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Evaluation of acute soft tissue injury of the temporomandibular joint (TMJ) with type I–VI fractures immediately after trauma and investigation of the longitudinal evolution including response to conservative treatment using MRI. The joints of 24 patients with 33 condylar fractures (15 unilateral, nine bilateral) were imaged on a 1 Tesla MR system within the first 24 h post-trauma. 12 of these patients with 16 condylar fractures (eight unilateral, four bilateral) were clinically re-evaluated using MRI after 3 months of closed treatment. The position, morphology, and signal intensities of the disc, capsule, retrodiscal tissue, and osseous structures were documented. In the acute phase, disc displacements (DDs) were diagnosed in 8 out of 33 joints with fracture, including posterior DDs in two joints and tears of the inferior retrodiscal lamina in 11 joints. The follow-up MRI in 12 patients revealed new DD in four joints on the fractured side (FS) including a posterior DD and an increased degree of displacement, and new DDs in two joints in the non-fractured side (NFS). Preexisting and traumatic DD and soft tissue injuries are frequent findings in patients with condylar fracture. Independent of the degree of trauma, condylar fractures may determine the subsequent development of DD on both FS and NFS. Early MR imaging may help initiate well-directed specific measures for better outcomes in the acutely injured TMJ. [ABSTRACT FROM AUTHOR]

To evaluate the mandibular bone structure of patients with hyperlipidemia by fractal dimension (FD) analysis and panoramic radiomorphometric indices including mandibular cortical thickness measurement, panoramic mandibular index (PMI), mandibular cortical index (MCI) and to compare with the healthy group. In total, 60 panoramic radiographs were included, including panoramic radiographs of 30 individuals with hyperlipidemia and 30 individuals with systemically healthy. FD analysis in the mandibular condyle, angle of the mandible, the distal side of the second premolar and anterior to mental foramen, PMI, MCI, and mandibular cortical thickness measurements were evaluated on radiographs. Independent samples t-test was used for differences between healthy and hyperlipidemia groups with regard to age and PMI. Repeated measurement of variance with one within and one between factors in the comparison of four regions and two groups in terms of FD and cortical thickness measurements. Following this analysis, significant differences were detected by post-hoc Sidak test. Fisher-Freeman-Halton analysis was applied to determine the relationship between categorical variables. FD values of the hyperlipidemic patients were found to be lower than the healthy group. Between the hyperlipidemic and healthy groups, there was a difference in the angle of the mandible FD values (p = 0.020). There were no differences in the cortical thickness measurements and PMI between the groups (p > 0.05). There was a difference in MCI values between the groups (p < 0.05). The trabecular structure of the angle of the mandible and the cortical bone structure of the mandible were found to be negatively affected by hyperlipidemia. [ABSTRACT FROM AUTHOR]

The present study aimed to verify the classification performance of deep learning (DL) models for diagnosing fractures of the mandibular condyle on panoramic radiographs using data sets from two hospitals and to compare their internal and external validities. Panoramic radiographs of 100 condyles with and without fractures were collected from two hospitals and a fivefold cross-validation method was employed to construct and evaluate the DL models. The internal and external validities of classification performance were evaluated as accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve (AUC). For internal validity, high classification performance was obtained, with AUC values of >0.85. Conversely, external validity for the data sets from the two hospitals exhibited low performance. Using combined data sets from both hospitals, the DL model exhibited high performance, which was slightly superior or equal to that of the internal validity but without a statistically significant difference. The constructed DL model can be clinically employed for diagnosing fractures of the mandibular condyle using panoramic radiographs. However, the domain shift phenomenon should be considered when generalizing DL systems. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess radiographical changes on temporomandibular joint (TMJ) in relation the autoimmune rheumatic diseases and the medicines that treat this diseases with cone beam computed tomography(CBCT). 65 people with rheumatoid diseases were included in the study and divided into five subgroups according to drugs they used. Condyle height (CH), anteroposterior dimension (APD), mesiolateral dimension (MLD) and superior joint space (SJS) were measured in order to evaluate mandibular condyle dimensions. Further, were evaluated in terms of osteoarthritic changes such as erosion, flattening, osteophyte and subchondral cyst in the mandibular condyle. TMJ measurements were compared between study-control groups and subgroups by using Student's t-test, Mann-Whitney-U test, one-way analysis of variance (ANOVA) and Kruskal-Wallis test. The association between osteoarthritic features, rheumatoid status was tested by using χ2 test. Observers were blinded to all groups. Cohen κ values (0853–0945) and Spearman's correlation coefficient (0.959–0.997) indicated high interexaminer reliability. Condylar dimentions were significantly lower in CH and SJS in rheumatic diseases group (p < 0.001), however APD (p = 0,681) and MLD (p = 0,757) was not different significantly. Osteoarthritic changes such as erosion (p < 0.001), flattening (p = 0.005), osteophyte (p = 0.001) and subchondral cyst (p = 0.001) were significantly higher in the patient group. None of the parameters were different significantly according to subgroups determined according to drugs used(p > 0.05). Degenerative changes may cause decrease in condyle size and changes in condyle position. It is a process that can continue despite the use of antirheumatic or immunosuppressive drugs. All of these can become the source of possible TMJ problems. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to evaluate the reliability of AI‐generated STL files in diagnosing osseous changes of the mandibular condyle and compare them to a ground truth (GT) diagnosis made by six radiologists. Methods: A total of 432 retrospective CBCT images from four universities were evaluated by six dentomaxillofacial radiologists who identified osseous changes such as flattening, erosion, osteophyte formation, bifid condyle formation, and osteosclerosis. All images were evaluated by each radiologist blindly and recorded on a spreadsheet. All evaluations were compared and for the disagreements, a consensus meeting was held online to create a uniform GT diagnosis spreadsheet. A web‐based dental AI software was used to generate STL files of the CBCT images, which were then evaluated by two dentomaxillofacial radiologists. The new observer, GT, was compared to this new STL file evaluation, and the interclass correlation (ICC) value was calculated for each pathology. Results: Out of the 864 condyles assessed, the ground truth diagnosis identified 372 cases of flattening, 185 cases of erosion, 70 cases of osteophyte formation, 117 cases of osteosclerosis, and 15 cases of bifid condyle formation. The ICC values for flattening, erosion, osteophyte formation, osteosclerosis, and bifid condyle formation were 1.000, 0.782, 1.000, 0.000, and 1.000, respectively, when comparing diagnoses made using STL files with the ground truth. Conclusions: AI‐generated STL files are reliable in diagnosing bifid condyle formation, osteophyte formation, and flattening of the condyle. However, the diagnosis of osteosclerosis using AI‐generated STL files is not reliable, and the accuracy of diagnosis is affected by the erosion grade. [ABSTRACT FROM AUTHOR]

