Carrol P. Saridin

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.

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.

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.

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.

Comparison of different analytical methods used for analyzing SPECT scans of patients with unilateral condylar hyperactivity

This study aimed to compare different analytical methods and identify the optimal analysis method to distinguish patients with unilateral condylar hyperactivity (UCH) from those with inactive condyles. Single-photon emission computed tomography (SPECT) scans of patients with progressive and nonprogressive mandibular asymmetry (each group, n=26), were analyzed using the region of interest technique. Sensitivity, specificity and receiver operating characteristic (ROC) curves were calculated for the different analytic methods. The ROC curve illustrates that UCH can be diagnosed significantly better by determining the percentile bone activity in both condyles. The area under the curve (AUC) of the percentile comparison between the affected and contralateral condyles was 0.93+/-0.04, that for the condyle/clivus ratio was 0.75+/-0.07 and for the condyle/cervical spine (CS) ratio 0.57+/-0.08. Sensitivity for the condyle/clivus ratio was 65% and specificity 61%. Sensitivity for the condyle/CS ratio was 85% and specificity 31%. For the percentile difference of the condyles, sensitivity and specificity were 88%. For UCH patients, direct comparison of bone activity between the affected and contralateral condyle in SPECT scans is the analysis method of choice. Comparison of condylar bone activity to reference bone activity does not have additional value in the diagnosis of UCH.

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.