[Show abstract][Hide abstract] ABSTRACT: Introduction:
The proximity of the roots to the maxillary sinus can create a variety of risks.
To evaluate the relationship between the roots of healthy teeth and the maxillary sinus, as well as the occurrence of sinus pathologies.
Three radiologists analyzed 109 cone beam computed tomography (CBCT) images. The Kappa test was used to assess the intra- and inter-rater agreement. The chi-squared test and prevalence ratio were used to test the hypothesis that roots of healthy teeth in the maxillary sinus favored the occurrence of sinus pathologies (p=0.01).
Intra- and inter-rater agreement ranged from good to excellent. The chi-squared test demonstrated a statistically significant difference (p=0.006) between the tooth roots in diseased maxillary sinuses (6.09%) and those in normal sinuses (3.43%). The prevalence ratio test showed a statistically significant higher prevalence of tooth roots in diseased sinuses than in normal sinuses (p<0.0001). Roots in the maxillary sinus were 1.82 times more associated with diseased sinuses.
Dental roots in the maxillary sinus are almost twice as likely to be associated with diseased sinuses than normal sinuses. Healthy teeth whose roots are inside the maxillary sinus may induce an inflammatory response in the sinus membrane. It is suspected that dental procedures may exacerbate the condition.
Preview · Article · Jan 2016 · Brazilian journal of otorhinolaryngology
[Show abstract][Hide abstract] ABSTRACT: To assess the efficacy of lead foils in reducing the radiation dose received by different anatomical sites of the head and neck during periapical intraoral examinations performed with digital systems.
Images were acquired through four different manners: Phosphor plate (PSP) alone; PSP + lead foil; CMOS alone; and CMOS + lead foil. Radiation dose was measured after a full-mouth periapical series (14 radiographs) using the long cone paralleling technique was obtained. Lithium fluoride (Lif 100) thermoluminescent dosimeters were placed in an anthropomorphic phantom at points corresponding to the tongue, thyroid, the crystalline lenses, the parotid glands and the maxillary sinuses.
Dosimeter readings demonstrated the efficacy the addition of lead foil in the intraoral digital X-ray systems provided in reducing organ doses in the selected structures, approximately of 32% in the PSP system and 59% in the CMOS system.
The use of lead foils associated with digital X-ray sensors is an effective alternative for the protection of different anatomical sites of the head and neck during full-mouth periapical series acquisition.
No preview · Article · Jun 2015 · Dentomaxillofacial Radiology
[Show abstract][Hide abstract] ABSTRACT: Aim: To compare the qualitative and quantitative information yielded by imaging modalities on the evaluation of the relationship between the maxillary sinus and the apices of posterior teeth. Methods: Three oral radiologists examined 109 panoramic radiographs and cone-beam computed tomography (CBCT) images obtained from a digital archive. A total of 1,875 apices were classified according to their topographic relationship in both imaging modalities. Agreements between the two imaging techniques were examined statistically. The evaluation was repeated in 25% of the sample to statistically evaluate the intraobserver agreement, with a 30-day interval. Results: The values found in the Kappa test for qualitative assessment and the intraclass correlation coefficient (ICC) for quantitative assessment showed nearly perfect and excellent correlation, respectively. Regarding the correlation between the two images, the Kappa test in the quality assessment showed a slight correlation between the palatal roots of the right first molars and second molars. Moreover, the quantitative evaluation by ICC showed poor agreement for the palatal roots of the left first molar and second molar, as well as for the buccomesial of the right second molars and for the buccodistal of the left second molars. Conclusions: There is low correlation between panoramic radiography and CBCT when roots are in contact or above the maxillary sinus floor. A high level of agreement was observed when roots are below the maxillary sinus floor.
