in form. In the case of panoramic radiography, the statement has been made that panoramic radiography should have a limited role in dental school screening clinics.17 Also, this conclusion supports the statement made in the Report of the 1989 Committee on Scientific Investigation of the American Academy of Restorative Dentistry,ls that conventional radiologic examination is of limited use in the
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DENTISTRY
1. Griffith RH. Report of the President’s Conference on the examination, diagnosis and management of temporomandibular disorders. J Am Dent Assoe 1983;106:75-7. 2. American Academy of Pediatric Dentistry. Treatment of temporomandibular disorders in children: summary statements and recommendations. J Am Dent Assoc 1990;120:265-9. 3. Bavitz JB, Chewning LC. Malignant disease as temporomandibular joint dysfunction: review of the literature and report of case. J Am Dent Assoc 1990;120:163-6. 4. Yune HY. Roentgenologic diagnosis in chronic temporomandibular joint dysfunction syndrome. CRC Crit Rev Clin Radio1 Nucl Med 1973;1(4):161-75. 5. Raustia AM, Pyhtinen J. Morphology of the condyles and mandibular fossa as seen by computed tomography. J PROSTHET DENT 1990;63:7783. 6. Alexander JM, Fratkin MJ, Hall DL. Temporomandibular joint marking for radionuclide bone scintigraphy. J Oral Surg 1979;37:753-4. 7. Fogelman I. Bone scanning and photon absorptiometry in metabolic bone disease. Baillieres Clin Endocrinol Metab 1988;2:69-86. 8. Alexander JM. Radionuclide bone scanning in the diagnosis of lesions of the maxillofacial region. J Oral Surg 1976;34:249-56. 9. Bush FM, Whitehill JM, Martelli MF. Pain assessment in temporomandibular disorders. J Craniomandib Pratt 1989;7:137-43. 10. GreenDM, Swets JA. Signal detection theory and psychophysics. Huntington, NY: Robert E Krieger, 1974479. 11. Metz CE. Rot methodology in radiologic imaging. Invest Radio1 1986;21:720-33. 12. Mausner JS, Kramer S. Epidemiology-an introductory text. Philadelphia: WB Saunders, 1985:361. 13. Epstein DH, Graves RW, Higgins WL. Clinicai significance of increased temporomandibular joint uptake by planar bone scan. Clin Nucl Med 198?;12:705-7. 14. Wise H, Rely R, Barghi N. Radiographic diagnosis of TMJ dysfunctions: effect of readability [Abstract]. J Dent Res 1984;63:332. 15. Pullinger AG, Solberg WK, Hollender L, Guichet D. Tomographic analysis of mandibular condyle position in diagnostic subgroups of temporomandibular disorders. J PROSTHET DENT 1986;55:723-9. 16. Van Den Berghe LI, De Boever J, Veys R, Allewaert J. Inter-examiner reliability of radiographic diagnosis in TMJ-dysfunction [Abstract]. J Dent Res 1986;65:821. 17. Kantor ML, Slome EA. Efficacy of panoramic radiography in dental diagnosis and treatment planning. J Dent Res 1989;68:810-2. 18. Phillips RW, Jendresen MD, Klooster J, McNeil C, Preston JO, Schalihorn RG. Report of the Committee on Scientific Invest.igation of the American Academy of Restorative Dentistry. J PROSTHET DENT 1989;62:70-109.
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251
