Do cone‐beam computed tomography low‐dose protocols affect the evaluation of the temporomandibular joint?

Abstract

Background: There is no established acquisition protocol based on scientific evidence for the acquisition of cone-beam computed tomography (CBCT) exams to evaluate the temporomandibular joint (TMJ). Objectives:To evaluate the influence of acquisition protocols and jaw positioning on the diagnostic accuracy of TMJ condylar morphological alterations (CMA), dimension, position and excursion.Methods: Thirty-six TMJs on 18 dry skulls were imaged using a CBCT unit (OP300 Maxio, Instrumentarium, Tuusula, Finland) at two exposure settings (4.5 and 6.3 mA), three voxel resolutions (0.085, 0.125 and 0.280 mm), three jaw positions (concentric, anteriorised and posteriorised) and three jaw excursions (normoexcursion, hyperexcursion and hypoexcursion). The macroscopic anatomy examination and highresolution CBCT images were used as ground truth for CMA. Twenty-five TMJs had at least one CMA with 11 healthy TMJs serving as controls. Three experienced oral and maxillofacial radiologists evaluated the parasagittal images for the presence of CMA, position and excursion and measured dimensions. The area under the ROC curve, sensitivity and specificity were calculated. Weighted Kappa (α = 0.05) was used to determine intra-and interexaminer reliability and comparisons between dependent variables analysed by Analysis of Variance at an a prior level of significance of 0.05. Results:The agreement of the evaluation of the position and excursion with the reference standard was high, independent of the protocol (range, 0.75-0.91). Various combinations of acquisition protocols and jaw position did not influence the CMA evaluation. Erosion was overdiagnosed in protocols with larger voxel sizes and the detection of osteophytes greater in images with smaller voxel sizes. The anteroposterior dimension was greater in the open jaw position (p < .05). Conclusion:CBCT protocols using reduced radiation exposure from the CBCT machine evaluated in this study can be used to assess condylar morphology, dimension, position and excursion, without compromising diagnostic performances for these parameters.

Do voxel size and filter application on CBCT images improve the diagnosis of condylar morphological alterations? An ex vivo study

“…The later might be related to the high complexity and difficulty in detecting small and discrete alterations of the condyle and also classifying among different types. Also, previous studies have shown low intra and inter‐evaluators agreement when assessing condylar morphological alterations 29,30 . Furthermore, when looking to our outcomes, it is possible to observe that lower severity alterations prevailed above higher severity alterations, which implies in a more difficult diagnosis.…”

“…Also, previous studies have shown low intra and inter-evaluators agreement when assessing condylar morphological alterations. 29,30 Furthermore, when looking to our outcomes, it is possible to observe that lower severity alterations prevailed above higher severity alterations, which implies in a more difficult diagnosis.…”

“…Regarding the detection of condylar morphological alterations, a study showed that the voxel size did not influence the diagnosis of erosions, flattening or condylar deformations. 29 In relation to the detection of sclerosis, a smaller voxel size with a higher field of view size performed better. 30 We believe that the detection of condylar morphological alterations is alteration-dependent, and, therefore, different results are found for each one of them.…”

“…However, it is important to highlight that the voxel size reduction results in an increased image noise 26 and, since the voxel size may be directly related to the radiation dose, it is important to keep the ALADAIP 28 concept in mind. Regarding the detection of condylar morphological alterations, a study showed that the voxel size did not influence the diagnosis of erosions, flattening or condylar deformations 29 . In relation to the detection of sclerosis, a smaller voxel size with a higher field of view size performed better 30 .…”

Assessment of the location and extent of bone erosions in mandibular condyles using multislice computed tomography

“…Additionally, Reis et al (2022) stated that acquisition protocols (voxel size and mA) and jaw position (closed and open) did not influence the detection of TMJ degenerative joint disease changes alterations (de Oliveira Reis et al, 2022). …”