Preview · Article · Jun 2015 · Brazilian Journal of Oral Sciences
[Show abstract][Hide abstract] ABSTRACT: This study assessed the effects of high doses of ionizing radiation on eruption rate, odontogenic region morphology, secretory-stage ameloblasts, and enamel organic extracellular matrix (EOECM) of rat maxillary incisors. For the study, 30 male rats were divided into three experimental groups: control (non-irradiated), irradiated by 15 Gy, and irradiated by 25 Gy. Irradiated groups received a single dose of 15 or 25 Gy of X-rays in the head and neck region. The maxillary incisor eruption rate was measured. Sections of 5-µm thickness of the maxillary incisor odontogenic regions were evaluated using bright field light microscopy. Ultrathin sections of secretory ameloblasts and their EOECM were analyzed by transmission electron microscopy (TEM). Irradiated groups showed significantly diminished eruption rate values at the 4th and at the 6th day after irradiation. Reduced optical retardation values were observed in the irradiated groups. The odontogenic region of maxillary incisors from irradiated rats exhibited altered and poorly organized preameloblasts. TEM showed degeneration areas in the secretory-stage EOECM and several autophagosomes in the secretory ameloblasts from irradiated animals. In conclusion, high radiation doses delay eruption and induce disturbances in secretory ameloblasts and EOECM of rat maxillary incisors. These findings may be associated with structural defects of mature enamel.
[Show abstract][Hide abstract] ABSTRACT: Osteoporosis is a degenerative disease that primarily affects postmenopausal women. Based on panoramic radiographs, several assessment methods have been proposed for the diagnosis and evaluation of bone changes and as a predictor of osteoporosis for example the mandibular index.
The purpose of this study is to compare the assessment of mandibular indices on panoramic and cross-sectional images.
Forty-four cone beam computed tomography (CBCT) images from postmenopausal female subjects aged more than 45 years without systemic changes were selected for this study. From those images, cross-sectional and panoramic reconstruction images were assembled into a template for evaluation. The evaluation was conducted by observing the panoramic images and parasagittal sections. The appearance of the inferior cortex of the mandible was classified according to the mandibular index: C1, the endosteal margin of the cortex was even and sharp; C2, the endosteal margin presented semilunar defects or appeared to form endosteal cortical residues; or C3, the cortical layer formed heavy endosteal cortical residues and was clearly porous.
Based on Wilcoxon statistical test (p > 0.01), the data showed no statistically significant difference between the exams.
The mandibular index assigned in tomographic images is comparable to that obtained in panoramic images, indicating a valid use of the index in CBCT images, which can lead to the identification of patients with bone mass loss and a premature referral to further exams and treatment.
No preview · Article · Mar 2014 · Osteoporosis International
[Show abstract][Hide abstract] ABSTRACT: To determine if cone-beam computed tomography (CBCT) enhancement filters influence the diagnosis of longitudinal root fractures.
Forty extracted human posterior teeth were endodontically prepared and fractures with no separation of fragments were made in twenty teeth of this sample. The teeth were placed in a dry mandible and scanned using a Classic i-CAT CBCT device. Evaluations were performed with and without CBCT filters (Sharpen Mild, Sharpen Super Mild, S9, Sharpen, Sharpen 3 x 3, Angio Sharpen Medium 5 x 5, Angio Sharpen High 5 x 5 and Shadow 3 x 3) by three oral radiologists. Inter- and intraobserver agreement was calculated by the kappa test. Accuracy, sensitivity, specificity, and positive and negative predictive values were determined. McNemar test was applied for agreement between all images versus gold standard and original images versus images with filters (p<0.05).
Means of Intraobserver agreement ranged from good to excellent. Angio Sharpen Medium 5 x 5 filter obtained the highest positive predictive value (80%) and specificity (76.5%) value. Angio Sharpen High 5 x 5 filter obtained the highest sensitivity (78.9%) and accuracy (77.5%) value. Negative predictive value was the highest (82.9%) for S9 filter. The McNemar test showed no statistically significant differences between images with and without CBCT filters (p>0.05).
Although no statistical differences was observed in the diagnosis of root fractures when using filters, these filters seem to improve diagnostic capacity for longitudinal root fractures. Further in vitro studies with endodontic treated teeth and research in vivo should be considered.
Full-text · Article · Jan 2014 · Dentomaxillofacial Radiology
[Show abstract][Hide abstract] ABSTRACT: Objective
To assess the image quality of the mandibular third molar region using different milliamperage (mA) settings of cone-beam computed tomography.
