Feasibility of photon-counting computed tomography as a novel imaging modality for challenging endodontic diagnostic tasks

Photon-counting computed tomography (PCCT) is an innovative technological advancement in relation to x-ray detectors which offers ultra-high-resolution images. The current study aimed to evaluate the visualization ability of PCCT compared to cone-beam computed tomographic (CBCT) devices for challenging endodontic diagnostic tasks. A reference image of an anthropomorphic phantom was acquired using an industrial micro-CT device. Thereafter, the phantom was scanned with three imaging devices, which included PCCT scanner (NAEOTOM Alpha) and two CBCT devices (3D Accuitomo 170 and NewTom VGi evo) having standard and high-resolution acquisition protocols. The diagnostic tasks involved visualizing fine endodontic structures (apical delta, narrow canal, and isthmus) and root cracks. Three experienced examiners assessed the images and were blinded to the PCCT and CBCT devices. Each image was rated according to a three-grade scale (appropriate, acceptable, or inappropriate) for the diagnostic tasks. In relation to fine endodontic structures grouped together, PCCT showed similar diagnostic performance compared to the reference image (p > 0.05). As for the CBCT devices, an excellent performance was only observed with the 3D Accuitomo 170 device at a high-resolution acquisition mode (p > 0.05). The visualization of root cracks was also better with 3D Accuitomo 170 compared to other devices (p < 0.05). Overall, PCCT and 3D Accuitomo 170 at a high-resolution setting showed similar performance for visualizing fine endodontic structures. In addition, the high-resolution CBCT protocol was superior for visualizing root cracks compared to both PCCT and other standard- and high-resolution CBCT protocols.

Could the radiographic image quality be affected by the excessive use of the photostimulable phosphor plate?

The study aimed to assess the influence of excessive use of a photostimulable phosphor plate (PSP) on the density, image noise, and contrast of radiographs. For that, radiographs of an acrylic block were acquired with a PSP of the Express intraoral system to assess the density and image noise. Initially, five images were obtained and exported (first group). After 400 exposures to X-rays and scannings of PSP, other five images were obtained and exported (second group). The same procedure was done after 800 (third group), 1200 (fourth group), 1600 (fifth group), and 2000 acquisitions (sixth group), resulting in 30 images to be evaluated. The mean and standard deviation of the gray values were calculated for the images using the ImageJ software. For contrast analysis, radiographs of an aluminum step-wedge were acquired with a new PSP following the same acquisition intervals. The percentage of contrast variation was calculated. Another two unused PSP receptors were employed to evaluate the method's reproducibility. The comparison of the results among the acquisition groups was performed with one-way Analysis of Variance (α=0.05). Intraclass Correlation Coefficient (ICC) assessed the reproducibility of the receptors. Image noise did not differ among the groups (p>0.05). There was a slight increase in density after 400 acquisitions and a slight difference in contrast for all acquisition groups without a pattern of increase or decrease (p<0.05). ICC showed excellent reliability for the methods. Therefore, excessive PSP use slightly affected the radiograph's density and contrast.

Tackling cardiovascular prevention after coronary disease settled: the challenges of guideline implementation

Funding Acknowledgements

Type of funding sources: None.

Purpose

Cardiovascular disease (CVD) as it is known, is a multifactorial disease that needs to be addressed exactly in that way. Knowledge deficit regarding symptoms and unadjusted lifestyles are still the most relevant nursing diagnoses identified as main causes for readmissions in patients with CVD (1). Recent guidelines evidenced that after a CVD event, patients should attend to their lifestyle choices and health behaviors, in order to avoid future events, as this works in a cardioprotective way (2). Having programs structured in a way that makes it possible to involve both population and person-centered strategies all teamed up, could be a way of involving patients in their own care, tackling several recommendations at the same time. Our aim is to describe the implementation of a cardiovascular disease prevention program with a multidisciplinary approach and identify the most prevalent CVD risk factors during the first trimester of its implementation.

Methods

In order to improve patient outcomes post-discharge, the program was outlined as follows: firstly. a Multidisciplinary Appointment was structured, with a Cardiologist and a Nurse, where also family is invited, to assess risk factors, therapeutic adherence and quality of life. According to the patient's needs and preferences they can be assigned to the Cardiac Rehabilitation Lab, to the Education Group Sessions on CVD risk factors where a Nutritionist, Psychiatrist and Physiatrist also participate according to the sessions' topic. For more personalized approach it also comprises: Therapeutic Groups and Mental Health Appointment; Nutrition Appointment; and Nursing Counseling at Outpatient clinics for family and person-centered approach. To assess the program at its third month baseline the focus group method was used for patients and professionals perspectives.

