Detection accuracy of condylar bony defects in Promax 3D cone beam CT images scanned with different protocols

Assessment of condylar anatomy and degenerative changes in temporomandibular joint disorders - A scoping review

Temporomandibular disorders (TMDs) are a group of conditions that cause pain and dysfunction in the temporomandibular joint (TMJ) and muscles that control mandibular movement. In most cases, the etiology is unclear and is considered multifactorial. Recent research suggests that some forms of TMD could be associated with specific TMJ morphological characteristics. This study aims to provide a review of the reported anatomical and degenerative morphological condylar characteristics of subjects with a clinical diagnosis of TMD as described with the use of CBCT imaging, as well as the detection of potential predisposing anatomical factors. This review was developed and reported in accordance with the PRISMA-ScR Checklist. A comprehensive search was performed in five databases. Reports were screened by two independent reviewers based on preselected inclusion and exclusion criteria. 45 studies were included in this review. The most frequently reported degenerative changes associated with TMD were condylar surface erosion, flattening, osteophytes, and sclerosis. Anatomical characteristics included a small condylar size and a posterior position of the condylar head in the TMJ. The anterosuperior area of the condylar head appears to be the most frequently affected. More studies are required to determine potential specific predisposing anatomical characteristics.

Dosimetric evaluation for temporomandibular joint cone beam computed tomography exams using different field of view

Objectives.To optimize the absorbed organ dose in relation to the field of view for temporomandibular joint examinations in four cone beam computed tomography devices.Methods.An anthropomorphic adult head and neck phantom, and 192 LiF dosimeters (TLD-100) were used. The dosimeters were placed in the region corresponding to the lens, parotid glands, submandibular glands, and thyroid. Small, medium and large FOVs were selected on Orthopantomograph OP300 Maxio, PaX-i3D Smart, ORTHOPHOS XG, and i-CAT Next Generation device when it was possible.Results.A wide range of absorbed dose values was recorded for all organs due to the different exposure parameters of each device. The radiosensitive organ with the highest dose was the parotid glands. The devices with 5 × 5 cm FOV recorded a lower dose in this protocol, while for the device without a small FOV (≤5 × 5 cm), the lowest dose was observed with the large FOV (6 × 16 cm).Conclusions.We recommend a double exposure with an FOV of 5 × 5 cm in the OP300 Maxio, PaX-i3D Smart, and ORTHOPHOS XG device, while in the i-CAT Next Generation device, a single exposure FOV of 6 × 16 cm is indicated.

Evaluation of various low-dose cone-beam computed tomography protocols in the diagnosis of specific condylar defects

INTRODUCTION

This study aimed to determine the identifiability and measurement accuracy of defined bony defects of the temporomandibular joint (TMJ) in cone-beam computed tomographies, depending on different milliampere-second (mAs)-reduced protocols.

METHODS

Defined artificial defects were prepared on 30 condyles from 15 intact pig heads, with a maximum of surrounding soft tissue preserved. Three-dimensional imaging was performed using ProMax 3D Mid (Planmeca, Helsinki, Finland). The scan protocol with maximum resolution and without mAs-reduction was defined as control. Twenty-six mAs-reduced imaging protocols were analyzed by 1 examiner regarding the protocol-specific measurement accuracy. Defect depth (DD) was divided into 3 categories: I, <2 mm; II, 2-3 mm; and III, >3 mm. The protocol-specific sensitivity and specificity were evaluated in relation to localization and defect size as determined from the results of 3 examiners.

RESULTS

There was a significant difference from the control protocol in DD measurement in 8 mAs-reduced protocols, P <0.001-0.027. In most protocols, there was no significant difference in measurement accuracy concerning defect size and localization. The mean sensitivity reached values between 93.3% and 98.6% and differed significantly among protocols (P = 0.002). The mean specificity amounted to 97.0%-98.1% and did not differ among protocols (P = 0.462). The specificity of DD III (99.1%) was higher than DD I (97.7%) and DD II (97.1%). There was a significant difference in specificity and sensitivity concerning defect localization (P <0.001).