Twelve dry mandibles with impacted third molars were scanned with a Kodak 9000 unit (Kodak Dental Systems, Carestream Health, Rochester, NY, USA) using different mA settings (2, 4, 6.3, 8, 10, 12, and 15 mA). Two oral radiologists evaluated the images. They classified the tooth root, periodontal space, lamina dura, trabecular bone, mandibular canal, and overall image quality as excellent, good, poor, or inadequate for diagnosis. Statistical analyses were performed by one-way ANOVA with a post hoc Tukey test to investigate the influence of the mA settings in the image quality of the structures analyzed. The significance level was set at 5 %.
The 15 and 12 mA settings provided the highest mean values for all the evaluated criteria, with significant differences from the values for the other mA settings. The 10, 8, and 6.3 mA settings showed no significant differences in relation to tooth root and periodontal space. For the other evaluated criteria, no significant differences were observed for the 10 and 8 mA settings. The 4 and 2 mA settings gave the lowest mean values.
The best low-dose protocol with good image quality was the 10 mA setting. Lower dose protocols with 8 and 6.3 mA settings can also be used for these purposes, but caution is necessary because of increased image noise.
[Show abstract][Hide abstract] ABSTRACT: Radioprotective agents like selenium are used to reduce the damage caused by radiation in healthy tissues. The aim of this study was to evaluate the effect of sodium selenite on the development of the molars of offspring of rats irradiated during odontogenesis. Twenty pregnant rats were randomly divided into 4 groups: control, irradiated, selenium and selenium/irradiated. The selenium and selenium/irradiated groups received 0.3 mg/kg of sodium selenite at 18 days of pregnancy. The rats of the irradiated and selenium/irradiated groups received a single dose of 4 Gy of X rays on the abdominal region at the 19th day of pregnancy. The offspring was sacrificed at 3 and 4 days after birth for evaluation of the birefringence of the enamel organic matrix, and at 30 days for evaluation of the intercuspal dimensions of the molars. The selenium/irradiated group was similar to the irradiated group with respect to the thickness and irregularity of the enamel organic matrix region in the evaluated birefringence, as the intercuspal dimensions of the molars. In conclusion, sodium selenite had no radioprotective action on the development of the molars of offspring of rats irradiated during odontogenesis and had a toxic effect in the initial time.
Preview · Article · Oct 2013 · Brazilian dental journal
[Show abstract][Hide abstract] ABSTRACT: The objective of this study is to compare the ability of panoramic radiography and cone beam computed tomography (CBCT) in detecting anatomical variations of the mandibular canal and mental foramen.
One hundred twenty-seven preoperative panoramic and CBCT images were evaluated. Two oral and maxillofacial radiologists investigated the presence of bifid mandibular canals and/or additional mental foramina on the right, left, or both sides of the mandible. Intra- and interobserver reliability was determined using Cohen's kappa coefficient. McNemar's test compared the prevalence of mandibular anatomical variations between panoramic radiography and CBCT. The significance level was set at 0.05.
Additional mental foramen and bifid mandibular canal were detected in 1.2 and 7.4 % of the panoramic radiographs and 7.4 and 9.8 % of the CBCT images, respectively. The incidence of anatomical variations on the mandibular canal was not significantly different between both imaging modalities (P > 0.05).
Although CBCT provides better viewing of anatomical structures, including location, shape, and relationship with the surrounding area, panoramic radiography is a conventional imaging modality that can be used in the study of the bifid mandibular canals.
No preview · Article · Aug 2013 · Oral and Maxillofacial Surgery
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to evaluate the radioprotective effect of vitamin E on rat parotid glands by morphometric analysis. Sixty male rats were divided into 5 groups (n=6): control, in which animals received olive oil solution; olive oil/irradiated, in which animals received olive oil and were irradiated with a dose of 15 Gy of gamma radiation; irradiated, in which animals were irradiated with a dose of 15 Gy gamma radiation; vitamin E, which received α-tocopherol acetate solution; vitamin E/irradiated, which received α-tocopherol acetate solution before irradiation with a dose of 15 Gy gamma rays. Half of the animals were euthanized at 8 h, and the remaining at 30 days after irradiation. Both parotid glands were surgically removed and morphometric analysis of acinar cells was performed. Data were subjected to two-way ANOVA and Tukey's test (α=0.05). Morphometric analysis showed a significant reduction in the number of parotid acinar cells at 30 days in olive oil/irradiated and irradiated groups. In groups evaluated over time a significant reduction was shown at 30 days in olive oil/irradiated and irradiated groups, indicating that ionizing radiation caused tissue damage. The vitamin E/irradiated group presented more acinar cells than the irradiated group, but no statistically significant difference was observed (p>0.05). In conclusion, vitamin E seems to have failed as a radioprotective agent on acinar cells in rat parotid glands.