Objective: Recently, single‐photon emission CT/CT (SPECT/CT) plays an important role in assessing patients with medication‐related osteonecrosis of the jaw (MRONJ). The aim of this study was to investigate maximum and mean standardized uptake values (SUVs) of MRONJ with bone SPECT/CT, especially comparison of mandibular pathologies, control and temporomandibular joints. Methods: 61 mandibular patients with MRONJ who underwent bone SPECT/CT were included in this study. The maximum and mean SUVs of the lesion, right and left sides of the lesion, opposite side of the lesion as control, right and left temporomandibular joints were analyzed using a workstation and software. The SUVs of MRONJ were analyzed using one‐way analysis of variance with Tukey's honestly significant difference test. Patient characteristics with MRONJ and SUVs were analyzed using Mann–Whitney U test. P-values less than 0.05 were considered to indicate statistical significance. Results: The maximum and mean SUVs for opposite side of the lesions (4.4 ± 2.0 and 1.8 ± 0.7) were significantly lower than those for mandibular lesions (18.3 ± 8.1 and 6.3 ± 2.8), right side of the lesions (8.1 ± 3.9 and 2.9 ± 1.3) and left side of the lesions (8.1 ± 3.9 and 2.8 ± 1.4), respectively. The maximum and mean SUVs for right and left sides of the lesions, and opposite side of the lesions, right and left temporomandibular joints were not significant difference. Furthermore, the maximum SUVs of the mandibular lesions were a significant difference for age and staging. Conclusions: The maximum and mean SUVs with SPECT/CT can be useful in the quantitative management of MRONJ patients. [ABSTRACT FROM AUTHOR]

Objectives: To investigate whether variations in head positioning may influence the reproducibility of cone‐beam CT (CBCT) three‐dimensional (3D) segmented models of the mandibular condyle. Methods: Five fresh frozen cadaver heads were scanned in four different positions: reference position (RP) and a set of three tilted alternative head positions (AP) in anteroposterior direction (AP1: 2 cm anterior translation, AP2: 5° pitch rotation, AP3: 10° pitch rotation). Surface models of mandibular condyles were constructed and compared with the condylar reference position using voxel‐based registration. Descriptive statistics and a linear mixed‐effects model were performed to compare condylar volumetric differences and root mean square (RMS) distance between surfaces of AP vs RP. Results: The mean differences in condylar volumes of AP vs RP were 14.1 mm³ (95% CI [−79.3, 107.4]) for AP1, 1.0 mm³ (95% CI [−87.2, 89.2]) for AP2 and 0.1 mm³ (95% CI [−88.3, 88.4]) for AP3. Mean and absolute volumetric differences did not exceed earlier reported intraoperator differences of 30 mm³. The RMS distance values obtained per group were 0.12 mm (95% CI [0.05,0.20]) for AP1, 0.17 mm (95% CI [0.10, 0.22]) for AP2 and 0.17 mm for AP3 (95% CI [0.10,0.22]). The confidence intervals (CI) for RMS distance remained far below the threshold for clinical acceptability (0.5 mm). Conclusions: Within the limits of the present study, it is suggested that tilted head positions may affect the reproducibility of 3D condylar segmentation, thereby influencing outcome in repeated CBCT scanning. Nevertheless, observed differences are unlikely to have a meaningful impact on clinical patient diagnosis and management. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to develop an algorithm to distinguish the patients with bisphosphonate‐related osteonecrosis of the jaws (BRONJ) from healthy controls using CBCT images by evaluating both trabecular and cortical bone changes through the whole body of the mandibular bone. Methods: Patient data set was created from axial CBCT images of 7 BRONJ patients (28 slices) and 8 healthy controls (27 slices). The healthy bone of healthy controls, bone sclerosis of BRONJ patients, bone necrosis of BRONJ patients, and normal appearing bone of BRONJ patients (NBP) were labeled on CBCT images by three maxillofacial radiologists. Proposed algorithm had preparation and background cancellation, mandibular bone segmentation and centerline determination, spatial transformation of gray values, and classification steps. Results: Significant differences between the statistical moments (mean, variance, skewness, kurtosis, standard error, median, mode and coefficient of variance) of healthy and diseased (bone sclerosis and necrosis) groups were observed (p = 0.000, p < 0.05). Also, variations were noted between healthy controls and NBP of BRONJ patients (p = 0.000, p < 0.05). The statistical moments were utilized to develop the algorithm which has resulted with accuracy of 0.999, sensitivity of 0.998, specificity of 0.998, precision of 1, recall of 0.998, AUC of 1, and F1 score of 0.999 in identification of BRONJ patients from healthy ones. Conclusion: The proposed algorithm differentiated the mandibular bones of the healthy and the BRONJ patients with high accuracy in the present test sample. [ABSTRACT FROM AUTHOR]

