The ESTMJS (European Society of Temporomandibular Joint Surgeons) Consensus and Evidence-Based Recommendations on Management of Condylar Dislocation.

Although condylar dislocation is not uncommon, terminology, diagnostics, and treatment concepts vary considerably worldwide. This study aims to present a consensus recommendation based on systematically reviewed literature and approved by the European Society of TMJ Surgeons (ESTMJS). Based on the template of the evidence-based German guideline (register # 007-063) the ESTMJS members voted on 30 draft recommendations regarding terminology, diagnostics, and treatment initially via a blinded modified Delphi procedure. After unblinding, a discussion and voting followed, using a structured consensus process in 2019. An independent moderator documented and evaluated voting results and alterations from the original draft. Although the results of the preliminary voting were very heterogenous and differed significantly from the German S3 guideline (p < 0.0005), a strong consensus was achieved in the final voting on terminology, diagnostics, and treatment. In this voting, multiple alterations, including adding and discarding recommendations, led to 24 final recommendations on assessment and management of TMJ dislocation. To our knowledge, the ESTMJS condylar dislocation recommendations are the first both evidence and consensus-based international recommendations in the field of TMJ surgery. We recommend they form the basis for clinical practice guidelines for the management of dislocations of the mandibular condyle.

Evaluation of temporomandibular function after high partial condylectomy because of unilateral condylar hyperactivity.

PURPOSE: The purpose of this study was to assess temporomandibular function after condylectomy because of unilateral condylar hyperactivity (UCH) by means of standardized diagnostic criteria. The results were compared with those obtained in a control group. PATIENTS AND METHODS: In this study, 33 patients with UCH who underwent condylectomy and 31 controls matched for age and gender filled out a history questionnaire and underwent a clinical examination as part of the research diagnostic criteria for temporomandibular disorders. Data analysis was performed by use of the Fisher exact test for 2-by-2 tables. RESULTS: Patients and controls did not differ significantly regarding myofacial pain (P = .131), disc displacement (P = .516), and depression (P = .34). The groups differed significantly concerning arthralgia, osteoarthritis, and osteoarthrosis (P = .003), as well as pain with low disability (P = .022). CONCLUSIONS: In patients with UCH who underwent condylectomy because of progressive mandibular asymmetry, more joint-related temporomandibular problems as well as more postoperative pain developed when compared with age- and gender-matched controls. However, these problems did not lead to more severe disabilities in daily life.

Unilateral condylar hyperactivity: a histopathologic analysis of 47 patients.

PURPOSE: To perform a histopathologic analysis of condyles that were resected because of unilateral condylar hyperactivity and compare the results of the bone scan with the histopathologic findings. PATIENTS AND METHODS: A total of 47 resected condyles were histopathologically examined. In 29 cases, a single photon emission computed tomography (SPECT) bone scan was available. For all condylar specimens, a standardized histologic scoring system was used to assess the number of cartilage islands and the thickness of the cartilage layer. The SPECT scans were analyzed by calculating the difference in bone activity between the hyperactive and contralateral condyles. RESULTS: The number of cartilage islands was highly variable, ranging from almost absent in 37% of the patients to abundant in 35%. Furthermore, the relative thickness of the cartilage layer exhibited considerable variation, from less than one quarter of the total thickness of the condylar articular layer in 22% of the patients to one half of the total thickness in 35%. We found no significant relationship between the number of cartilage islands and bone activity using SPECT (P = .11) or between the relative thickness of the cartilage layer and bone activity using SPECT (P = .82). CONCLUSIONS: Unilateral condylar bone growth can occur without large numbers of cartilage islands and without abundant cartilage formation. The bone activity measured by bone scintigraphy was not related to the histologic results. The histopathologic findings of resected condyles in unilateral condylar hyperactivity cannot, therefore, be used as a reference standard. Nevertheless, histopathologic examination should always be performed to rule out other diseases.

No signs of metabolic hyperactivity in patients with unilateral condylar hyperactivity: an in vivo positron emission tomography study.

