ARTICLE IN PRESS
YBJOM-4158; No. of Pages 6
Available online at www.sciencedirect.com
British Journal of Oral and Maxillofacial Surgery xxx (2014) xxx–xxx
Value of cone-beam computed tomography in the process of diagnosis and management of disorders of the temporomandibular joint E.W.J. de Boer a,∗ , P.U. Dijkstra a,b , B. Stegenga a , L.G.M. de Bont a , F.K.L. Spijkervet a a
Department of Oral and Maxillofacial Surgery, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands Department of Rehabilitation Medicine, Centre for Rehabilitation, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
b
Accepted 9 December 2013
Abstract The objective of this study was to assess the value of cone-beam computed tomographic (CT) images in the primary diagnosis and management of 128 outpatients with disorders of the temporomandibular joint (TMJ). Before a diagnosis was made and treatment planned, the history was taken, physical examination made, and the orthopantomogram studied. After assessment of the cone-beam CT, the oral and maxillofacial surgeon (specialist or resident) was allowed to revise the provisional primary diagnosis and management. The degree of certainty was rated by the clinician before and after the cone-beam CT had been assessed. The primary diagnosis was changed in 32 patients (25%), additional diagnostic procedures were changed in 57 (45%), and the treatment was changed in 15 (12%) (in 4 the treatment was changed to a (minimally) invasive procedure). A total of 74 patients (58%) had their diagnosis and management changed after the cone-beam CT had been assessed. Changes in diagnosis and management were clinically relevant in 9/32 and 9/61 patients, respectively. The clinician’s certainty about the primary diagnosis increased after the cone-beam CT had been assessed in 57 patients. Logistic regression analysis showed that the odds in favour of changes in primary diagnosis and management increased when limited mandibular function was a primary symptom, the patient was taking medication for pain, and the articular eminence could not be assessed on OPT. Assessment of cone-beam CT led to changes in primary diagnosis and management in more than half the patients with disorders of the TMJ. © 2013 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Temporomandibular joint; Cone beam computed tomography; Decision making; Diagnosis; Disorders, Temporomandibular joint
Introduction The diagnostic process in patients with disorders of the temporomandibular joint (TMJ) consists of taking the history, making a physical examination, and using additional diagnostic procedures including imaging of the TMJ.1 After history and physical examination a (differential) diagnosis is made. To confirm or refute this, further procedures are needed as ∗ Corresponding author at: Department of Oral and Maxillofacial Surgery, UMC Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands. Tel.: +31 0503613840; fax: +31 0503611136. E-mail address: [email protected] (E.W.J. de Boer).
internal derangements of the TMJ cannot be diagnosed reliably on clinical examination alone.2 A panoramic radiograph (orthopantomogram (OPT)) is often taken to assess the general condition of the teeth and structures of the maxilla and the mandible. To obtain more detailed information about the bony structures of the TMJ, other radiographs including conventional transpharyngeal radiographs or multidetector computed tomographic (CT) scans can be taken,3 and magnetic resonance images (MRI) will give information about the articular disc and the surrounding soft tissues.4 A relatively new imaging technique is cone-beam CT, and this enables 3-dimensional imaging of bony structures of the skull, including the mandible and the TMJ.5 An advantage
0266-4356/$ – see front matter © 2013 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.bjoms.2013.12.007
Please cite this article in press as: de Boer EWJ, et al. Value of cone-beam computed tomography in the process of diagnosis and management of disorders of the temporomandibular joint. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2013.12.007
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of cone-beam CT over multidetector CT is that it requires a lower dose of radiation (>35% in medium field of view).6 In addition, with sagittal cross-sectional tomography, all components of the TMJ can be examined, unlike with panoramic and sagittal (lateral) radiography.7 The diagnostic accuracy of cone-beam CT in detecting condylar osseous abnormalities (0.9) was reported to be similar to that of multidetector CT (0.86),8 while the sensitivity of cone-beam CT in the detection of these abnormalities was 0.8 and for CT 0.7. Specificity was identical for cone-beam CT and multidetector CT (1.0).8 Cone-beam CT provides accurate and reliable linear measurements of the dimensions of the mandible and the TMJ because of its nearly 1:1 reconstruction.9 The diagnostic accuracy of cone-beam CT in detecting cortical erosion of the mandibular condyle is greater (0.77–0.95) than that of either OPT (0.55–0.64) or linear tomography (0.58).10 Its diagnostic properties in assessing bony conditions, therefore, seem to be similar to, or better than, existing imaging techniques. Until now little has been known about the role of cone-beam CT in clinical decision-making in diagnosis or management of disorders of the TMJ. This information is relevant to prevent patients from being unnecessarily exposed to radiation and to optimise diagnostic accuracy. The aims of this study were to assess the value of conebeam CT images in making clinical decisions about the primary diagnosis and management of patients with disorders of the TMJ after history, physical examination, and OPT had been considered; to assess the clinical relevance of any changes made in the primary diagnosis and management; and to work out how they affected the clinician’s certainty about the initial primary diagnosis.
