Magnetic resonance imaging assessment of juvenile idiopathic arthritis using OMERACT and EuroTMjoint classifications.

This retrospective case-control study compared inflammatory and structural damage in the temporomandibular joint of patients with juvenile idiopathic arthritis (JIA) and its subtypes and healthy patients using the Outcome Measures in Rheumatology Clinical Trials (OMERACT) and EuroTMjoint classifications. Correlations between the scores of the two classifications and time of diagnosis were evaluated. Twenty-nine JIA patients and 48 age-matched healthy participants were examined. TMJ images on each side were considered individually. Oligoarticular and polyarticular subtypes were present in 44.8% and 55.2% of patients, respectively. The JIA group presented a higher frequency and more severe signs of inflammatory and structural changes (P < 0.05), except for effusion (P = 0.83). The polyarticular subtype showed a higher change intensity. The time of JIA diagnosis was not correlated with inflammatory and structural changes. Positive correlations between inflammation and bone deformity scores were observed for the EuroTMjoint classification (r = 0.462, P < 0.001; low correlation) and OMERACT classification (r = 0.737, P < 0.001; high correlation). Positive correlations between the OMERACT and EuroTMjoint classifications were found for inflammation score (r = 0.907, P < 0.001; very high correlation) and bone deformity score (r = 0.854, P < 0.001; high correlation). Both classifications showed a higher frequency and intensity of inflammation and bone deformity in JIA patients. The results of this study suggest that the appropriate management of inflammation may reduce the potential for structural damage to the TMJ.

Influence of exposure parameters on the detection of simulated root fractures in the presence of various intracanal materials.

AIM: To investigate how the exposure parameters used when producing CBCT scans affect diagnostic accuracy when detecting simulated vertical root fractures and how various filling materials affect image quality. METHODOLOGY: A total of 160 extracted single-rooted human teeth were divided into four groups based on the materials within the root canals: unrestored, gutta-percha, metallic post and fibreglass post. Half of the sample of each group was selected for the induction of vertical root fractures. Each tooth was placed in an empty socket of a dry skull which was scanned on a CBCT unit (9000 3D scanner; Kodak Dental Systems, Carestream Health, Rochester, NY, USA) using the following exposure parameters: 74 kV/12 mA; 74 kV/10 mA; 74 kV/8 mA; 74 kV/6.3 mA; 70 kV/12 mA; 70 kV/10 mA; 70 kV/8 mA; 70 kV/6.3 mA. Two observers assessed all images using a 5-point confidence scale for fracture detection and a 4-point score for the presence of artefacts. Sensitivity, specificity, accuracy and area under ROC curve were compared by two-way anova and Tukey's test. Artefact formation was evaluated by descriptive statistics. RESULTS: There were no significant differences in the sensitivity (P = 0.370), specificity (P = 0.660), accuracy (P = 0.084) and area under the ROC curve (P = 0.674) values amongst the various exposure parameters within the same group. There were some significant differences when the groups were compared for each intracanal material. The sensitivity and accuracy of the group containing metallic posts were significantly lower than the unrestored and fibreglass post groups (P ≤ 0.017). CONCLUSION: The variations in exposure parameters did not interfere with the diagnosis of vertical root fractures, independent of the root canal restorative status. Metallic posts were associated with greater artefact formation and compromised the diagnostic performance. It is possible to decrease the kVp/mA settings to reduce the probability of biological effects due to radiation, without losing diagnostic accuracy.

Correlation between temporomandibular joint morphology and disc displacement by MRI.