Objective: Pre-surgical CBCT has been suggested before removal of the mandibular third molar. Currently, the standard-of-care is two-dimensional (2D) panoramic imaging. The aim of this randomized controlled trial was to analyse possible differences in neurosensoric disturbances of the inferior alveolar nerve between patients undergoing either panoramic imaging or CBCT before surgical removal of the mandibular third molar. Furthermore, the aim was to perform a sensitivity analysis to assess the statistical significance of different assumptions related to sample size calculations. Methods: 230 patients were randomized to a scan group and a non-scan group. All patients were referred from practicing dentists in the Copenhagen area. Inclusion criteria were overlap of the root complex and the mandibular canal on a 2D radiographic image. Central allocation of the randomization code and double blind settings were established. The surgical removal was performed in a specialized surgical practice geographically and personally separated from the study practice. Registration of neurosensoric anomalies was performed with a Semmes-Weinstein test and a visual analogue scale questionnaire pre- and post-surgically. Results: In the scan group (n = 114), 21 episodes of neurosensoric disturbances were registered and in the non-scan group (n = 116), 13 episodes of neurosensoric disturbances were registered. There was no statistically significant difference between the two groups (p = 0.14). Performing a sensitivity analysis confirmed that CBCT was not superior to panoramic imaging in avoiding neurosensoric disturbances. Conclusions: The use of CBCT before removal of the mandibular third molar does not seem to reduce the number of neurosensoric disturbances. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to determine the visibility of the mandibular canal (MC) in CBCT images and if the visibility of the MC is affected by gender, location and/or age. Methods: CBCT images were evaluated for the visibility of the MC by a board-certified oral and maxillofacial radiologist, a board-certified periodontist and a periodontics resident. Representative slices were examined for the first premolar (PM1), second premolar (PM2), first molar (M1) and second molar (M2) sites by all examiners. The visibility of the MC was registered as either present or absent. Results: 360 total CBCT cross-sectional images were examined, with the MC identified in 204 sites (56%). Age had a significant effect on MC visibility, but it differed by location: for PM1, age 47-56 had lower visibility than age 65+ (p = 0.0377). Gender also had a significant effect on canal visibility, where females had lower visibility than males overall (p = 0.0178) and had the most pronounced difference for PM1 (p = 0.0054). Location had a significant effect on visibility, but it differed by age and by gender: for age 65+, M2 had lower visibility than PM1 (p = 0.0411) and PM2 (p = 0.0180), while for females, PM1 had lower visibility than M1 (p = 0.0123) and M2 (p = 0.0419). Conclusions: The MC was visualized only in just over half of the CBCT images. Age, gender and location had significant effects on the visibility. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the anatomical variations of the mandibular canal through assessment in situ, panoramic radiography, CT or CBCT and assess their frequency. Methods: Articles were selected from databases (Cochrane Library, LILACS, ProQuest, PubMed, Scopus, Web of Science and Google Scholar), articles without limitations of language, in which the main objective was to evaluate the frequency of bifurcation of the mandibular canal through assessment in situ, panoramic radiography, CT or CBCT were selected. A meta-analysis of prevalence using random effects was performed. Results: Using a selection process in two phases, 15 articles were identified, and a meta-analysis was conducted. The results from these meta-analyses showed that the overall prevalence of anatomical variations for in situ studies was 6.46%, and through assessment of panoramic radiography and CT or CBCT the overall prevalence shown was 4.20% and 16.25%, respectively. Conclusions: There are two types of variations of the mandibular canal: the retromolar canal and bifid mandibular canal. The frequency variations through assessing in situ, panoramic radiography and CT or CBCT were 6.46%, 4.20% and 16.25%, respectively. [ABSTRACT FROM AUTHOR]

Disc fracture of the temporomandibular joint (TMJ) is a little-known pathological condition owing to its extreme rarity. We report two cases of elderly patients who were diagnosed with disc fracture of the TMJ based on MRI, and we review related reports. On physical examination, an incomplete bite and mild joint pain were observed on the affected side in both patients. An MRI showed a complete fracture in the intermediate zone of the articular disc in the TMJ; the posterior fragment was displaced posteriorly, causing occlusal change in the closed position of the condyle and an incomplete bite. Conservative treatment including manual manipulation, physical therapy and oral appliance had no effect on the occlusal abnormality. Although the inciting cause of the disc fracture remained unclear, the degenerative changes in the joint may have been a factor by increasing the brittleness and reducing the elasticity of the disc. [ABSTRACT FROM AUTHOR]

A radiographic examination of mandibular third molars is meant to support the surgeon in establishing a treatment plan. For years panoramic (PAN) imaging has been the first choice method; however, where an overprojection is observed between the third molar and the mandibular canal and when specific signs suggest a close contact between the molar and the canal, CBCT may be indicated. The present review provides an evaluation of the efficacy of CBCT for assessment of mandibular third molars using a six-tiered hierarchical model by Fryback and Thornbury in 1991. Levels 1-3 include studies on low evidence levels mainly regarding the technical capabilities of a radiographic method and the diagnostic accuracy of the related images. Levels 4-6 include studies on a higher level of evidence and assess the diagnostic impact of a radiographic method on the treatment of the patient in addition to the outcome for the patient and society including cost calculations. Only very few high-evidence studies on the efficacy of CBCT for radiographic examination of mandibular third molars exist and, in conclusion, periapical or PAN examination is sufficient in most cases before removal of mandibular third molars. However, CBCT may be suggested when one or more signs for a close contact between the tooth and the canal are present in the two-dimensional image--if it is believed that CBCT will change the treatment or the treatment outcome for the patient. Further research on high-evidence levels is needed. [ABSTRACT FROM AUTHOR]

Objectives: To assess the impact of spatial resolution and cone beam CT (CBCT) unit on CBCT images for the detection accuracy of condylar defects. Methods: 42 temporomandibular joints were scanned, respectively, with the CBCT units ProMax® 3D (Planmeca Oy, Helsinki, Finland) and DCT PRO (Vatech, Co., Ltd., Yongin-Si, Republic of Korea) at normal and high resolutions. Seven dentists evaluated all the test images with respect to the presence or the absence of condylar defects. Receiver operating characteristic curve analysis was employed to define the detection accuracy. Two-way analysis of variance was used to analyse the values under the receiver operating characteristic curves for the differences among imaging groups and observers. Intraobserver variation was analysed using the Wilcoxon test. Results: Macroscopic anatomy examination revealed that, of the 42 temporomandibular joint condylar surfaces, 18 were normal and 24 had defects on the surface of condyles. No significant differences were found between the images scanned with normal and high resolutions for both CBCT units ProMax 3D (p = 0.119) and DCT PRO (p = 0.740). Significant differences exist between image groups of DCT PRO and ProMax 3D (p < 0.05). Neither the inter- nor the intraobserver variability were significant. Conclusions: The spatial resolution per se did not have an impact on the detection accuracy of condylar defects. The detection accuracy of condylar defects highly depends on the CBCT unit used for examination. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the morphological condylar changes following orthognathic surgery by using a rapid and reliable computational method on panoramic radiographs. Methods: Digital panoramic radiographs of 45 patients who underwent bilateral sagittal split osteotomy (alone or associated with a Le Fort I osteotomy) between 2007 and 2010 were analysed. Calculation of the area, perimeter and height of 90 condyles was performed by using a specific computational method. Measurements were taken before surgery (m1), 1 day after surgery (m2) and 1 year after surgery (m3). The evolution of each index was analysed using paired t-tests between measures before and 1 day after surgery (m1 - m2) and measures before and 1 year after surgery (m1 - m3). The changes in the condylar area, perimeter and height were examined using the Bland and Altman plotting method. Results: There were no statistically significant changes in the mean condylar area, perimeter or height between m1 and m2 or between m1 and m3. The Bland and Altman plots for each index showed that a very limited number of condyles increased or decreased in area, perimeter and/or height outside the boundaries of the measurement error. Given the impossibility for a condyle to increase in size, these results are considered to represent the limits of the computational method used. Conclusions: This study demonstrated that there were no significant morphological condylar changes at the 1-year follow-up following surgery and that the range of normality in condylar changes could be influenced by the methodology used. [ABSTRACT FROM AUTHOR]