Results

The program was implemented from October to December 2021. During that time 24 patients were admitted. Nursing Counseling was needed for almost all patients for different reasons. Out of those, 50% were assigned to the group sessions, 33.33% were assigned to the Cardiac Rehab, 12.5% were oriented to the Nutrition consults and 20,83% to the Mental Health consults. Even though we offered therapeutic groups as an option for some patients, none of them were willing to go. Regarding the modifiable risk factors, 70% of patients had 3 or more risk factors, showing that we do have a high risk population to tackle. Putting it into perspective, the most prevalent risk factors were dyslipidemia (70.83%), tobacco use (70.83%), obesity (54.17%) and hypertension (50%).

Conclusions

Managing a multidisciplinary program can be demanding, and there were several challenges to this program’s implementation such as: short-staffing, structural issues, covid-19 prevention issues, digital systems, agendas, etc.). But focusing on patients' needs and preferences, helped us to do our utmost to make this program happen.

Digital file format does not influence the radiographic diagnosis of vertical root fracture

OBJECTIVE

To evaluate the influence of the file format of digital periapical radiographs on the diagnosis of vertical root fracture (VRF).

STUDY DESIGN

Periapical radiographic images of 34 single-rooted teeth-19 with VRF, and 15 without VRF were acquired using two digital systems-Digora Toto, and Digora Optime, and exported into four different file formats-TIFF, BMP, PNG, and JPEG, totaling 272 radiographs. The radiographs were assessed by five examiners for the detection of VRF, using a 5-point scale (1-definitely absent; 2-probably absent; 3-uncertain; 4-probably present; 5-definitely present). Diagnostic values of area under the ROC curve, specificity, and sensitivity for the diagnosis of VRF were calculated. The results were compared by two-way Analysis of Variance with post hoc Tukey's test. The intra- and inter-examiner agreements were measured by the Kappa test. The significance level was set at 5% for all analyses.

RESULTS

The values of intra-examiner agreement varied from moderate (0.56) to almost perfect (0.81), while the values of inter-examiner agreement varied from fair (0.29) to moderate (0.60). The image file format did not influence the diagnostic values for VRF for any of the radiographic systems tested (p > 0.05). Digora Toto had significantly greater values of area under the ROC curve than Digora Optime for all file formats (p = 0.001).

CONCLUSION

The image file format of periapical radiographs does not influence the diagnosis of VRF, regardless of the digital radiography system.

Do the location and dimensions of the mental foramen differ among individuals of different facial types and skeletal classes? A CBCT study

STATEMENT OF PROBLEM

Knowledge about the location and dimensions of the mental foramen is important for surgical planning and implant placement in the posterior mandibular region.

PURPOSE

The purpose of this clinical study was to assess the location and dimensions of the mental foramen in individuals of different facial type, skeletal class, and sex by means of cone beam computed tomography (CBCT) images.

MATERIAL AND METHODS

CBCT images of 142 individuals (72 women and 70 men) were classified according to the facial type (dolichocephalic, mesocephalic, or brachycephalic) and skeletal class (I, II, or III). The vertical and horizontal locations of each mental foramen were evaluated on panoramic reconstructions, and the greatest height and width of the mental foramen were determined on multiplanar reconstructions. Also, the distances from the mental foramen to the alveolar crest and to the inferior cortex of the mandible were obtained. The data were compared by using the Kruskal-Wallis test and multiway analysis of variance (α=.05).

RESULTS

The facial type, skeletal class, and sex did not influence the vertical (P=1.00) or the horizontal (P>.15) location of the mental foramen. The most frequent location of the mental foramen was between the first and second premolars and below their apices. The dimensions of the mental foramen were not influenced by the studied factors in men (P>.07); conversely, the mental foramen dimensions were influenced for women (P<.03).

CONCLUSIONS

The most frequent location of the mental foramen was between the first and second premolars and below their apices. An influence of the facial type and skeletal class was observed on the dimensions of the mental foramen in women.

Do the dimensions of the hard palate have a relationship with the volumes of the upper airways and maxillary sinuses? A CBCT study

Background

As the hard palate is a central structure of the skull, and its close relationship with the nasal cavity, oral cavity, and maxillary sinuses, it would be of interest to study if there is a relationship between this bone and other structures of the stomatognathic system. Thus, this study aimed to assess the dimensions of the hard palate and associate them with sex, and skeletal and breathing patterns. Also, to investigate if there is a relationship between these dimensions and the volumes of the upper airways and maxillary sinuses.