OBJECTIVES: The aim was to evaluate the morphology of the temporomandibular joint's (TMJs) disc and condyle as well as its correlation with disc displacement, using MRI. METHODS: 190 TMJs were retrospectively analysed. The condyle morphology of each TMJ was evaluated by two observers using both axial and coronal views, as were their disc morphology and displacement, using sagittal view. Condyle morphology was classified as flat, convex, angled or rounded in the coronal sections and as anterior side flat/posterior side convex, biconvex, anterior side concave/posterior side convex, flat or biconcave in the axial view. Disc morphology was determined as biconcave, biplanar, biconvex, hemiconvex or folded. χ2, Fisher exact and Bonferroni correction tests were used to evaluate the data. ANOVA followed by post hoc Tukey's test was used to evaluate the interaction between age and disc displacement. RESULTS: Anterior disc displacement with reduction; convex condyle morphology in the coronal view; anterior side concave/posterior side convex morphology in the axial view; and biconcave discs were found to be the most prevalent findings. An association was observed between disc morphology and disc displacement (p<0.001). No correlation between condyle morphology and TMJ disc displacement was found (p=0.291 for axial and p=0.14 for coronal views). CONCLUSIONS: The results of this study suggest that TMJ disc morphology is associated with disc displacement.

Magnetic resonance imaging findings of true bifid mandibular condyle with duplicated mandibular fossa.

Bifid mandibular condyle (BMC) is a rare asymptomatic morphological alteration with no predilection for age group or gender. Its morphology varies from a shallow groove to two condylar heads with separate necks, oriented mediolaterally or anteroposteriorly. This report describes an unusual case of anteroposterior bifid condyle in a 39-year-old female patient with the main complaint of mouth-opening limitation and a deviation of the mandible to the left side. Magnetic resonance imaging (MRI) findings revealed a bifid condyle on the left side and duplicated mandibular fossa, with the articular disc over the anterior head. The MRI images in the open-mouth position revealed minimal movement of the condyle. Despite the increased number of mediolateral bifid mandibular condyle cases described in the literature, none of previously reported cases of BMC included an anteroposterior bifid condyle case with two distinct mandibular fossa.

Effect of alternative photostimulable phosphor plates erasing times on subjective digital image quality.

OBJECTIVE: To evaluate the influence of alternative erasing times of DenOptix(R) (Dentsply/Gendex, Chicargo, IL) digital plates on subjective image quality and the probability of double exposure image not occurring. METHODS: Human teeth were X-rayed with phosphor plates using ten different erasing times. Two observers evaluated the images for subjective image quality (sharpness, brightness, contrast, enamel definition, dentin definition and dentin-enamel junction definition) and for the presence or absence of double exposure image. Spearman's correlation analysis and ANOVA was performed to verify the existence of a linear association between the subjective image quality parameters and the alternative erasing times. A contingency table was constructed to evaluate the agreement among the observers, and a binominal logistic regression was performed to verify the correlation between the erasing time and the probability of double exposure image not occurring. RESULTS: All 6 parameters of image quality were rated high by the examiners for the erasing times between 25 s and 130 s. The same erasing time range, from 25 to 130 s, was considered a safe erasing time interval, with no probability of a double exposure image occurring. CONCLUSIONS: The alternative erasing times from 25 s to 130 s showed high image quality and no probability of double image occurrence. Thus, it is possible to reduce the operating time of the DenOptix(R) digital system without jeopardizing the diagnostic task.

Hybrid lesion: central giant cell granuloma and benign fibro-osseous lesion.

Hybrid lesions comprise elements of different pathologies in one lesion. Hybrid lesions comprising central giant cell granulomas (CGCG) with fibro-osseous components are rare, with only six maxillomandibular cases reported in the literature. We report a case of a hybrid lesion in a 38-year-old woman who presented with a swelling in the mandibular parasymphysis, on the left side. Panoramic and occlusal radiographs and CT showed a mixed lesion with expansion of the buccal cortical plate that pointed to the diagnosis of ossifying fibroma (OF). Complete excision of the lesion was performed, and the anatomopathological examination showed features of both CGCG and a fibro-osseous lesion. Clinical, imaging and histopathological features indicate a hybrid lesion of CGCG and OF. The patient remains asymptomatic after 30 months of follow-up.