Objectives: To investigate and compare the detection accuracy of bony defects on the condylar surface of the temporomandibular joint (TMJ) in cone beam CT (CBCT) images scanned with standard and large view protocols on the same machine. Methods: 21 dry human skulls with 42 TMJs were scanned with the large view and standard view protocols of the CBCT scanner Promax 3D (Planmeca, Helsinki, Finland). Seven observers evaluated all the images for the presence or absence of defects on the surface of the condyle. Using the macroscopic examination of condylar defects as the gold standard, receiver operating characteristic (ROC) analysis was performed. Results: Macroscopic examination revealed that, of the 42 condyles, 18 were normal and 24 had a defect on the surface of the condyles. Areas under the ROC curves for the large view and the standard view group of CBCT images were 0.739 and 0.720, respectively, and no significant difference was found between the two groups of images (p = 0.902). Neither the interobserver nor the intraobserver variability were significant. Conclusions: The two scanning protocols provided by the CBCT scanner Promax 3D were reliable and comparable with detection of condylar defects. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to investigate characteristic MRI findings of rheumatoid arthritis (RA) in the temporomandibular joints (TMJs). Methods: 61 patients (122 TMJs) with RA in the TMJ and 50 patients (100 TMJs) with temporomandibular disorder (TMD) were included in this study. MR images of these patients were assessed by two oral radiologists for the presence or absence of osseous changes, disc displacement, joint effusion and synovial proliferation. These findings were compared between the two patient groups. Results: Osseous changes in the condyle and articular eminence/fossa in the RA patient group were significantly more frequent than in the TMD patient group, and were often very severe. Joint effusion was also significantly more frequent in the RA patient group. Synovial proliferation was found in all TMJs in the RA patient group, whereas it was very uncommon in the TMD patient group. Conclusions: Severe osseous changes in the condyle and synovial proliferation were considered characteristic MRI findings of RA in the TMJs. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to determine the potential of high-resolution ultrasonography for the detection of temporomandibular joint (TMJ) changes in children with juvenile idiopathic arthritis (JIA). Methods: We investigated prospectively 20 children (17 female and 3 male; mean age 11.06 years, standard deviation 3.43 years) with TMJ disorders caused by JIA, over a period of 16 months. Using a 12 MHz array transducer, four images in each TMJ (160 images) were acquired. Each image was analysed with regard to five different aspects (condylar erosion, thickness of the condylar disc, synovial thickness, joint effusion and enlargement of the intra-articular space). Results: Diagnosis of JIA was ensured for every child and involvement of the TMJ was proven by MRI. Overall 287 changes (35.9%) were detected by using high-resolution ultrasonography. On 124 images (77.5%) condylar erosions were diagnosed; on 55 images (34.4%) synovial thickness was abnormal; on 48 images (30%) we could see higher thickness of the condylar disc; on 40 images (25%) irregularities of the bony surface were detected; and on 20 images (12.5%) we found joint effusion. Conclusion: High-resolution ultrasonography could be a sufficient diagnostic method, especially for the detection of condylar involvement in children with JIA, even if not all parts of the TMJ are visible for ultrasonography. High-resolution ultrasonography is a valuable tool in particular situations: (i) when MRI examination is not available; (ii) when children fear MRI examination; (iii) in more advanced stages of JIA; and (iv) for monitoring the progression of TMJ involvement and response of therapy. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to examine the relationship between the roof of the glenoid fossa (RGF) thickness and condyle morphology and the influence of the number of remaining teeth and age. Methods: Cone beam CT data sets from 77 asymptomatic European patients were analysed retrospectively in this study. The thinnest area of RGF was identified among the sagittal and coronal slices on a computer screen; distance measurement software was used to measure the thickness. Moreover, we applied a free digital imaging and communications in medicine viewer for classification of condyle head type. It was also used to analyse any relation between RGF thickness and the number of remaining teeth. We performed a correlation analysis for RGF, age and missing teeth. Finally, we investigated combining sagittal condyle morphological characterization with coronal condyle morphology in relation to the number of joints and RGF thickness. Results: The Kruskal-Wallis test revealed no significant differences in RGF thickness among any of the coronal condyle head morphology groups (p > 0.05). There were significant differences in the thinnest part of RGF in relation to the sagittal plane for condyle morphological characterization, because we observed increased RGF thickness in joints with osteoarthritis features (p < 0.05). There is a non-significant correlation between the thinnest part of the RGF and the number of remaining teeth (/2 > 0.05). Conclusions: We found that the RGF thickness is unaffected by the coronal condyle head morphology and the number of remaining teeth. Osteoarthritic changes (sagittal condyle morphology) have an effect on RGF. [ABSTRACT FROM AUTHOR]

Objectives: To determine whether disc displacement (DD) can be a factor causing changes in condylar position in the glenoid fossa, using limited cone beam CT (LCBCT) images taken in the same time period as MRI that verified DD. Methods: The study included 60 joints in 57 male and female subjects aged 12-20 years (mean age 14.8 years). Subjects fulfilling the inclusion criteria were enrolled from a pool of post-orthodontic patients, and divided into four groups according to their disc status confirmed by MRI: partial DD (PDD), total DD with reduction (TDDWR), lateral DD (LDD) and medial DD (MDD). Changes in joint space from previously reported norms were measured on LCBCT images. Results: In PDD, the condyles were displaced posteriorly in the fossae with a mean anterior space of 2.7 ± 0.5 mm (normal 1.3 +_ 0.2 ram) and a posterior space of 1.8 ± 0.4 mm (normal 2.1 ± 0.3 mm). In TDDWR, the condyles were displaced not only posteriorly as observed in PDD, but also vertically with a reduced superior space of 1.9 ± 0.4 mm (normal 2.5 ± 0.5 mm). In LDD, the lateral space was significantly increased to 2.5 ± 0.3 mm (normal 1.8 ± 0.4 mm), while central and medial spaces were significantly decreased to 2.2 ± 0.5 mm (normal 2.7 ± 0.5 ram) and 1.7 ± 0.4 mm (normal 2.4 ± 0.5 ram), respectively. In MDD, the medial space was increased and the lateral and central spaces were significantly decreased. Conclusions" These results indicate that DD in adolescents and young adults can cause the condyle to change its position in the fossa with alterations in joint space which depend on the direction and extent of DD. [ABSTRACT FROM AUTHOR]