Patients and methods This study was approved by the medical ethics committee of the University Medical Centre, Groningen, the Netherlands (METc 2010/019). Patients Consecutive eligible patients from the outpatient clinic of the department of Oral and Maxillofacial Surgery at the University Medical Centre of Groningen, the Netherlands, were recruited between April 2010 and July 2011. Patients were eligible if they had been referred by a dentist, general practitioner, or medical specialist with complaints related to the TMJ or muscles of mastication. Inclusion criteria were: age 18 years or over with movement-related pain in the area of TMJ or muscles of mastication; or limitation of movement or function of the TMJ; or had joint sounds, or a combination of these complaints. Patients were excluded if it became clear during history-taking and physical examination that they had something other than a disorder of the TMJ. For each patient 2 radiographs were taken: a full OPT (dose 0.01 mSv including maxilla and mandible (OP200D, Oldelft Benelux)), and
a cone-beam CT (dose 0.09–0.13 mSv; exposure time: 8.9 s, with 0.8 voxels (i-CAT, Imaging Sciences International)). Procedure A standard protocol was followed that reflected the diagnostic procedures for patients newly referred to our department. Patients were examined by 1 of 3 oral maxillofacial surgeons (OMFS) who had specialised for over 20 years in the diagnosis and treatment of patients with disorders of the TMJ (specialist), or one of 13 residents (who were free to consult a supervisor at any time). All clinicians, including residents, had been given standard training in the interpretation of OPT and cone-beam CT images and were familiar with the protocol before the study started. First, history of signs and symptoms, findings of physical examination, primary (differential) diagnosis, additional diagnostic procedures and treatment plan were recorded (Appendix – online only). The findings from the OPT were then recorded. The (differential) diagnosis, additional diagnostic procedures, and treatment were then reconsidered and recorded. The clinician then rated his certainty about the primary diagnosis at this stage as a percentage (0 = not certain, 100 = absolutely certain). Next, cone-beam CT (screen resolution: 1600 × 1000) was shown to the clinician and assessed using the same criteria as had been used for the OPT (Appendix – online only). Cone-beam CT images of the TMJ were viewed in sagittal, coronal, and transverse planes (Fig. 1). The findings were recorded, and (the differential) diagnosis, certainty about the diagnosis, additional diagnostic procedures, and the treatment plan were reconsidered and recorded. Finally, the clinician rated the clinical importance of the changes in primary diagnosis and management as a result of the information on cone-beam CT images on a 4point scale (very important, important, not really important, and not important). The final primary diagnosis was classified as arthrogenous, myogenous, a combination of both, or other. Additional diagnostic procedures were classified as: none, specific radiographs of the TMJ, minimally invasive diagnostic procedures (such as injection of an analgesic), or other diagnostic imaging procedures (such as MRI, or positron emission tomographic (PET) scan). Treatment was classified into nonsurgical, minimally invasive, invasive, other treatment, or insufficient data to decide on treatment (Appendix – online only). The primary outcome measures of this study were: the number of patients for whom primary diagnosis, additional diagnostic procedures, or treatment, had been changed after assessment of the cone-beam CT images, and the number of patients in whom one or more changes were required. Secondary outcome measures were the clinical importance of the changes in the primary diagnosis and management, and changes in the clinician’s certainty about the primary diagnosis.