No preview · Article · Jun 2013 · Brazilian dental journal
[Show abstract][Hide abstract] ABSTRACT: The mandibular canine is a robust and long tooth which allows an adequate implantation in the dental arch. It is considered a valuable pillar in many rehabilitating treatments. In order to maintain this important dental element, it is necessary to make a correct diagnosis, for which the knowledge of the different anatomic variations should be kept in mind. The objective of this article is to present a case of a mandibular canine with two roots with their respective root canals. A 21-year-old female patient went to the Radiology Clinic at the Faculty of Odontology of Piracicaba with the indication of a panoramic radiography for preoperative third molars surgery. An unusual root configuration of the mandibular canines was observed. In the cone beam CT, it was observed that the right mandibular canine presented two separate roots, each one with their respective radicular canals. It was concluded that, despite of the low prevalence of anatomical variations, these can occur in the root system of the mandibular canines, as presented in this case report.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to evaluate the validity of the bone density value of potential implant sites in HU obtained by a specific cone-beam computed tomography (CBCT) device. In this study, the HU values obtained using a MSCT scanner were used as the gold standard. Twenty mandibles (40 potential implant sites) were scanned using an MSCT scanner (Somatom Sensation 40) and a CBCT scanner (i-CAT). The MSCT images were evaluated using the Syngo CT Workplace software and the CBCT images, using the XoranCat software. The images were evaluated twice by three oral radiologists, at 60 day intervals. The trabecular bone density of the same area was evaluated on both images. Intraclass coefficients (ICC) were calculated to examine the agreement between the examiners and between the two periods of evaluation. The bone density and area of the ROI were compared by the Student t test and Bland-Altman analysis. ICCs were excellent. The mean HU value obtained using CBCT (418.06) was higher than that obtained using MSCT (313.13), with a statistically significant difference (p < 0.0001). In addition, Bland-Altman analysis showed that the HU measures were not equivalent. In conclusion, the bone density in HU with CBCT images obtained using the device studied proved unreliable, since it was higher than that obtained using MSCT.
Preview · Article · Dec 2012 · Brazilian oral research
[Show abstract][Hide abstract] ABSTRACT: A radiographic interpretation is essential to the diagnosis of invasive cervical resorption (ICR) and the difficulty in distinguishing this lesion from internal root resorption has been highlighted in the literature. This paper reports the use of cone beam computed tomography (CBCT) in the diagnosis of ICR. The cases reports describe how CBCT can be used to make a differential diagnosis and also show that the use of this technology can provide relevant information on the location and nature of root resorption, which conventional radiographs cannot. As a result, the root canal treatment was not initially considered. The patients will be monitored and will undergo a scan after a short period of time to detect any small changes. It was observed that both cases benefited from CBCT in the diagnosis of ICR, because this imaging modality determined the real extent of resorption and possible points of communication with the periodontal space.
Preview · Article · Oct 2012 · Brazilian dental journal
[Show abstract][Hide abstract] ABSTRACT: This study aimed to assess the reliability of multidetector computed tomography (MDCT) in determining the surgical risk of the inferior alveolar neurovascular bundle in extractions of third molars.
The sample comprised thirty-three individuals (63 third molars) who underwent preoperative evaluation by MDCT before extraction of impacted mandibular third molars. MDCT was used to determine the relationship between the roots of the third molars and the mandibular canal, and the course of the mandibular canal. Inferior alveolar nerve (IAN) exposure and the presence of hemorrhage were analyzed after removal of the teeth. IAN neurosensory deficit was recorded after 7 days. Clinical and MDCT findings were compared using Fisher's exact test (P < 0.05).