Objectives: Conventional panoramic radiography, a widely used radiographic examination tool in implant treatment planning, allows evaluation of the available bone height before inserting posterior mandibular implants. Image distortion and vertical magnification due to projection geometry is well described for rotational panoramic radiographs. To assess the accuracy of vertical height measurements on direct digital panoramic radiographs, implants and metal balls positioned in the posterior mandible were used as radio-opaque reference objects. The reproducibility of the measuring method was assessed by the inter- and intraobserver agreements. Methods: Direct digital panoramic radiographs, performed using a Kodak 8000C (Eastman Kodak Company, Rochester, NY), of 17 partially edentulous patients (10 females, 7 males, mean age 65 years) were selected from an X-ray database gathered during routine clinical evaluation of implant sites. Proprietary software and a mouse-driven calliper were used to measure the radiological length of 25 implants and 18 metal reference balls, positioned in mandibular posterior segments. The distortion ratio (DR) was calculated by dividing the radiological implant length by the implant's real length and the radiological ball height by the ball's real height. Results: Mean vertical DR was 0.99 for implants and 0.97 for balls, and was unrelated to mandibular sites, side, age, gender or observer. Inter- and intraobserver agreements were acceptable for both reference objects. Conclusions: Vertical measurements had acceptable accuracy and reproducibility when a software-based calibrated measurement tool was used, confirming that digital panoramic radiography can be reliably utilized to determine the pre-operative implant length in premolar and molar mandibular segments. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the study was to establish the changes in posteroanterior cephalometric variables in subjects with temporomandibular joint disorders (TMDs). Methods: Posteroanterior cephalograms of 61 subjects (age range 16-36.6 years, standard deviation 4.88 years) were used to determine cephalometric differences. Subjects were classified according to the Research Diagnostic Criteria for Temporomandibular Joint Disorders into three groups: unilateral TMD, bilateral TMD and no TMD. 14 linear and angular measurements were assessed on the posteroanterior cephalogram. For assessing facial asymmetry, the asymmetry index for bilateral measurements was calculated between the right and the left side. In cases with unilateral TMD, the asymmetry index was calculated using the difference between the unaffected and affected side. The differences among multiple groups were analysed using the one-way analysis of variance test and Scheffé post hoc test. Results: 47 subjects were females (77%) and 14 were males (23%). 19 subjects had unilateral TMDs and 16 subjects had bilateral TMDs. The asymmetry index of the distance from the horizontal plane to the antegonion was higher in subjects with unilateral TMD than in patients with bilateral or no TMD (p < 0.05). Also, the asymmetry index of the distances from the vertical plane to the condyle (p = 0.05), gonion (Go) (p = 0.0004), antegonion (p = 0.002) and chin (Ch) (p = 0.02) was higher in subjects with unilateral TMDs. The asymmetry index of the O point-Go-Go' and O point-Ch-Ch' angles differed significantly in subjects with unilateral TMDs (p < 0.05). Conclusions: Unilateral TMDs are associated with changes in posteroanterior cephalometric measurements. The assessment of posteroanterior cephalometric variables could be used as a key factor for evaluating the presence of TMDs. [ABSTRACT FROM AUTHOR]

Bifid mandibular condyles (BMCs) are rare anomalies. The overwhelming majority of prior reports described their predominantly unilateral occurrence diagnosed by panoramic radiography. We present an even rarer case of bilateral BMC initially identified by panoramic radiography and confirmed with colour-enhanced three-dimensional CT. These images substantiate the theory that the secondary condyles arise from the neck of the mandible (Lopez-Lopez et al. Bifid condyle: review of the literature of the last 10 years and report of two cases. [ABSTRACT FROM AUTHOR]

A rare case of aplasia of mandibular condyle associated with some other orthopaedic problems is presented. A 5-year-old boy attended our clinic with a chief complaint of facial asymmetry and chewing difficulty. The mandible was deviated to the left. The occlusion also showed a deflection to the left of the mandibular midline. He also had walking difficulty owing to a hip abnormality. Panoramic radiographic examination of the patient revealed that the left mandibular condyl was totally absent. The right condyle was unremarkable. His history revealed neither trauma nor any significant disease. Aplasia is a rare anomaly and means the insufficient development of the mandibular condyle. True agnesis of the mandibular condyle is extremely rare. Association of the manifestations of the patient with some orthopaedic problems makes this case interesting. [ABSTRACT FROM AUTHOR]