Please cite this article in press as: de Boer EWJ, et al. Value of cone-beam computed tomography in the process of diagnosis and management of disorders of the temporomandibular joint. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2013.12.007
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Fig. 1. Orthopantomogram (OPT) and cone-beam computed tomographic (CT) images of the right temporomandibular joint (TMJ) in 2 planes (A. coronal, B and C sagittal) of a 54-year-old man. His clinical symptoms were pain, limitation of function, maximal mouth opening 34 mm limited by pain, crepitations, painful right TMJ on palpation, and pain on distraction of the right TMJ. The radiographic finding on OPT was that the right TMJ was not assessable because of composite shadowing. The radiographic findings on cone-beam CT were: (A) surface erosion and subchondral cyst of the right TMJ, (B) subchondral sclerosis and surface erosions, and (C) surface erosions (as a result of former subchondral cysts). The diagnosis was osteoarthrosis of the right TMJ.
Statistical analyses Before the study we hypothesised that the clinician would change primary diagnosis, diagnostic procedures, or treatment plan after the cone-beam CT in 10% of patients. To estimate this with a precision of 5%, a sample of 134 patients was needed. Characteristics of patients, their history and physical examination, and findings on OPT were explored for the univariate relations between the changes using non-parametric and parametric analyses, as appropriate. Backward logistic regression analysis was used to assess the significance of differences between factors that were associated with these changes. Separate calculations were made for changes in primary diagnosis, additional diagnostic procedures, and treatment plan, and for changes in any of these items. All analyses were made with the help of SPSS (version 20, IBM Corp, Amonk, NY, USA).
Results A total of 131 patients agreed to participate. Three patients who did not have disorders of the TMJ were excluded, resulting in 128 participants (37 men and 91 women, mean (SD) age 41 (15) years) (Table 1). Thirty-four patients were seen by one
of the OMFS specialists, the others by residents. Residents asked advice from a supervisor on 3 occasions. Clinicians made changes in primary diagnosis, additional diagnostic procedures, treatment, or a combination of these, after assessment of the cone beam CT (Fig. 2) in 74 cases (58%, 95%CI 49–66) of which specialists made changes in 27. Changes were made after analysing cone-beam CT in primary diagnosis in 32 patients (25%). In 63% (n = 20) of these patients the changes were within the same diagnostic classification – for example, arthritis changed to arthrosis, while in 12 (38%) it was changed to a different diagnosis. Before cone-beam CT was assessed in 53 patients (42%) TMJ-specific radiographs were requested (2 of which were missing). Assessment of the scans led to requests for minimally invasive diagnostic procedures in 7 patients, referral to a specialist in 3, and diagnostic procedures at another department in one. In 39 patients no additional diagnostic procedures were requested. In two patients in whom no additional diagnostic procedures had been requested before cone-beam CT had been requested, assessment of cone-beam CT led to referral to a TMJ specialist. Before the cone-beam CT had been assessed, minimally invasive treatment had been provisionally suggested for 7 patients, and invasive treatment for 4. In 14 patients we had insufficient data to suggest treatment. After the cone-beam CT had been assessed, minimally invasive treatment was
Please cite this article in press as: de Boer EWJ, et al. Value of cone-beam computed tomography in the process of diagnosis and management of disorders of the temporomandibular joint. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2013.12.007
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Table 1 Characteristics of participants, symptoms, and main findings on physical examination (n = 128). Data are number (%) of patients except where otherwise stated. Characteristics Female Mean (SD) age (years) Consultation by OMFS resident (n = 13) Consultation by OMFS TMJ specialist (n = 3) Median (IQR) duration of complaints (months) History Primary symptomsa Pain Limitation of function Limitation of movement Joint sounds Additional symptoms Joint sounds Jaw stiffness Limitation in mandibular function Limitation in mandibular movement Clenching/grinding Medication For pain Other medication Findings on physical examination Restricted translation Pain in TMJ (on palpation) Pain in TMJ (on distraction) Pain in TMJ(on axial pressure) Clicking Crepitation Painful masseter muscle Painful temporalis muscle
91 (71) 41 (15) 94 (73) 34 (27) 14 (6–48)
84 (66) 26 (20) 32 (25) 33 (26) 95 (74) 31 (24) 68 (53) 59 (46) 39 (31) 40 (31) 56 (44) 32 (25) 27 (21) 32 (25) 23 (18) 61 (48) 19 (15) 79 (62) 56 (46)
a Some patients reported more than one symptom, so the total percentage may exceed 100.
