Adriana Dibo Cruz

Relationship between bone mineral density and trabecular bone pattern in postmenopausal osteoporotic Brazilian women

ObjectivesThe aim of this study is to evaluate the relative efficacy of the mandibular trabecular bone in detecting osteoporotic-associated bone changes in Brazilian women.Materials and methodsSeventy-three digital panoramic radiographs of healthy and osteoporotic postmenopausal women were used. Regions of interest were selected in the mandibular angle and body of the panoramic images, which were analyzed for fractal dimension (FD) and pixel intensity (PI). Statistical analysis evaluated the distribution pattern, compared normal with osteoporotic patients and the right with the left mandible, and assessed the relationship between FD and PI. The significance level was set at 0.05.ResultsFD and PI values were significantly different (p < 0.05) between normal and osteoporotic patients for the right and left mandibular angle and for the left mandibular body. There was no significant difference (p > 0.05) between the right and left mandibular angle for FD and PI, but a significant difference (p < 0.05) was observed on the mandibular body for PI values. FD and PI values presented positive correlation.ConclusionsThe mandibular trabecular bone was effective in detecting osteoporotic changes, with the exception of the right mandibular body.Clinical relevanceMandibular trabecular bone shows a promising attempt of accurate detection of osteoporotic changes in some regions of the jaws. Fractal analysis and pixel intensity had strong positive correlation.

Prevalence and characteristics of pneumatization of the temporal bone evaluated by cone beam computed tomography.

The aim of this study was to determine the prevalence and characteristics of pneumatization of the glenoid fossa and articular eminence by means of cone beam computed tomography (CBCT) images. CBCT images of 658 patients (1316 joints) were evaluated to determine pneumatization in the articular eminence (PAT) and roof of the glenoid fossa (PGF). Age and gender were recorded for all patients and, for the cases of pneumatization, laterality and type (unilocular or multilocular) were noted. Its prevalence was correlated with gender, age and laterality by statistical analyses. 21.3% of individuals presented with PAT and 38.3% presented with PGF. Considering the temporomandibular joint, PAT was in 15.5% and PGF in 30.2%. Of PAT cases, 54.3% were unilateral and 45.7% bilateral; 3.4% were unilocular and 96.6% were multilocular. In the PGF cases, 42.5% were unilateral and 57.5% bilateral; 0.02% was unilocular and 99.8% were multilocular. There was no statistical difference regarding gender and age; but there was statistical difference regarding laterality, with higher frequency on the left side. In conclusion, there was a significant prevalence of PAT and PGF in the studied population; their prevalence seems higher than has been previously supposed.

Lateral pterygoid muscle volume and migraine in patients with temporomandibular disorders

Purpose Lateral pterygoid muscle (LPM) plays an important role in jaw movement and has been implicated in Temporomandibular disorders (TMDs). Migraine has been described as a common symptom in patients with TMDs and may be related to muscle hyperactivity. This study aimed to compare LPM volume in individuals with and without migraine, using segmentation of the LPM in magnetic resonance (MR) imaging of the TMJ. Materials and Methods Twenty patients with migraine and 20 volunteers without migraine underwent a clinical examination of the TMJ, according to the Research Diagnostic Criteria for TMDs. MR imaging was performed and the LPM was segmented using the ITK-SNAP 1.4.1 software, which calculates the volume of each segmented structure in voxels per cubic millimeter. The chi-squared test and the Fishers exact test were used to relate the TMD variables obtained from the MR images and clinical examinations to the presence of migraine. Logistic binary regression was used to determine the importance of each factor for predicting the presence of a migraine headache. Results Patients with TMDs and migraine tended to have hypertrophy of the LPM (58.7%). In addition, abnormal mandibular movements (61.2%) and disc displacement (70.0%) were found to be the most common signs in patients with TMDs and migraine. Conclusion In patients with TMDs and simultaneous migraine, the LPM tends to be hypertrophic. LPM segmentation on MR imaging may be an alternative method to study this muscle in such patients because the hypertrophic LPM is not always palpable.