Methods

Two hundred and ninety-eight CBCT scans of patients were classified according to sex, and skeletal and breathing patterns. Then, the linear dimensions of width and height of the hard palate at the regions of the first premolars and first molars, and the volumes of the upper airways and maxillary sinuses were measured using the CS 3D Imaging and ITK-SNAP software, respectively. Data were submitted to multi-way analysis of variance and linear regression, with a significance level of 5% (α = 0.05).

Results

Sex and facial type influenced the hard palate dimensions (p < 0.05). Males had greater width and height of the hard palate than females (p < 0.0001). It was observed greater width for brachycephalics at the first premolars region (p = 0.0032), and greater height for dolichocephalics at the first premolars (p = 0.0154) and first molars (p = 0.0038) regions. Skeletal malocclusion and breathing pattern did not influence the measurements of the hard palate (p > 0.05). There was a significant relationship between the width and height of the hard palate at the premolar’s region and the total volume of the upper airways (p = 0.018, and p = 0.038), and between both dimensions of the hard palate at the molar’s region and the total volume of the maxillary sinuses (p < 0.0001).

Conclusions

The hard palate dimensions are influenced by sex and facial type, but not by skeletal malocclusion or breathing pattern. Also, there is an association between these dimensions and the volumes of the upper airways and maxillary sinuses.

Influence of Low-Dose Protocols of CBCT on Dental Implant Planning

PURPOSE

To evaluate the influence of low-dose protocols, with different numbers of basis images, on the precision of linear bone measurements in CBCT images.

MATERIALS AND METHODS

Five polyurethane mandibles, with different levels of bone resorption, were used in this in vitro study. To obtain the reference standard, landmarks were made in the mandibular superior and buccal cortices, and then a digital caliper was used to measure the bone height and thickness at these regions. CBCT images were obtained with the PaX-i3D (Vatech) unit set at 50 kV, 4 mA, 0.2-mm voxel size and 50 × 50-mm field of view. Keeping these parameters fixed, each mandible was scanned twice, with different protocols: Low dose (L) had an acquisition time of 24 seconds and 720 basis images, and ultralow dose (UL) had an acquisition time of 15 seconds and 450 basis images. Then, measurements of bone height and thickness were performed on the images, using the previously determined landmarks as reference. The obtained data were submitted to statistical analysis, with a significance level of .05. Analysis of variance, Student t test, and intraclass correlation coefficient were employed.

RESULTS

Regarding bone height, there were no significant differences between the measurements obtained with the L and UL protocols (P = .8648). Additionally, the L and UL protocols did not differ in relation to the reference standard (P = .8717 and P = .9928, respectively). Likewise, there were no significant differences between the measurements obtained with the L and UL protocols (P = .7969) for bone thickness, nor between these protocols and the gold standard (P = .7455).

CONCLUSION

Considering the great demand for precise measurements in implantology, protocols of low-dose radiation can be used without compromising clinical planning.

Influence of skeletal class and facial type on nose dimensions in a Brazilian subpopulation: a CBCT study

Evaluating factors that may influence the nose dimensions and, therefore, contribute to the singularity of a person, is important for obtaining a precise facial reconstruction (FR) in forensic anthropology. Thus, the aim in this study was to evaluate the influence of sex, skeletal class, and facial type on nose dimensions of Brazilian individuals using cone-beam computed tomography (CBCT) scans. CBCT images of 54 males and 67 females were classified according to skeletal class (class I, II, or III) and facial type (brachycephalic, dolichocephalic and mesocephalic). Linear and angular measurements of the nose were performed using the CS 3D Imaging software. The measurements obtained for males and females were compared by one-way ANOVA. Two-way ANOVA was used to compare the measurements in the different skeletal classes and facial types. Significance level was set at 5%. All linear measurements were greater in males (p < 0.05); the angular measurements, however, did not differ between sexes (p > 0.05). Linear and angular measurements of class III males were significantly different from the other classes; the same was observed for the angular measurements in females (p < 0.05). Regarding facial types, some linear measurements were significantly greater in dolichocephalics males (p < 0.05). For females, there was no influence of facial type (p > 0.05), except for the nasal convexity angle. Nose dimensions differed in specific points among different skeletal classes and facial types, and there was sexual dimorphism in all linear nose dimensions. This information may be applicable for nose reconstructions, allowing more reliable FR.