Fig. 2. Changes that occur during primary diagnosis, diagnostic procedures, and treatment after analysis of cone-beam computed tomography in 128 patients. The size of the circles does not indicate frequency.
suggested for 10 patients, and invasive treatment for 5. In 12 patients there was insufficient data for treatment (Appendix, Tables 1A–3A, online only). In 9/32 patients (28%) changes in the primary diagnosis were judged to be clinically relevant. Sixty-one patients had their management changed, which was judged to be clinically relevant in 9 (15%) (in 3 we had insufficient data). In 57 patients (46%), certainty about the primary diagnosis was increased after assessment of the cone-beam CT, in 62 patients (51%) it did not change, and in 3 (3%) the degree of certainty was reduced. Several findings in the history and physical examination were significantly related to changes in the primary diagnosis, additional diagnostic procedures, and treatment (Appendix, Table 4A, online only). The odds of a change in primary diagnosis were increased by the presence of limitation of mandibular function as a primary symptom and pain in the TMJ on palpation (Table 2). The presence of clicking reduced the odds of a change in the primary diagnosis. The presence of limitation of mandibular function and movement, and the fact that it was not possible to assess all aspects of the OPT, increased the odds of a change in additional diagnostic procedures. Stiffness of the jaw and taking medication other than for pain increased the odds of a change in treatment. The presence of limitation of mandibular movement as a primary symptom, limitation of mandibular function, medication for pain, and the fact that the articular eminence could not be assessed on OPT, increased the odds of changes in primary diagnosis and management.
Discussion Cone-beam CT has a considerable impact on clinical decision-making in patients with disorders of the TMJ. After the cone-beam CT had been assessed, the primary diagnosis, additional diagnostic procedures, treatment, or a combination of these were changed in more than half the patients, and the clinician’s certainty about the primary diagnosis increased in 57/122 patients (46%). Changes made in the differential diagnosis and management after the cone-beam CT had been assessed were judged to be clinically relevant by the clinician in 9/32 (28%) and in 9/61 patients (15%), respectively. To change a diagnosis of an arthrogenous condition into an arthrogenous and myogenous one may seem contradictory. However, this happened when there were no degenerative findings on cone-beam CT, and the surgeon felt that the arthrogenous and myogenous symptoms were contributing equally to the diagnosis. In contrast to our hypothesis, we found more changes in primary diagnosis and management: 74 (58%) (95%CI 49–66) compared with 13 (10%) (95%CI 6–16). A retrospective study found that analysing tomograms of TMJ led to changes in diagnosis in 28/116 patients (24%) and management in 20/116 (17%),11 while another retrospective study reported that the study of frontal and lateral tomograms of the TMJ resulted in changes in diagnosis in 365/555
Please cite this article in press as: de Boer EWJ, et al. Value of cone-beam computed tomography in the process of diagnosis and management of disorders of the temporomandibular joint. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2013.12.007
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Table 2 Logistic regression to predict changes in primary diagnosis, diagnostic procedures, and treatment plan after analysing cone-beam computed tomographic scans (CBCT). Predictors of outcome
β (SE)
Odds ratio (95% CI)
p-Value
Changes in primary diagnosis Constant Limitation in mandibular movement, as primary symptomH Pain in TMJ on palpationPE ClickingPE
−1.97 (0.36) 0.84 (0.47) 1.24 (0.48) −0.76 (0.44)
2.33 (0.94–5.78) 3.47 (1.36–8.88) 0.47 (0.20–1.11)
YBJOM-4158; No. of Pages 6
Available online at www.sciencedirect.com
British Journal of Oral and Maxillofacial Surgery xxx (2014) xxx–xxx
Value of cone-beam computed tomography in the process of diagnosis and management of disorders of the temporomandibular joint E.W.J. de Boer a,∗ , P.U. Dijkstra a,b , B. Stegenga a , L.G.M. de Bont a , F.K.L. Spijkervet a a
Department of Oral and Maxillofacial Surgery, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands Department of Rehabilitation Medicine, Centre for Rehabilitation, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
b
Accepted 9 December 2013