Clinical and MRI investigation of temporomandibular joint in major depressed patients

OBJECTIVE The aim of the present study was to describe the clinical and MRI findings of the temporomandibular joint (TMJ) in patients with major depressive disorders (MDDs) of the non-psychotic type. METHODS 40 patients (80 TMJs) who were diagnosed as having MDDs were selected for this study. The clinical examination of the TMJs was conducted according to the research diagnostic criteria and temporomandibular disorders (TMDs). The MRIs were obtained bilaterally in each patient with axial, parasagittal and paracoronal sections within a real-time dynamic sequence. Two trained oral radiologists assessed all images. For statistical analyses, Fishers exact test and χ(2) test were applied (α = 0.05). RESULTS Migraine was reported in 52.5% of subjects. Considering disc position, statistically significant differences between opening patterns with and without alteration (p = 0.00) and between present and absent joint noises (p = 0.00) were found. Regarding muscular pain, patients with and without abnormalities in disc function and patients with and without abnormalities in disc position were not statistically significant (p = 0.42 and p = 0.40, respectively). Significant differences between mandibular pathway with and without abnormalities (p = 0.00) and between present and absent joint noises (p = 0.00) were observed. CONCLUSION Based on the preliminary results observed by clinical and MRI examination of the TMJ, no direct relationship could be determined between MDDs and TMDs.

Prevalence of C-shaped root canal in a Brazilian subpopulation: a cone-beam computed tomography analysis

The aim of this study was to use cone-beam computed tomography (CBCT) images to evaluate the prevalence and configurations of C-shaped canals in permanent mandibular second molars among members of a Brazilian subpopulation. CBCT exams of 214 patients (406 teeth) were evaluated for: presence of C-shaped root canals, number of canals and direction of the root grooves (buccal or lingual). Of the 214 CBCT images examined, 192 showed intact bilateral molars, which were used to analyze the distribution of unilateral and bilateral occurrences of C-shaped canals. The prevalence of these canals was correlated with gender and age, and the number of canals was correlated with the direction of the root grooves using the chi-squared test (α = 0.05). The prevalence of C-shaped canals was 15.3%. This prevalence did not differ with gender or age. Most of the C-shaped molars had three (43.5%) or two (37.1%)canals; 69.4% of the C-shaped canals were grooved in the buccal direction; 68.3% of the C-shaped cases were unilateral. In conclusion, there was a significant prevalence of C-shaped canals in the mandibular second molars of the population studied; the C-shaped canal system varied in configuration, with a higher prevalence of three and two canals and unilateral occurrence; CBCT is a useful tool for endodontic diagnosis and treatment.

Diagnosis of secondary caries in esthetic restorations: influence of the incidence vertical angle of the X-ray beam

The aim of this study was to evaluate the accuracy on the diagnosis of secondary caries-like lesions simulated on esthetic restorations of different materials, changing the incidence vertical angle (IVA) of the x-ray beam. Twenty human teeth received MOD inlay preparations. In the experimental group (n=10), a round cavity was made in the floor of the proximal box to simulate the caries-like lesion. All teeth were restored with 3 composite resins (Charisma, Filtek-Z250 and TPH-Spectrum) at 3 moments. Two radiographic images were acquired with 0º and 10º IVA. Ten observers evaluated the images using a 5-point confidence scale. Intra- and interobserver reliability was analyzed with the Interclass Correlation Coefficient and the diagnostic accuracy was evaluated using the area under the ROC curve (A(z)), Friedman test and Wilcoxon test (α=0.05). Higher accuracy values were obtained with 10º IVA (A(z)=0.66, Filtek-Z250>A(z)=0.56, TPH-Spectrum) compared to 0º (A(z)=0.55, Charisma>A(z)=0.37, TPH-Spectrum), though without statistically significant difference (p>0.05). The detection of secondary caries-like lesions simulated on esthetic restorations of different materials suffered no negative influence by changing the IVA of the x-ray beam.