There was a statistically significant association between IAN exposure and the tomographic relationship between the roots of third molars and the mandibular canal (P = 0.015). Conventionally, all cases of IAN neurosensory deficit and hemorrhage occurred when the roots of the third molar presented in an at-risk relationship with the mandibular canal, however, this association was not statistically significant (P > 0.05). A statistically significant association was found between the lingual course of the mandibular canal and IAN exposure (P = 0.03).
MDCT is an effective tool for determination of the surgical risk to the inferior alveolar neurovascular bundle in extraction of mandibular third molars.
No preview · Article · Mar 2012 · Anatomia Clinica
[Show abstract][Hide abstract] ABSTRACT: Abstract Objective: To test the reproducibility and validity of angular measurements from virtual lateral cephalometric radiography (LCR) reconstructions (full and hemifacial on both sides) derived from cone beam computed tomography (CBCT). Materials and Methods: Fifty-eight CBCT and LCR images were selected. CBCT volume data were imported into Nemotec software, and virtual LCR images and tomographic slices from CBCT images were assessed. Three observers digitized landmarks used for 12 angular measurements in CBCT images from all patients at two different times. The LCR were evaluated by two examiners, and the mean of the measurements was used as the gold standard. Results: The virtual hemifacial LCR of tomographic slices on the right side showed statistically different higher measures. The same modality on both sides showed less absolute differences for most measures except FMIA and interincisal angles. All modalities had excellent reproducibility. Conclusions: The angular measurements made on virtual LCR reconstructions derived from CBCT are reproducible and valid. Some advantage was found over virtual hemifacial LCR on both sides of the image, mainly in its handling facility.
No preview · Article · Feb 2012 · The Angle Orthodontist
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to evaluate the influence of the intergonial distance during the formation of panoramic radiographic images by means of horizontal and vertical measurements.
30 macerated mandibles were categorized into 3 different groups (n = 10) according to their intergonial distances as follows: G1, mean distance 8.2 cm, G2, mean distance 9.0 cm and G3, mean distance 9.6 cm. Three metal spheres 0.198 cm in diameter and placed at an incline using an isosceles triangle were separately placed over the internal and external surfaces of the mandibles before radiographic exposure for the purpose of taking the horizontal and vertical measurements. The occlusal planes of the mandibles were horizontally placed on the chin rest of the panoramic machine Orthopantomograph® OP 100 (Instrumentarium Imaging, Tuusula, Finland) and were then radiographed. In the panoramic radiographs, an expert radiologist measured the distances between the metal spheres in the horizontal and vertical directions using a digital caliper. The data were tabled and statistically analysed by Student's t-test and analysis of variance with Tukey post-test (α = 0.05).
In all three groups magnification of the distances between spheres was observed when compared with the real distance in both horizontal and vertical measurements (p < 0.05). Differences in both horizontal and vertical measurements were observed between the different regions (p < 0.05), however there were no differences between groups in the same region (p > 0.05). Differences between horizontal and vertical measurements were observed in different regions in all evaluated groups (p < 0.05).
The intergonial distance is a factor that had no influence on image formation in the panoramic radiograph.
Full-text · Article · Jan 2012 · Dentomaxillofacial Radiology
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to assess the reliability of four panoramic radiographic findings, both individually and in association, in predicting the absence of corticalization between the mandibular canal and the third molar on cone beam CT (CBCT) images.
The sample consisted of 72 individuals (142 mandibular third molars) who underwent pre-operative radiographic evaluation before extraction of impacted mandibular third molars. On panoramic radiographs, the most common signs of corticalization (darkening of roots, diversion of mandibular canal, narrowing of mandibular canal and interruption of white line) and the presence or absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were evaluated.
Darkening of roots and interruption of white line associated with the absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were statistically significant, both as isolated findings (p = 0.0001 and p = 0.0006, respectively) and in association (p = 0.002). No statistically significant association was observed for the other panoramic radiographic findings, either individually or in association (p > 0.05).
Darkening of roots and interruption of white line observed on panoramic radiographs, both as isolated findings and in association, were effective in determining the risk relationship between the tooth roots and the mandibular canal, requiring three-dimensional evaluation of the case.
Full-text · Article · Jan 2012 · Dentomaxillofacial Radiology