PURPOSE: The purpose of this study was to assess bone growth and blood flow in the condylar region in patients with unilateral condylar hyperactivity (UCH) by use of positron emission tomography (PET). PATIENTS AND METHODS: This prospective study included 7 patients with UCH and a control group of 6 volunteers. In addition to normal clinical investigations, labeled fluoride ((18)F(-)) and oxygen 15-labeled water (H(2)(15)O) PET scans were performed. RESULTS: In control subjects the net rate of fluoride influx, representing bone metabolism, was similar for left and right condylar sides. Interestingly, this was not significantly different from the affected condyles in UCH patients. Rather, the net rate of fluoride influx on the contralateral side of UCH patients was reduced significantly compared with the affected side (P= .02) and control subjects (P= .004). The mean blood flow on the left and right condylar sides in control subjects was not significantly different. The same was true for the hyperactive and contralateral condyles of UCH patients. Blood flow in the condylar region in UCH patients was similar to that in the control group. CONCLUSIONS: There was no evidence of an abnormally high rate of bone growth in the affected condylar region in UCH patients. Instead, the rate of bone growth appeared to be reduced in the contralateral condylar region. These PET results are in contrast to the characteristic clinical picture of UCH patients and suggest the possibility of subgroups in patients with a mandibular asymmetry caused by UCH. Furthermore, no evidence of hypervascularization of the condylar region in UCH patients was found.

Quantification of 18F-Fluoride Kinetics: Evaluation of Simplified Methods.

UNLABELLED: (18)F-fluoride PET is a promising noninvasive method for measuring bone metabolism and bone blood flow. The purpose of this study was to assess the performance of various clinically useful simplified methods by comparing them with full kinetic analysis. In addition, the validity of deriving bone blood flow from K1 of (18)F-fluoride was investigated using (15)O-H2O as a reference. METHODS: Twenty-two adults (mean age ± SD, 44.8 ± 25.2 y), including 16 patients scheduled for bone surgery and 6 healthy volunteers, were studied. All patients underwent dynamic (15)O-H2O and (18)F-fluoride scans before surgery. Ten of these patients had serial PET measurements before and at 2 time points after local bone surgery. During all PET scans, arterial blood was monitored continuously. (18)F-fluoride data were analyzed using nonlinear regression (NLR) and several simplified methods (Patlak and standardized uptake value [SUV]). SUV was evaluated for different time intervals after injection and after normalizing to body weight, lean body mass, and body surface area, and simplified measurements were compared with NLR results. In addition, changes in SUV and Patlak-derived fluoride influx rate (Ki) after surgery were compared with corresponding changes in NLR-derived Ki. Finally, (18)F-fluoride K1 was compared with bone blood flow derived from (15)O-H2O data, using the standard single-tissue-compartment model. RESULTS: K1 of (18)F-fluoride correlated with measured blood flow, but the correlation coefficient was relatively low (r = 0.35, P < 0.001). NLR resulted in a mean Ki of 0.0160 ± 0.0122, whereas Patlak analysis, for the interval 10-60 min after injection, resulted in an almost-identical mean Ki of 0.0161 ± 0.0117. The Patlak-derived Ki, for 10-60 min after injection, showed a high correlation with the NLR-derived Ki (r = 0.976). The highest correlation between Ki and lean body mass-normalized SUV was found for the interval 50-60 min (r = 0.958). Finally, changes in SUV correlated significantly with those in Ki (r = 0.97). CONCLUSION: The present data support the use of both Patlak and SUV for assessing fluoride kinetics in humans. However, (18)F-fluoride PET has only limited accuracy in monitoring bone blood flow.

Bone scintigraphy as a diagnostic method in unilateral hyperactivity of the mandibular condyles: a review and meta-analysis of the literature.