Abstract The objective of this study was to assess the value of cone-beam computed tomographic (CT) images in the primary diagnosis and management of 128 outpatients with disorders of the temporomandibular joint (TMJ). Before a diagnosis was made and treatment planned, the history was taken, physical examination made, and the orthopantomogram studied. After assessment of the cone-beam CT, the oral and maxillofacial surgeon (specialist or resident) was allowed to revise the provisional primary diagnosis and management. The degree of certainty was rated by the clinician before and after the cone-beam CT had been assessed. The primary diagnosis was changed in 32 patients (25%), additional diagnostic procedures were changed in 57 (45%), and the treatment was changed in 15 (12%) (in 4 the treatment was changed to a (minimally) invasive procedure). A total of 74 patients (58%) had their diagnosis and management changed after the cone-beam CT had been assessed. Changes in diagnosis and management were clinically relevant in 9/32 and 9/61 patients, respectively. The clinician’s certainty about the primary diagnosis increased after the cone-beam CT had been assessed in 57 patients. Logistic regression analysis showed that the odds in favour of changes in primary diagnosis and management increased when limited mandibular function was a primary symptom, the patient was taking medication for pain, and the articular eminence could not be assessed on OPT. Assessment of cone-beam CT led to changes in primary diagnosis and management in more than half the patients with disorders of the TMJ. © 2013 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Temporomandibular joint; Cone beam computed tomography; Decision making; Diagnosis; Disorders, Temporomandibular joint
Introduction The diagnostic process in patients with disorders of the temporomandibular joint (TMJ) consists of taking the history, making a physical examination, and using additional diagnostic procedures including imaging of the TMJ.1 After history and physical examination a (differential) diagnosis is made. To confirm or refute this, further procedures are needed as ∗ Corresponding author at: Department of Oral and Maxillofacial Surgery, UMC Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands. Tel.: +31 0503613840; fax: +31 0503611136. E-mail address: [email protected] (E.W.J. de Boer).
internal derangements of the TMJ cannot be diagnosed reliably on clinical examination alone.2 A panoramic radiograph (orthopantomogram (OPT)) is often taken to assess the general condition of the teeth and structures of the maxilla and the mandible. To obtain more detailed information about the bony structures of the TMJ, other radiographs including conventional transpharyngeal radiographs or multidetector computed tomographic (CT) scans can be taken,3 and magnetic resonance images (MRI) will give information about the articular disc and the surrounding soft tissues.4 A relatively new imaging technique is cone-beam CT, and this enables 3-dimensional imaging of bony structures of the skull, including the mandible and the TMJ.5 An advantage
0266-4356/$ – see front matter © 2013 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.bjoms.2013.12.007
Please cite this article in press as: de Boer EWJ, et al. Value of cone-beam computed tomography in the process of diagnosis and management of disorders of the temporomandibular joint. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2013.12.007
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of cone-beam CT over multidetector CT is that it requires a lower dose of radiation (>35% in medium field of view).6 In addition, with sagittal cross-sectional tomography, all components of the TMJ can be examined, unlike with panoramic and sagittal (lateral) radiography.7 The diagnostic accuracy of cone-beam CT in detecting condylar osseous abnormalities (0.9) was reported to be similar to that of multidetector CT (0.86),8 while the sensitivity of cone-beam CT in the detection of these abnormalities was 0.8 and for CT 0.7. Specificity was identical for cone-beam CT and multidetector CT (1.0).8 Cone-beam CT provides accurate and reliable linear measurements of the dimensions of the mandible and the TMJ because of its nearly 1:1 reconstruction.9 The diagnostic accuracy of cone-beam CT in detecting cortical erosion of the mandibular condyle is greater (0.77–0.95) than that of either OPT (0.55–0.64) or linear tomography (0.58).10 Its diagnostic properties in assessing bony conditions, therefore, seem to be similar to, or better than, existing imaging techniques. Until now little has been known about the role of cone-beam CT in clinical decision-making in diagnosis or management of disorders of the TMJ. This information is relevant to prevent patients from being unnecessarily exposed to radiation and to optimise diagnostic accuracy. The aims of this study were to assess the value of conebeam CT images in making clinical decisions about the primary diagnosis and management of patients with disorders of the TMJ after history, physical examination, and OPT had been considered; to assess the clinical relevance of any changes made in the primary diagnosis and management; and to work out how they affected the clinician’s certainty about the initial primary diagnosis.