CONCLUSIONS

This study showed that mAs-reduced cone-beam computed tomographies protocols are suitable for the analysis of defined osseous TMJ defects. When 3-dimensional TMJ imaging is indicated because of potential erosive defects, validated mAs-reduced scan protocols should be applied instead of high-definition protocols.

Evaluation of the geometric accuracy of computed tomography and microcomputed tomography of the articular surface of the distal portion of the radius of cats

OBJECTIVE

To evaluate accuracy of articular surfaces determined by use of 2 perpendicular CT orientations, micro-CT, and laser scanning.

SAMPLE

23 cat cadavers.

PROCEDURES

Images of antebrachia were obtained by use of CT (voxel size, 0.6 mm) in longitudinal orientation (CT_LO images) and transverse orientation (CT_TO images) and by use of micro-CT (voxel size, 0.024 mm) in a longitudinal orientation. Images were reconstructed. Craniocaudal and mediolateral length, radius of curvature, and deviation of the articular surface of the distal portion of the radius of 3-D renderings for CT_LO, CT_TO, and micro-CT images were compared with results of 3-D renderings acquired with a laser scanner (resolution, 0.025 mm).

RESULTS

Measurement of CT_LO and CT_TO images overestimated craniocaudal and mediolateral length of the articular surface by 4% to 10%. Measurement of micro-CT images underestimated craniocaudal and mediolateral length by 1%. Measurement of CT_LO and CT_TO images underestimated mediolateral radius of curvature by 15% and overestimated craniocaudal radius of curvature by > 100%; use of micro-CT images underestimated them by 3% and 5%, respectively. Mean ± SD surface deviation was 0.26 ± 0.09 mm for CT_LO images, 0.30 ± 0.28 mm for CT_TO images, and 0.04 ± 0.02 mm for micro-CT images.

CONCLUSIONS AND CLINICAL RELEVANCE

Articular surface models derived from CT images had dimensional errors that approximately matched the voxel size. Thus, CT cannot be used to plan conforming arthroplasties in small joints and could lack precision when used to plan the correction of a limb deformity or repair of a fracture.

Association between the Anatomy of the Mandibular Canal and Facial Types: A Cone-Beam Computed Tomography Analysis

We evaluated the anatomical variations of the mandibular canal associated with various facial types, age, sex, and side of the face studied. We analyzed 348 hemimandibles in subjects without a history of trauma, lesions in the lower arch, or orthognathic or repair surgery in the posterior mandible. Facial type was determined using the VERT index. The canal path was classified as Type 1 (a large, single structure passing very close to the root tips); Type 2 (a canal passing closest to the mandibular base); and Type 3 (a canal present in the posterior mandibular region, with a lower canal running through the mandibular branch, reaching the anterior region). Bifid canals (type 3) were classified into four categories according to the course and number of mandibular canals. The brachyfacial and mesofacial types presented a Type 1 canal in 95.5% (n=166) of subjects, in dolichofacial types, 68.2% (n=45) presented a Type 2 canal, while in the mesofacial type, a lower prevalence of the bifid mandibular canal was observed (13.0%, n=23) than in the other facial types. The bifid canal showed significant association with facial type only (p < 0.05), but no significant association was observed with the anterior loop type (p > 0.05). Facial type is significantly associated with the path and morphological variations of the mandibular canal, independently of the side of the face studied, age, and sex.

Comparison of the Bony Changes of TMJ in Patients With and Without TMD Complaints Using CBCT

STATEMENT OF THE PROBLEM

Temporomandibular joint disorders (TMD) may show a poor correlation between their clinical findings and radiological characteristics.

PURPOSE

The aim of this study was to assess the osseous alterations of temporomandibular joint (TMJ) in symptomatic and asymptomatic subjects by employing cone beam computed tomography (CBCT) images.