Bone scan analyses and clinical assessment are used to diagnose unilateral condylar hyperactivity (UCH). This review compares the diagnostic accuracy of planar and SPECT bone scans. Studies diagnosing patients with possible UCH using bone scans, published between 1968 and 2008, were included in this review. Of 15 articles that met the inclusion criteria, 7 presented results in sufficient detail to calculate index test characteristics. Three control studies show that the difference in uptake values of the left and right condylar regions in the normal population does not exceed 10%. The pooled sensitivity of the planar bone scan (n=130) was 0.71 (95% confidence interval: 0.57-0.82), which was significantly lower (p=0.04) than that of the bone SPECT technique (n=88), which was 0.90 (0.79-0.97). The pooled specificity of the SPECT scan was 0.95 (0.82-0.99), which did not significantly differ (p=0.58) from that of the planar scan (0.92 (0.83-0.97)). Future studies should include a diagnostic analysis of the data, including two-by-two contingency tables, so the accuracy of the diagnostic test may be evaluated. Bone scans are best performed using SPECT, conducting a quantitative analysis by calculating the percentile differences between the left and right condylar regions.

Comparison of planar bone scintigraphy and single photon emission computed tomography in patients suspected of having unilateral condylar hyperactivity.

OBJECTIVE: A comparison is made of single photon emission computed tomography (SPECT) and planar bone scintigraphy in the diagnosis of patients with suspected unilateral condylar hyperactivity (UCH). STUDY DESIGN: The subjects comprised 56 patients with suspected UCH who underwent SPECT and regular planar bone scans. Accuracy of SPECT and planar scintigraphy were compared using left-right condylar activity. RESULTS: Of the 56 patients, 29 were diagnosed with active UCH and 27 without UCH. The mean relative activity of the hyperactive condylar region in the planar scans was 53.5% (SD +/- 2.3%), which was significantly higher in the SPECT scan with a mean value of 60.5% (SD +/- 5.4%), P < .005 (t = 8.951). Receiver operating curves (ROC) were clearly in favor of SPECT over the planar bone scan. The area under the curve (AUC) of the planar ROC was 0.87 +/- 0.049 while that of the SPECT ROC was 0.97 +/- 0.024. The optimal cut-off value for planar scanning was 52%, yielding a sensitivity of 67% and a specificity of 85%. For SPECT scanning, the optimal cut-off was 56%, resulting in a sensitivity of 93% and a specificity of 96%. CONCLUSIONS: It can be concluded that in patients with a clinically suspected active UCH, SPECT scanning is the preferred diagnostic tool rather than planar bone scanning. However, treatment planning should be done in combination with clinical assessment of progressive mandibular asymmetry as well as taking into account the patient history.

Quantitative analysis of planar bone scintigraphy in patients with unilateral condylar hyperplasia.

OBJECTIVE: This study compares quantitative analysis of planar bone scintigrams with visual interpretation in patients having unilateral condylar hyperplasia (UCH) and normal control subjects. The possibility of using a bony structure in a region near the condyle as an objective measurement of bone activity is assessed. STUDY DESIGN: Planar bone scintigrams from 20 subjects suspected of having active UCH were analyzed both qualitatively and quantitatively. Bone activity was assessed in both condyles as well as in reference sites in the cervical spine and the skull. Percentile activities for both condyle regions and ratios using condyle activity versus reference regions were assessed. RESULTS: All UCH patients had unilateral increased activity on qualitative visual interpretation of the bone scan. The mean percentile activities of the affected and unaffected condyles in the UCH group were significantly different at 55.3% and 44.7%, respectively (P < .001). No significant difference was found in the control group, with the ratios between left and right condyle being 49.5% and 50.5%, respectively (P = .46). In the ratios between the region of interest (ROI) in the condyles versus the ROIs selected for the cervical spine and the skull, a significant difference was noticed in the UCH group; however, there was a considerable overlap between condyle and reference ROI ratios. Symmetrical uptake of diphosphonate reliably excluded continued asymmetrical growth of the condyles. CONCLUSIONS: Quantitative analysis of planar scintigrams in unilateral condylar hyperplasia patients was not found to be superior to qualitative visual interpretation of the scans. Because of a considerable overlap in condyle/reference ROI ratios, quantified ratios did not seem to be clinically helpful in the differentiation of a hyperplastic condyle from a normal condyle. In the case of unilateral increased condylar uptake of diphosphonate, clinical assessment is mandatory.