Patients and methods This study was approved by the medical ethics committee of the University Medical Centre, Groningen, the Netherlands (METc 2010/019). Patients Consecutive eligible patients from the outpatient clinic of the department of Oral and Maxillofacial Surgery at the University Medical Centre of Groningen, the Netherlands, were recruited between April 2010 and July 2011. Patients were eligible if they had been referred by a dentist, general practitioner, or medical specialist with complaints related to the TMJ or muscles of mastication. Inclusion criteria were: age 18 years or over with movement-related pain in the area of TMJ or muscles of mastication; or limitation of movement or function of the TMJ; or had joint sounds, or a combination of these complaints. Patients were excluded if it became clear during history-taking and physical examination that they had something other than a disorder of the TMJ. For each patient 2 radiographs were taken: a full OPT (dose 0.01 mSv including maxilla and mandible (OP200D, Oldelft Benelux)), and
a cone-beam CT (dose 0.09–0.13 mSv; exposure time: 8.9 s, with 0.8 voxels (i-CAT, Imaging Sciences International)). Procedure A standard protocol was followed that reflected the diagnostic procedures for patients newly referred to our department. Patients were examined by 1 of 3 oral maxillofacial surgeons (OMFS) who had specialised for over 20 years in the diagnosis and treatment of patients with disorders of the TMJ (specialist), or one of 13 residents (who were free to consult a supervisor at any time). All clinicians, including residents, had been given standard training in the interpretation of OPT and cone-beam CT images and were familiar with the protocol before the study started. First, history of signs and symptoms, findings of physical examination, primary (differential) diagnosis, additional diagnostic procedures and treatment plan were recorded (Appendix – online only). The findings from the OPT were then recorded. The (differential) diagnosis, additional diagnostic procedures, and treatment were then reconsidered and recorded. The clinician then rated his certainty about the primary diagnosis at this stage as a percentage (0 = not certain, 100 = absolutely certain). Next, cone-beam CT (screen resolution: 1600 × 1000) was shown to the clinician and assessed using the same criteria as had been used for the OPT (Appendix – online only). Cone-beam CT images of the TMJ were viewed in sagittal, coronal, and transverse planes (Fig. 1). The findings were recorded, and (the differential) diagnosis, certainty about the diagnosis, additional diagnostic procedures, and the treatment plan were reconsidered and recorded. Finally, the clinician rated the clinical importance of the changes in primary diagnosis and management as a result of the information on cone-beam CT images on a 4point scale (very important, important, not really important, and not important). The final primary diagnosis was classified as arthrogenous, myogenous, a combination of both, or other. Additional diagnostic procedures were classified as: none, specific radiographs of the TMJ, minimally invasive diagnostic procedures (such as injection of an analgesic), or other diagnostic imaging procedures (such as MRI, or positron emission tomographic (PET) scan). Treatment was classified into nonsurgical, minimally invasive, invasive, other treatment, or insufficient data to decide on treatment (Appendix – online only). The primary outcome measures of this study were: the number of patients for whom primary diagnosis, additional diagnostic procedures, or treatment, had been changed after assessment of the cone-beam CT images, and the number of patients in whom one or more changes were required. Secondary outcome measures were the clinical importance of the changes in the primary diagnosis and management, and changes in the clinician’s certainty about the primary diagnosis.