The incidence of tuberculosis (TB) is increasing worldwide and so are its consequences. Its oral manifestations are infrequent, occurring in approximately 3% of all cases. Although the primary lesion occurs as a pulmonary infection, the extrapulmonary infections have also shown an increase over the past few years. These infections generally involve the head and neck through haematogenous or lymphatic routes. The clinical presentation may be as an ulcer, granuloma, orofacial TB, TB of the salivary glands or tuberculous lymphadenitis. Rarely, secondary oral manifestations associated with pulmonary infection are seen, which can appear as lesions on the gingiva, palate, lips, tongue, buccal mucosa, frenulum and in the jaw bones. Owing to the rarity of orofacial TB, it seldom arouses clinical suspicion, especially when a positive history of a systemic infection or therapy is denied. Tuberculous involvement of the mandibular condyle is even rarer, and only two such cases are reported so far, both in English-language literature. Further, the diagnosis of such a case is extremely difficult as there are no specific signs pathogonomic of infection. The only manifestation may be a localized painful swelling of the jaw. The presented case is of osteomyelitis of the mandibular condyle in a 20-year-old male patient in whom TB was later suspected. In this case report the role of diagnostic techniques is emphasized as the osteomyelitis of the condyle has the risk of being easily missed owing to its atypical signs and symptoms and atypical radiographic appearance. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to assess bone changes and mobility in temporomandibular joints (TMJs) using cone beam CT (CBCT) in a population sample in Recife, PE, Brazil. Methods: The TMJ images of patients treated by a radiologist at a private dental radiology service over a period of 1 year were retrieved from the computer database and assessed using a computer with a 21-inch monitor and the iCAT Cone Beam 3D Dental Imaging System Workstation program (Imaging Sciences International, Hatfield, PA). The Pearson χ² test was used to analyse the differences in percentage of bone changes among the categories of mobility (p ≤ 0.05). The McNemar test was used to compare the presence of bone changes in TMJs on the right and left sides (p ≤ 0.05). Results: An adjusted logistic regression model was used to assess the effect of age and gender on the occurrence of bone changes (p ≤ 0.05). Bone changes were present in 227 (71%) patients. Age group and gender showed a statistically significant association with presence of bone changes (p ≤ 0.05). There was no significant difference between the right and left sides (p = 0.556) and in condylar mobility (p = 0.925) with regard to the presence of degenerative bone changes. Conclusions: There is a high prevalence of degenerative bone alteration in TMJs, which is more frequent in women and mostly located in the condyle. The prevalence of degenerative bone changes increases with age. There is no correlation between condylar mobility and the presence of degenerative bony changes in TMJs. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the patient demographic and CT imaging findings of primary osteosarcoma of the jaws. Methods: 88 primary osteosarcomas of the jaws histopathologically diagnosed during 1997-2007 were reviewed. 21 cases of CT images were reviewed. Results: Of 88 patients, 51 (58%) had tumours in the mandible and 37 (42%) in the maxilla. The mean age was 37.8 years (range 9-80 years). The male-to-female ratio was 1.32:1. The mean age of patients with mandibular lesions was 41.04 years and in those with maxillary lesions it was 33.3 years. CT imaging findings were available in 21 patients. In the maxilla (n = 9), all tumours (100%) arose from the alveolar ridge. In the mandible (n = 12), most tumours (9 cases, 75%), arose from the ramus and/or condyle. All except two lesions had the epicentrum within the medullary cavity of the involved bone. The presence of periosteal reaction was demonstrated in 13 cases (62%). Soft-tissue extension was present in 18 lesions (86%), with calcification identified in 13 (72%). Conclusions: This study provides age, sex distribution, location and CT imaging features of primary osteosarcoma of the jaws. [ABSTRACT FROM AUTHOR]

Morphological changes such as bifid and trifid mandibular condyle are rare entities. The aim of the present report is to describe a unique morphological variation of the mandibular condyle which has four separate condylar heads (tetrafid mandibular condyle) and to discuss clinical and radiological differential diagnosis of tetrafid mandibular condyle with advanced imaging techniques. [ABSTRACT FROM AUTHOR]

Objectives: This study was performed in order to verify bifid mandibular canals revealed from panoramic radiographic results. Methods: 1000 panoramic radiographs from dental patients and the panorama, cone beam CT (CBCT) and micro-CT from 40 dry mandibles were examined for bifid mandibular canals. The results were confirmed by a stereoscopic and histological examination of the cross-sectioned mandibles. Results: The prevalence of bifid canals detected from the panoramic radiographs was 0.038. The panoramic radiographs from one dry mandible showed two separate radiolucent mandibular canal-like structures delineated by radio-opaque lines. However, a stereoscopic and histological examination of a cross-section of the mandible showed that only one canal was a true canal containing neurovascular bundles: the other was false, reflecting merely a bony trabecular pattern. Conclusions: The presence of bifid mandibular canals determined by panoramic radiography should be judged with great caution in relation to dental surgery. [ABSTRACT FROM AUTHOR]

Objectives: The radiological evaluation of the temporomandibular joint (TMJ) consists of demonstrating the morphological features of the disc and the condyle in closed and open mouth positions using MRI. We aimed to determine elasticity of the disc by measuring the amount of elongation during mouth opening. Methods: The study population included 49 patients. Coronal T1 and multiplane oblique T2, weighted gradient recalled echo sequences were acquired in open and closed mouth positions. Biconcave TMJ disc lengths were measured on sagittal oblique images in both positions. Elongation ratio (ER) was calculated for each patient. According to the findings, TMJs are classified into subgroups: normal (N), dislocated with reduction (DWR), pure DWR (p-DWR), DWR with additional findings (DWR-a) and dislocated without reduction (DWOR). Statistical analysis was performed using the χ² test and receiver operating characteristic analysis. Results: Out of 98 discs, 22 of them were evaluated as N, 60 as DWR (28 p-DWR, 32 DWR-a) and 16 as DWOR. There was no significant difference among the disc lengths in three subgroups at the closed mouth position (P = 0.15), whereas there was significant difference in the open mouth position (P = 0.0001). There was significant difference among subgroups as far as ER is concerned (P < 0.05). Conclusions: ER is a strong indicator of elasticity. Compared with the N group, elasticity of the disc was not significantly different in the p-DWR group but the disc elasticity was very degraded in DWR-a and in DWOR. A negative conversion or one smaller than 1.4 mm means a compromised disc, although sometimes it will possess normal anatomical configurations or signal characteristics. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the reliability of a computational method for assessing three condylar measurements on digital panoramic radiographs: condylar height, area and perimeter. Methods: A computer calculation of the area, the perimeter and the height of 34 condyles was determined on digital panoramic radiographs taken from 17 patients. The test-retest precision of measurements calculation was estimated using an intraclass correlation coefficient (ICC) and Dahlberg's formula at 2 week intervals on the same radiograph to assess intraobserver precision and on two radiographs (RX1 and RX2) to assess the radiographic procedure precision. Changes between measurements on RX1 and RX2 were estimated using paired t-tests to detect systematic errors. Results: Precision of all indices was very high when measurements were made on the same radiograph, thus confirming good reliability for the present computational measuring method. The precision was lower when two different radiographs were compared but was still within an acceptable range of tolerance. There were no statistically significant changes in condylar area, perimeter or height values between RXI and RX2. Conclusions: This study has demonstrated that (1) the height of the condyle can be rapidly and reliably assessed using a specific computer system directly on digital panoramic radiographs: (2) although less reliable, area and perimeter can also be acceptably evaluated; and (3) this method has the potential for being routinely used to monitor changes in clinical follow-up as well as for research purposes. [ABSTRACT FROM AUTHOR]