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 appraisers response pattern was analyzed using the Kappa test (κ), and diagnostic tests were performed to assess each appraisers performance using a significance level setting of 5% (α = 0.05). Reliability of each appraisers 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.

Alternative X-ray filters for an intra-oral digital radiographic system

OBJECTIVE The aim of this study was to evaluate the effect of the modulation of the radiation spectrum with the use of alternative X-ray filters in the quality of intra-oral digital images from storage phosphor plates. METHODS The radiographic exposures were performed in a GE 1000 X-ray machine (General Electric Co., Milwaukee, WI), operating at 65 kVp, 10 mA, 40 cm focus receptor distance using three different exposure times: 0.05 s, 0.16 s and 0.35 s. The control filter (GC) was 100% aluminium (Al) with a thickness of 1.5 mm. The tested filters were: G1, 97% Al and 3% copper (Cu) with 1.47 mm thickness; G2, 96% Al and 4% Cu with 1.53 mm thickness; G3, 95% Al and 5% zinc (Zn) with 1.56 mm thickness; G4, 98% Al and 2% Zn with 1.5 mm thickness; and G5, 95% Cu and 5% Zn with 1.6 mm thickness. For formation of the image, a 12-step Al wedge (each step with increments of 1 mm in thickness) was radiographed 10 times. Pixel values measured in digital images were converted into optical density (OD). RESULTS All replicates showed OD with high reproducibility (r > 0.95) for all exposure times and tested filters. In comparison between filters, statistically significant differences in density (p < 0.05) were observed. The OD curve of the G5 filter in all exposure times and G3 filter in an exposure time of 0.05 s showed changes in shape (p < 0.05). CONCLUSIONS Excluding the G5 filter, all others tested filters can be used as a substitute for GC without losses in image quality.

Gray scale inversion in digital image for measurement of tooth length

The aim of this study was to assess the applicability of gray scale inversion in performing digital linear endodontic measurements. Standardized digital images were taken of 40 extracted human permanent single-rooted teeth with K-files size 15 placed at different lengths in the root canal, using the CDR Wireless(®) digital system. All images were treated with Positive, a digital tool that inverts the grayscale value. Eight radiologists measured the distance between the lower limit of the rubber stop and the tip of the file on both original and positive images. After 15 days, they repeated this procedure in 50% of the image samples. The intra- and inter-examiner agreement was analyzed by intraclass correlation test, and the comparison between the two image groups and the actual lengths by the Students t-test (α=0.05). Intra- and inter-examiner evaluation showed high reproducibility (r>0.95) of both original and positive images. No statistically significant differences (p>0.05) were found between measurements performed on original and positive images, but both differed significantly from the actual lengths (p<0.05). Gray scale inversion has low applicability in measuring endodontic files, since it did not improve the accuracy of measurements.

Condição de saúde oral e indicativos da síndrome de Burnout em estudantes de Odontologia sedentários e atletas

The study aimed to compare the oral health condition and the Burnout syndrome indicatives of athete and sedentary dental students. After the approval of the project by the research ethics committee a non-probabilistic sample of convenience, with students of third year of dentistry course of a Brazilian Federal University with similar characteristics in relation to sex, age, schooling and socioeconomic level were selected. They composed two independent groups: 1) Atheletes and 2) Sedentaries. For health estimations were performed a periodontal evaluation and data collections from a questionnaire on the basis of a validated tool, the Maslach Burnout Inventory-General Survey (MBI), a medical records and a panoramic radiograph. All data were statistically analyzed by T-test, Mann-Whitney test, simple logistic regression analysis and Pearsons correlation (significance at 5%, α = 0.05). There were variations in the oral health condition between the athelete and sedentary dental students for bleeding on probe, probe depth and radiographic findings that statistically differed (p<0.05) showing worst results for the sedentary group. The bleeding on probe was the main indicator of the discrepancy and presented a weak correlation (ρ = 0.31) with an emotional exhaustion, which measures feelings of being emotionally overextended and exhausted. Sedentary dental students are more sensitive to problems and tensions triggered in the academic environment with a greater propensity to instalation of somatic injuries such as oral problems.