Please cite this article in press as: de Boer EWJ, et al. Value of cone-beam computed tomography in the process of diagnosis and management of disorders of the temporomandibular joint. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2013.12.007
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Fig. 1. Orthopantomogram (OPT) and cone-beam computed tomographic (CT) images of the right temporomandibular joint (TMJ) in 2 planes (A. coronal, B and C sagittal) of a 54-year-old man. His clinical symptoms were pain, limitation of function, maximal mouth opening 34 mm limited by pain, crepitations, painful right TMJ on palpation, and pain on distraction of the right TMJ. The radiographic finding on OPT was that the right TMJ was not assessable because of composite shadowing. The radiographic findings on cone-beam CT were: (A) surface erosion and subchondral cyst of the right TMJ, (B) subchondral sclerosis and surface erosions, and (C) surface erosions (as a result of former subchondral cysts). The diagnosis was osteoarthrosis of the right TMJ.
Statistical analyses Before the study we hypothesised that the clinician would change primary diagnosis, diagnostic procedures, or treatment plan after the cone-beam CT in 10% of patients. To estimate this with a precision of 5%, a sample of 134 patients was needed. Characteristics of patients, their history and physical examination, and findings on OPT were explored for the univariate relations between the changes using non-parametric and parametric analyses, as appropriate. Backward logistic regression analysis was used to assess the significance of differences between factors that were associated with these changes. Separate calculations were made for changes in primary diagnosis, additional diagnostic procedures, and treatment plan, and for changes in any of these items. All analyses were made with the help of SPSS (version 20, IBM Corp, Amonk, NY, USA).
Results A total of 131 patients agreed to participate. Three patients who did not have disorders of the TMJ were excluded, resulting in 128 participants (37 men and 91 women, mean (SD) age 41 (15) years) (Table 1). Thirty-four patients were seen by one
of the OMFS specialists, the others by residents. Residents asked advice from a supervisor on 3 occasions. Clinicians made changes in primary diagnosis, additional diagnostic procedures, treatment, or a combination of these, after assessment of the cone beam CT (Fig. 2) in 74 cases (58%, 95%CI 49–66) of which specialists made changes in 27. Changes were made after analysing cone-beam CT in primary diagnosis in 32 patients (25%). In 63% (n = 20) of these patients the changes were within the same diagnostic classification – for example, arthritis changed to arthrosis, while in 12 (38%) it was changed to a different diagnosis. Before cone-beam CT was assessed in 53 patients (42%) TMJ-specific radiographs were requested (2 of which were missing). Assessment of the scans led to requests for minimally invasive diagnostic procedures in 7 patients, referral to a specialist in 3, and diagnostic procedures at another department in one. In 39 patients no additional diagnostic procedures were requested. In two patients in whom no additional diagnostic procedures had been requested before cone-beam CT had been requested, assessment of cone-beam CT led to referral to a TMJ specialist. Before the cone-beam CT had been assessed, minimally invasive treatment had been provisionally suggested for 7 patients, and invasive treatment for 4. In 14 patients we had insufficient data to suggest treatment. After the cone-beam CT had been assessed, minimally invasive treatment was
Please cite this article in press as: de Boer EWJ, et al. Value of cone-beam computed tomography in the process of diagnosis and management of disorders of the temporomandibular joint. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2013.12.007
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Table 1 Characteristics of participants, symptoms, and main findings on physical examination (n = 128). Data are number (%) of patients except where otherwise stated. Characteristics Female Mean (SD) age (years) Consultation by OMFS resident (n = 13) Consultation by OMFS TMJ specialist (n = 3) Median (IQR) duration of complaints (months) History Primary symptomsa Pain Limitation of function Limitation of movement Joint sounds Additional symptoms Joint sounds Jaw stiffness Limitation in mandibular function Limitation in mandibular movement Clenching/grinding Medication For pain Other medication Findings on physical examination Restricted translation Pain in TMJ (on palpation) Pain in TMJ (on distraction) Pain in TMJ(on axial pressure) Clicking Crepitation Painful masseter muscle Painful temporalis muscle
91 (71) 41 (15) 94 (73) 34 (27) 14 (6–48)
84 (66) 26 (20) 32 (25) 33 (26) 95 (74) 31 (24) 68 (53) 59 (46) 39 (31) 40 (31) 56 (44) 32 (25) 27 (21) 32 (25) 23 (18) 61 (48) 19 (15) 79 (62) 56 (46)
a Some patients reported more than one symptom, so the total percentage may exceed 100.