We report the case of a woman who had secondary chondrosarcoma in an osteochondroma in the left mandibular condyle, presenting as a large lobulated bone density mass in the left condyle process, to illustrate the clinical characteristics and imaging findings. [ABSTRACT FROM AUTHOR]

Objective: With cone beam CT (CBCT) as the reference standard, the objective of this study was to determine the diagnostic accuracy of MRI for assessing osseous abnormalities of the temporomandibular joint (TMJ). Methods: 106 TMJs from 55 patients with temporomandibular disorder were examined by CBCT and MRI. CBCT images were evaluated by two experienced oral radiologists with regard to the presence or absence of each of the following eight types of osseous abnormalities: Type 1, destructive and erosive osseous changes of the condyle; Type 2, flattening of the articular surface of the condyle; Type 3, deformity of the condyle; Type 4, sclerosis of the condyle; Type 5, osteophyte formation; Type 6, ankylosis; Type 7, erosion of the articular fossa and/or eminence; and Type 8, sclerosis of the articular fossa and/or eminence. For detection of these osseous abnormalities by MRI, proton density-weighted images and T2 weighted images were evaluated independently by three observers. Using CBCT findings as the reference standard, the diagnostic performance of MRI for detecting various types of osseous abnormalities was evaluated by calculating its sensitivity and specificity. Results: Out of 106 joints, CBCT revealed Types 1, 2, 3, 4, 5, 6, 7 and 8 abnormalities in 25, 19, 26, 20, 14, 5, 19 and 22 joints, respectively. The mean sensitivities ofMRI among the three observers for detecting Types 1, 2, 3, 4, 5, 6, 7 and 8 abnormalities were 61%, 30%, 82%, 40%, 48%, 34%, 61% and 41%, respectively, whereas the mean specificities were 86%, 92%, 91%, 95%, 84%, 98%, 89% and 91%, respectively. Conclusions: Although high specificity (84-98%) was obtained with MRI, this modality showed relatively low sensitivity (30-82%) for detecting osseous abnormalities of the TMJ. The value of MRI for the detection of TMJ osseous abnormalities is considered to be limited. [ABSTRACT FROM AUTHOR]

Objectives: For surgical procedures involving the posterior mandible, it is important to be familiar with the details of the bifid mandibular canal. To our knowledge, there have been no systematic studies evaluating the bifid mandibular canal using sectional imaging. The purpose of this study is to evaluate the incidence and configuration of the bifid mandibular canal using cone beam CT. Methods: 252 patients (301 mandible sides) underwent cone beam CT between October 2004 and September 2005 and were included in this study. The cone beam CT images were evaluated for the presence and configuration of the bifid mandibular canal. The patterns of bifurcation were classified into four types according to the classification of Northé et al (Variations in the normal anatomy of the inferior dental (mandibular) canal: a retrospective study of panoramic radiographs from 3612 routine dental patients. Br J Oral Surg 1977; 15: 55-63). The diameter of the accessory canal was classified into two categories: 50% or more and less than 50% of the diameter of the main mandibular canal. Results: Of the 301 subjects, 47 (15.6%) demonstrated a bifid mandibular canal. They were Type I in 2, Type II in 40, Type III in 0, and Type IV in 5 cases. The diameter of the accessory canal was greater than or equal to 50% of the main canal in 23, and less than 50% in 24 cases. Conclusions: On the basis of the cone beam CT, a bifid mandibular canal was found in 15.6% of cases, a markedly higher proportion than found in previous reports using panoramic images. Cone beam CT is considered a suitable modality for detailed evaluation of bifid mandibular canals. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to investigate the frequency and pattern of bifid mandibular condyles (BMCs). Methods: A retrospective study was performed using panoramic radiographs from 10 200 patients undergoing dental treatment in the Department of Oral and Maxillofacial Radiology (Erzurum, Turkey) between 1996 and 2008. Results: Of the 10 200 patients, 32 (0.3%) had BMCs, of whom 17 were female (53.1%) and 15 were male (46.9%). The age range of the patients with BMCs was 5 to 71 years (mean age 30.0±0.40). Of these 32 patients, 24 (75.0%) had unilateral and 8 (25.0%) had bilateral BMCs, none of the patients had a history of trauma. No symptoms associated with bifid condyles were observed in any of the patients with BMCs. Conclusions: It is possible that BMC is a more frequent condition than is commonly perceived. However, because of the minimal symptoms associated with this condition, the authors believe that it will remain an incidental finding upon routine radiographic examination, rather than a clinical observation. Nevertheless, in symptomatic cases or in cases where surgical treatment is planned, panoramic radiographs should be supplemented with CT. [ABSTRACT FROM AUTHOR]

This report presents a case of osseous choristoma in the submandibular region of a 33-year-old female. Her chief complaint was painless swelling in the submandibular region. Panoramic radiography showed a well-defined, round, radiopaque lesion near the inferior border of the right mandibular angle. Coronal and sagittal tomographic images indicated a high-density area in the right submandibular region with no bony connection. The lesion was diagnosed as an osseous choristoma based on histopathological examination of the surgical specimen. A 1-year follow-up period was uneventful. [ABSTRACT FROM AUTHOR]

Objectives: Our aim was to investigate the diagnostic accuracy of in vivo micro-CT for osseous abnormalities of the rat temporomandibular joint (TMJ) condyle, using macroscopic observations as the ''gold standard''. Methods: A 30 TMJ arthritis model was prepared by injecting inflammatory complete Freund's adjuvant (CFA) into one side of the TMJ cavities of rats. The TMJ condyles were then imaged using micro-CT. The samples were macroscopically evaluated for osseous abnormalities, including erosions, osteophytes, flattening and concavity. The micro-CT images were independently assessed for abnormalities using the same criteria. Images in three planes were produced using the micro-XYZ technique with the micro-CT equipment. Results: According to the macroscopic observations, 26 of the 60 rat condyles showed osseous abnormalities. The micro-XYZ images detected abnormalities in 25 of the condyles. The condyle diagnostic accuracy of micro-CT was 0.98, the sensitivity was 0.96 and the specificity was 1.0. Conclusions: Good diagnostic results were obtained using micro-CT. It is therefore an effective technique for the evaluation of osseous abnormalities in the rat TMJ condyle. [ABSTRACT FROM AUTHOR]