MATERIALS AND METHOD

In this study, CBCT images of 120 temporomandibular joints in 30 patients with TMJ disorder and 30 age- and sex-matched individuals without TMJ complaints were evaluated. Osteoarticular derangements of the joint were assessed by two experienced examiners. Data was statistically analyzed with SPSS software using chi-square test (p <0.05).

RESULTS

Out of 120 CBCT images (60 in each group), at least one osseous change was observed in 90% and 86.7% joints in symptomatic and asymptomatic subjects, respectively. There were no significant differences between symptomatic and asymptomatic subjects regarding frequency of osteoarticular changes including flattening (73.3% vs. 75%), irregularity (36.7% vs. 48.3%), sclerosis (20% vs. 8.3%), cyst (3.3% vs. 3.3%), erosion (13.3% vs. 21.7%), hypoplasia (3.3% vs. 5%), ankylosis (1.7% vs. Zero), osteophyte (43.3% vs. 40%), decrease joint space (3.3% vs. 3.3%), and increase joint space (5% vs. 5%). (p> 0.05).

CONCLUSION

By employing CBCT as a modern diagnostic imaging tool, findings of this study revealed that the frequency of various temporomandibular joint alterations on CBCT images is comparable in patients with and without TMD complaints, suggesting that some people with TMJ structural damage may not display clinical manifestations. Moreover, CBCT imaging might not be necessary for TMD patients and more attention should be given to clinical examination.

Morphometric Analysis of the Mental Foramen Using Cone-Beam Computed Tomography

This study evaluated the effects of age and sex on the location and size of the mental foramen (MF). A total of 104 cone-beam computed tomography (CBCT) scans from patients' aged 18–80 years were selected. Images were evaluated using the following parameters: position and size of the MF, and Distances A (distance from the upper limit of the MF to the apex of the first lower premolar), B (distance from the upper cortical border of the MF to the alveolar crest), and C (distance from the border of the MF to the base of the mandible). Results revealed that the location of the MF was predominantly apical (44.4%), between the long axes of the premolars, at an average distance of 4.92 mm from the root of the first lower premolar. The height of the MF was significantly different between both sexes (3.41 and 2.99 mm, resp.; mean height: 3.11 mm; P=0.003). The MF was located on average at 11.21 mm from the alveolar crest and 12.31 mm from the base of the mandible; the former measurement was significantly different between both sexes (13.13 and 11.98 mm, resp.; P ≤ 0.001). In conclusion, the location of the MF was predominantly apical between the long axes of the premolars, and the mean size and distance of the MF were greater in men.

Impact of routine open-mouth osseous temporomandibular joint tomography on diagnosis and therapeutic options

OBJECTIVES

The aim of this study was to evaluate the impact of routine open mouth osseous temporomandibular joint (TMJ) tomography on diagnosis and treatment planning of TMJ conditions. Investigating the need for such images is important to justify the additional radiation exposure imparted by such procedures.

STUDY DESIGN

The records of patients who underwent closed- and open-mouth osseous TMJ tomography (planar film tomography up to the beginning of 2006; cone beam computed tomography from 2006 onward) were reviewed. Three examiners formulated a diagnosis and treatment plan based on the history, clinical findings, and tomography interpretation reports of closed-mouth images. Then they reviewed the interpretations of the open-mouth images and recorded whether they would change their original diagnosis and/or treatment plan on the basis of the findings. Descriptive analysis of the results was performed.

RESULTS

The impact of routine open-mouth imaging on diagnosis and treatment planning was variable among the examiners. Examiners 1, 2, and 3 had a change in diagnosis in 7%, 5%, and 3% of cases, respectively, and a change in treatment plan in 1%, 1%, and 8%, respectively.

CONCLUSIONS

Routine open-mouth osseous TMJ tomography had a minimal impact on diagnosis and treatment planning of TMJ conditions, which varied according to the treating clinician.