Benign cementoblastoma: case report and review of the literature.

Benign cementoblastoma (BC) is a relatively rare odontogenic neoplasm characterized by the formation of a mass of cementum-like tissue connected to the root of a tooth. Clinically, BC has a slow and constant growth pattern, frequently accompanied by pain, and it promotes volume expansion on both the vestibular and lingual surfaces. Radiographically, it appears attached to the apical or lateral portion of the root of a tooth root as a densely radiopaque, well-circumscribed mass surrounded by a thick and uniform radiolucent halo. Treatment usually consists of surgical tooth extraction along with the attached calcified mass or endodontic treatment of the associated tooth, enucleation of the tumor and osseous curettage. In this article, the clinical, radiographic and histopathological features of one case of BC are presented and the variations of the cases cited in the literature are discussed.

Determination of the length of zygomatic implants through computed tomography: establishing a protocol.

OBJECTIVES: The aim of this study was to establish and verify an examination protocol using CT to estimate the length of zygomatic implants, thus rendering the surgical process safer and more predictable, and exposing the patient to a minimal level of radiation. METHODS: Paracoronal CT scan was carried out on ten dry human crania (n = 20) and the zygomatic implant sites were measured (L(CT)) bilaterally. A standard surgical zygomatic implant placement procedure was carried out and the actual lengths (L(Real)) and clinical lengths (L(Clin)) determined. RESULTS: The averages of the L(CT), L(Clin) and L(Real) were 45.73 +/- 4.82 mm, 42.63 +/- 4.33 mm, and 44.73 +/- 4.53 mm, respectively. Student's t-test revealed no statistically significant differences between the L(Real) and L(CT) averages (P = 0.1532), whereas the L(Real) and L(Clin) averages were statistically different (P < 0.0001). CONCLUSIONS: The proposed protocol proved to be precise and efficacious in the determination of zygomatic implant length, with the advantage to the patient of a relatively low level of exposure to radiation due to the small quantity of tomographic slices used. Although there were no major repercussions, the clinical probe in the zygomatic implant kit commonly used in this surgical procedure proved to be a rather imprecise tool.

Analysis of magnetic resonance imaging characteristics and pain in temporomandibular joints with and without degenerative changes of the condyle.

The aim of this study was to investigate temporomandibular joint (TMJ) pain and magnetic resonance imaging characteristics in 104 TMJs with and 58 without degenerative changes of the condyle, such as osteophytes, erosion, avascular necrosis, subcondral cyst and intra-articular loose bodies. TMJ images were also assessed for flattening, retropositioning and hypomobility of condyle and disc displacement. Comparison of the TMJ side-related data showed a significant relationship between disc displacement without reduction (DDwoR) and the presence of degenerative bony changes (p=0.00). Flattening, retropositioning and hypomobility of condyle showed no significant difference in relation to the presence or absence of degenerative bony changes. Retropositioning of the condyle was significantly associated to disc displacement with reduction (DDwR) (p=0.00), while condylar hypomobility was significantly more frequent in TMJ with DDwoR (p<0.05). Independent of the presence or type of DD, TMJ pain was more frequent in the presence of degenerative bony changes. When considering only DDwR, TMJ pain was significantly associated to a degenerative condition (p=0.03). When there were no degenerative bony changes, TMJ pain was significantly more frequent in DDwoR (p=0.04). Despite the present findings, the absence of symptoms in some patients with condylar bony changes suggests that the diagnosis of osteoarthritis should be established by evaluation of magnetic resonance images in association with clinical examination.

Effectiveness of computed tomography to evaluate central giant cell lesion.

Central giant cell lesion (CGCL) is a benign disease involving the mandible (70%) more than the maxilla; it tends to be more common in women. Clinically, the lesion may be associated with pain, tooth displacement, facial asymmetry, paraesthesia and ulceration of the mucosa. The radiographic aspect of CGCL is highly variable since it may appear as a unilocular or multilocular radiolucent area with expansion and perforation of the cortical bone. Few previous reports have dealt with the usefulness of CT in the evaluation of this lesion. The purpose of this study is to report the clinical and imaging features of a case, including CT, treated by a conservative method.