Fig. 2. Changes that occur during primary diagnosis, diagnostic procedures, and treatment after analysis of cone-beam computed tomography in 128 patients. The size of the circles does not indicate frequency.
suggested for 10 patients, and invasive treatment for 5. In 12 patients there was insufficient data for treatment (Appendix, Tables 1A–3A, online only). In 9/32 patients (28%) changes in the primary diagnosis were judged to be clinically relevant. Sixty-one patients had their management changed, which was judged to be clinically relevant in 9 (15%) (in 3 we had insufficient data). In 57 patients (46%), certainty about the primary diagnosis was increased after assessment of the cone-beam CT, in 62 patients (51%) it did not change, and in 3 (3%) the degree of certainty was reduced. Several findings in the history and physical examination were significantly related to changes in the primary diagnosis, additional diagnostic procedures, and treatment (Appendix, Table 4A, online only). The odds of a change in primary diagnosis were increased by the presence of limitation of mandibular function as a primary symptom and pain in the TMJ on palpation (Table 2). The presence of clicking reduced the odds of a change in the primary diagnosis. The presence of limitation of mandibular function and movement, and the fact that it was not possible to assess all aspects of the OPT, increased the odds of a change in additional diagnostic procedures. Stiffness of the jaw and taking medication other than for pain increased the odds of a change in treatment. The presence of limitation of mandibular movement as a primary symptom, limitation of mandibular function, medication for pain, and the fact that the articular eminence could not be assessed on OPT, increased the odds of changes in primary diagnosis and management.
Discussion Cone-beam CT has a considerable impact on clinical decision-making in patients with disorders of the TMJ. After the cone-beam CT had been assessed, the primary diagnosis, additional diagnostic procedures, treatment, or a combination of these were changed in more than half the patients, and the clinician’s certainty about the primary diagnosis increased in 57/122 patients (46%). Changes made in the differential diagnosis and management after the cone-beam CT had been assessed were judged to be clinically relevant by the clinician in 9/32 (28%) and in 9/61 patients (15%), respectively. To change a diagnosis of an arthrogenous condition into an arthrogenous and myogenous one may seem contradictory. However, this happened when there were no degenerative findings on cone-beam CT, and the surgeon felt that the arthrogenous and myogenous symptoms were contributing equally to the diagnosis. In contrast to our hypothesis, we found more changes in primary diagnosis and management: 74 (58%) (95%CI 49–66) compared with 13 (10%) (95%CI 6–16). A retrospective study found that analysing tomograms of TMJ led to changes in diagnosis in 28/116 patients (24%) and management in 20/116 (17%),11 while another retrospective study reported that the study of frontal and lateral tomograms of the TMJ resulted in changes in diagnosis in 365/555
Please cite this article in press as: de Boer EWJ, et al. Value of cone-beam computed tomography in the process of diagnosis and management of disorders of the temporomandibular joint. Br J Oral Maxillofac Surg (2014), http://dx.doi.org/10.1016/j.bjoms.2013.12.007
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YBJOM-4158; No. of Pages 6
E.W.J. de Boer et al. / British Journal of Oral and Maxillofacial Surgery xxx (2014) xxx–xxx
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Table 2 Logistic regression to predict changes in primary diagnosis, diagnostic procedures, and treatment plan after analysing cone-beam computed tomographic scans (CBCT). Predictors of outcome
β (SE)
Odds ratio (95% CI)
p-Value
Changes in primary diagnosis Constant Limitation in mandibular movement, as primary symptomH Pain in TMJ on palpationPE ClickingPE
−1.97 (0.36) 0.84 (0.47) 1.24 (0.48) −0.76 (0.44)
2.33 (0.94–5.78) 3.47 (1.36–8.88) 0.47 (0.20–1.11)