The detection accuracy of cone beam CT for osseous defects of the temporomandibular joint: a systematic review and meta-analysis

The purpose of this review was to evaluate whether cone-beam computed tomography (CBCT) is reliable for the detection of bone changes of the temporomandibular joint (TMJ). Studies collected from the PubMed, Web of Science, Cochrane Library, ScienceDirect, Embase, Wanfang and CNKI databases were searched, and the publishing time was limited from January 1990 to December 2015. Eight studies (23 experimental research groups) were eventually included for further analysis. The pooled sensitivity was 0.67 and the pooled specificity was 0.87, which leads to a relatively large area (0.84) under the Receiver Operating Characteristic (ROC) curve. The related pooled positive likelihood ratio (+LR) and the pooled negative likelihood ratio (−LR) were 5.2 and 0.38, respectively. The subgroup analysis was conducted for four subgroups categorized by voxel size (≤0.2; >0.2, ≤0.3; >0.3, ≤0.4; >0.4, and ≤0.5 (mm)), and the “>0.4, ≤0.5” subgroup had a higher pooled sensitivity and pooled specificity than the other groups. The present study demonstrates that CBCT has a relatively high diagnostic accuracy for TMJ bone changes, although its reliability is limited. Voxel size did not play a role in the accuracy of CBCT.

Digital panoramic radiography for diagnosis of the temporomandibular joint: CBCT as the gold standard

Three-dimensional imaging modalities have been reported to be more accurate than panoramic radiographs (PR) for the assessment of bone components of the temporomandibular joint (TMJ). No exact prior information is available that demonstrates which specific limitations occur in terms of TMJ diagnosis when using PR for this purpose. This study aimed to assess the clinical validity of digital panoramic radiography (DPR) when diagnosing morphological disorders of the TMJ using cone-beam computed tomography (CBCT) images as the gold standard. A sample composed of TMJ images (N = 848), including 212 DPR and 212 CBCT images obtained from the same patient, was used to assess any morphological changes in the TMJ. Four appraisers diagnosed all of the DPR images, whereas the CBCT images were used to establish the gold standard. The reliability of each appraiser's response pattern was analyzed using the Kappa test (κ), and diagnostic tests were performed to assess each appraiser's performance using a significance level setting of 5% (α = 0.05). Reliability of each appraiser's response pattern compared to the gold standard ranged from a slight-to-moderate agreement (0.18 ≤ κ ≤ 0.45); and among the different appraisers, the response pattern showed a fair agreement (0.22 ≤ κ ≤ 0.39). Diagnostic tests showed a wide range among the different possible morphological changes diagnosed. DPR does not have validity when diagnosing morphological changes in the TMJ; it underestimates the radiological findings with higher prevalence, and thus, it cannot be used effectively as a diagnostic tool for bone components within this region.

Temporomandibular joint diagnostics using CBCT

The present review will give an update on temporomandibular joint (TMJ) imaging using CBCT. It will focus on diagnostic accuracy and the value of CBCT compared with other imaging modalities for the evaluation of TMJs in different categories of patients; osteoarthritis (OA), juvenile OA, rheumatoid arthritis and related joint diseases, juvenile idiopathic arthritis and other intra-articular conditions. Finally, sections on other aspects of CBCT research related to the TMJ, clinical decision-making and concluding remarks are added. CBCT has emerged as a cost- and dose-effective imaging modality for the diagnostic assessment of a variety of TMJ conditions. The imaging modality has been found to be superior to conventional radiographical examinations as well as MRI in assessment of the TMJ. However, it should be emphasized that the diagnostic information obtained is limited to the morphology of the osseous joint components, cortical bone integrity and subcortical bone destruction/production. For evaluation of soft-tissue abnormalities, MRI is mandatory. There is an obvious need for research on the impact of CBCT examinations on patient outcome.