Osteochondritis dissecans of the temporomandibular joint.

A case is reported of a 43-year-old female patient presenting bilateral osteochondritis dissecans (OCD) of the temporomandibular joint (TMJ), in different stages for each side, associated with avascular necrosis (AVN) of the right condyle. Additionally observed was anterior disk displacement without reduction for both sides. We have proposed an adaptation of the previous classification of OCD for cases affecting the TMJ. We have also stressed the fundamental role of panoramic radiography on the diagnosis of stage 3 and stage 4 OCD of the TMJ. In relation to MRI, we have recommended sagittal (slice thickness of 2 mm) and coronal (slice thickness of 1 mm) fast spin-echo proton density-weighted sequences to better identify bone lesions (stage 1 and 2) and also localize osteochondral loose bodies; and coronal (slice thickness of 1 mm) fat-suppressed fast spin-echo T2 weighted sequence to better evaluate OCD (stable or unstable) and the features of the occasionally associated AVN (acute or chronic).

Computed tomography for dental implants: the influence of the gantry angle and mandibular positioning on the bone height and width.

OBJECTIVES: To investigate the effect of deviation of mandibular positioning, by changing the gantry angle, on the measured height and width of dental implant sites in reformatted cross-sectional computed tomography (CT) scans. METHODS: CT images of ten human dry mandibles were made in three gantry positions to simulate changes in patient positioning: (1) parallel to the lower base of the mandible (standard); (2) with a gantry inclination of +19 degrees ; and (3) with an inclination of -19 degrees . One examiner measured the bone height and width at selected sites in the images at three different times. Results were compared with a paired test in SAS 8.02. RESULTS: In relation to bone height, when the jaws were inclined to the inferior direction (gantry angle +19 degrees ), there was no statistically significant difference for any region studied. There was a statistically significant difference for the incisor region when the jaws were inclined to the superior direction (gantry angle -19 degrees ). With respect to the width of the bone rim, there was a statistically significant difference only for the region of the molars when the jaw was inclined to the inferior direction and for the region of the canine, when the inclination was to the superior direction. CONCLUSIONS: Errors in mandibular positioning of 19 degrees produced image discrepancies with regard to bone height and width which were not excessive. Thus, examinations do not have to be repeated owing to variation of mandibular positioning because the differences were lower than 10% of the value found for the standard position.

Mandibular ramus-related Stafne's bone cavity.

Mandibular bone depressions located on the lingual/buccal aspect of the mandibular ramus are the rarest variants of the so-called Stafne's bone cavities, or major salivary gland-related depressions, with only 17 cases reported in the literature including both clinical cases and archaeological specimens. We report the case of a 14-year-old male patient who sought clinical assistance complaining of a hard expansion on the lower left premolar-molar region. Apart from a unilocular radiolucent lesion between the lower left second premolar and first molar, a panoramic radiograph showed another radiolucent lesion located in the right mandibular ramus, at the level of the mandibular foramen. Computed tomography (CT) revealed an expansile lesion in the left mandibular body, later diagnosed as a simple bone cyst through surgical exploration. The three-dimensional CT volume rendering reconstructed image showed that the second lesion, located on the lingual aspect of the ascending ramus, was an actual cortical bone defect, which was diagnosed as a mandibular ramus-related Stafne's bone cavity. Considering the young age of the patient, the size of the defect, the recognizedly slow development of mandibular bone defects and, above all, the location of the bone defect under discussion, we believe it to have a congenital rather than a developmental origin (i.e. it was caused by a focal failure during intramembranous ossification of the mandible). If this is the case, mandibular bone depressions should not be seen exclusively as salivary gland-related bone defects.