Objectives: To compare the signal intensity (SI) of mandibular condyle bone marrow (MCBM) and the temporomandibular joint (TMJ) disc in patients with chronic anaemia and healthy subjects, and to investigate the relationships between bone marrow changes, age, types of anaemia and severity of anaemia. Methods: MRIs of 18 patients with chronic anaemia were compared with those of 12 healthy subjects. The SI ofMCBM and the TMJ disc were quantitatively evaluated. The SI of the grey matter (GM), white matter (WM) and the lateral pterygoid muscle were also investigated. Relationships between age, MCBM and TMJ disc signal-intensities and anaemia severity, and correlations between the groups, were analysed. Results: The mean MCBM SI was lower in anaemia patients (including both subgroups and also separately) than in healthy subjects (P < 0.05). No statistical significance was found for GM, WM and the muscle SI between the anaemia patients and healthy patient group (P > 0.05). No statistical significance was found between the groups with respect to the anterior band, whereas the mean SI value of the posterior band in the study group was significantly lower than in healthy subjects (P < 0.05). There were no correlations between age and MCBM SI, or between anaemia severity and MCBM SI. Conclusions: Anaemia may cause bone marrow alterations without any internal derangement. Patients with chronic anaemia exhibit lower mandibular condyle bone marrow and posterior band SI than healthy subjects. [ABSTRACT FROM AUTHOR]

Objectives: Bifid mandibular condyle (BMC) with associated temporomandibular joint ankylosis (TMJA) is extremely rare with only four cases reported. We present the first case series of BMC with TMJA in an attempt to elucidate the morphological pattern in this rare condition. Methods: Retrospective examination of CTs over a period of 6 years revealed 37 patients with TMJA, of whom 10 had BMC. Clinical and CT features of these were analysed. Patients were grouped according to sides of involvement and orientation of condyles. Results: The male:female ratio was 1:1. Nine were post-traumatic and one post-infectious. The aetiology was sustained in childhood in all patients. Six patients had unilateral BMCs and four had bilateral. One patient had bilateral BMCs with bilateral TMJA. This was anteroposterior (AP) in orientation. Three patients had bilateral BMCs with unilateral TMJA, among which one was AP and two mediolateral (ML). Six patients had unilateral BMC with ipsilateral TMJA; all of the ML anterior condylar process was ankylosed in joints with AP BMC and TMJA. Lateral condylar process was ankylosed in post-traumatic ML BMC with TMJA, while the medial condylar process ankylosed in the post-infectious patient. In general, ankylosed heads were found to be larger, sclerotic and often mushroom shaped compared with non-ankylosed heads. Conclusions: This series attempts to elucidate patterns of ankylosis and CT morphology in BMC with associated TMJA. Also included are hitherto unreported cases such as bilateral AP BMC with TMJA and post-infectious BMC with TMJA. [ABSTRACT FROM AUTHOR]

Gas in the joint space was observed in three patients with condylar fracture who were referred for CT examinations of the mandible. CT showed that the condylar fractures were non-open fractures. The gas was only observed in the intrajoint capsule of the temporomandibular joint (TMJ). Follow-up CT, 4 days after the initial CT, showed that the gas in the joint space was absorbed in one of three cases. In the non-open condylar fractures, the gas collection in the TMJ was considered to be a vacuum phenomenon due to the intact joint capsule of the TMJ on CT. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to confirm the radiographic morphology of mandibular condyles with microscopic observation and to investigate the mechanism of osseous changes of adult human mandibular condyles. Methods: Following the radiographic examinations of ten temporomandibular joints (TMJs) from five cadavers using conventional tomography, helical CT and limited cone beam CT for dentistry (limited CBCT), ten mandibular condyles were removed. Micro CT images were made of the undecalcified dissected joints in the sagittal plane, perpendicular to the long axis of the condyles, to produce images similar in orientation to the radiographic images. Tissue morphology was observed through backscattered electron images and elemental analysis using electron probe microanalysis (EPMA). The microscopic findings were compared with the radiographic findings. Results: Limited CBCT images most accurately depicted erosive change of the bone cortex of the mandibular condyle. EPMA indicated bone remodelling in all mandibular condyles analysed, which showed cartilage calcification different from typical enchondral ossification. No finding of dissolution or disruption of the superficial soft tissue was observed in all specimens, including those presenting radiographic findings of osteoarthrosis. Active bone remodelling with hypertrophic changes of superficial soft tissue was observed in mandibular condyles, which implied radiographic findings of osteoarthrosis. Conclusions: The high detectability of limited CBCT images on bony morphology of mandibular condyles was confirmed. It is speculated that bone remodelling of adult human mandibular condyles is brought about by cartilage calcification. It was suggested that the osseous changes classified as osteoarthrosis with radiographic images are normal bone remodelling. [ABSTRACT FROM AUTHOR]

Objectives: To assess the accuracy of NewTom 9000 cone beam CT (CBCT) images for the detection and quantification of periodontal bone defects in three dimensions. Methods: A sample of 146 sites in 5 dry skulls provided the ground truth (GT). Half of the sample had bone loss of at least 3 mm. Two metal spheres at each site ensured correspondence between GT and CBCT measurements. Skulls were submerged in water and scanned with the NewTom QR-DVT-9000. A full mouth series (FMX) was obtained of each skull using photostimulable phosphor plates. Six observers measured the bone height of each site and rated the presence or absence of bone loss. Measurements were compared to GT and Az-values were calculated from receiver operating characteristic curves. Results: The Az-value for CBCT was 0.74 (standard deviation (SD)=0.14) and for FMX 0.48 (SD=0.09). The difference was significant (ANOVA: P < 0.01). The diagnostic accuracy of CBCT was lower for anterior teeth (Az=0.59) than for molars (Az=0.82) and premolars (Az=0.79) (Tukey's HSD (honestly significant difference): P < 0.01). The mean absolute difference between CBCT and GT was 1.27 mm (SD=1.43) and between FMX and GT 1.49 mm (SE=1.24) (ANOVA: P < 0.01). Measurements in the anterior mandible were less accurate than in other areas (Tukey's HSD: P < 0.01). Conclusion: The NewTom 9000 cone beam CT scanner provides better diagnostic and quantitative information on periodontal bone levels in three dimensions than conventional radiography. The accuracy in the anterior aspect of the jaws is limited. [ABSTRACT FROM AUTHOR]