Volumetric evaluation of temporomandibular joints in patients with a chewing-side preference: a CBCT study

This study evaluated the influence of chewing-side preference on the volume of the mandibular condyle and coronoid process and the dynamic parameters of the temporomandibular joint (TMJ). Cone beam computed tomographic scans of both TMJs of 90 individuals with a chewing-side preference were obtained while the patients were in the closed-mouth and maximum mouth-opening positions (test power ≥ 0.80). The preferred chewing side was identified with a chewing gum test as well as by patient self-reports of preferred side and hemispheric dominance (ie, dominant side of the body). Two trained examiners assessed the volume of the mandibular condyle and coronoid process and the dynamic parameters of the TMJs on both sides. The volumes of the mandibular condyle on the 2 sides were compared using a paired t test (α = 0.05). McNemar and Bowker tests of symmetry (α = 0.05) were used for concordance analyses of the dynamic parameters of the TMJ on the chewing and nonchewing sides. No statistically significant difference was observed in the volume of the mandibular condyle (chewing gum test, P = 0.4548; interview, P = 0.7191; hemispheric dominance, P = 0.3471) or coronoid process (chewing gum test, P = 0.7718; interview, P = 0.8072; hemispheric dominance, P = 0.8301) on the chewing and nonchewing sides, regardless of the method used to identify chewing preference. The preferred chewing side also did not significantly affect the dynamic parameters of the mandibular condyle (P = 0.5538). Chewing-side preference does not influence the volume of the mandibular condyle or coronoid process or the dynamic parameters of the TMJ.

Classification and Morphological Analysis of the Hard Palate in Cone-Beam Computed Tomography Scans: A Retrospective Study

PURPOSE

As the hard palate is a central structure of the skull and is involved in orthodontic and surgical procedures, it would be of interest to study the morphological aspects of this bone and its possible variations as per different patterns of skeletal development. Thus, this study aimed to develop a classification for the different morphological characteristics of the hard palate and to evaluate the relationship between these characteristics and the different skeletal patterns, using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

This retrospective and cross-sectional study used CBCT scans of patients seen from January 2014 to December 2016. Carestream Dental 3D Imaging software was applied to classify each patient according to vertical and sagittal skeletal patterns, and to evaluate the 3 morphological characteristics of the hard palate: depth (flat, regular, or deep), inclination (superior, parallel, or inferior), and presence of a bony projection (S-shaped). χ² and Fisher's exact tests evaluated the relationship between the hard palate characteristics and the different skeletal patterns.

RESULTS

A total of 298 CBCT scans (144 males and 154 females) were evaluated. The depth of the hard palate was significantly related to both skeletal patterns in males (P < .05), with Class II and dolichocephalics presenting a greater amount of deep palates, while classes I and III and brachycephalics had a greater amount of regular palates. The inclination of the hard palate was significantly associated with the facial type in females (P < .05), with brachycephalics and mesocephalics presenting a greater amount of parallel palates, whereas dolichocephalics had a greater number of inferiorly inclined palates. Regarding the presence of the S-shape in the hard palate, there was a greater number of this projection in Class II males and brachycephalic females.

CONCLUSIONS

A morphological classification for the hard palate was developed. The morphology of the hard palate varied among the different skeletal patterns.

Assessment of Ramifications in the Apical Region of Root Canals: A Micro-CT Study in a Brazilian Population

The present study used microcomputed tomography (micro-CT) images to assess the prevalence, number, and location of apical ramifications (ARs) in the root canals of different dental groups in a Brazilian population. Three hundred and sixty-seven extracted human teeth, totaling 475 roots, were scanned by micro-CT at 19.6 µm spatial resolution. The obtained images were evaluated by two observers in consensus, and a descriptive analysis was performed to verify the prevalence, number, and location of ARs in each dental group. Chi-square test was used to compare the prevalence of ARs in different types of roots, and one-way analysis of variance compared the number of ARs in the apical 1 mm, 2 mm, and 3 mm of the root. Significance level was established at 5% (α=0.05). ARs were present in 253 (53.3%) of the 475 roots evaluated. A total of 607 ARs were detected, with the vast majority (530) located at one and two millimeters from the main foramen. The highest prevalence of ARs was observed in maxillary canines (65%); maxillary premolars - single-rooted (83.3%), buccal root (80%), and palatine root (73.3%); mandibular premolars (64.2%); mesiobuccal root of maxillary molars (76.6%); and mesial root of mandibular molars (66.6%). For the Brazilian population, most of the ARs are located in the apical 1 and 2 mm of the root, with greater prevalence in the posterior teeth and maxillary canines. These findings suggest the need for additional attention while planning endodontic treatments, including strategies to effectively clean and fill the apical region.

Do the tube current and metal artifact reduction influence the diagnosis of vertical root fracture in a tooth positioned in the vicinity of a zirconium implant? A CBCT study

AIM

To evaluate the influence of the tube current and metal artifact reduction (MAR) tool on the diagnosis of vertical root fractures (VRF) in a tooth adjacent to a zirconium implant, in cone-beam computed tomography (CBCT) images.

METHODOLOGY

Thirty single-rooted teeth (15 with VRF and 15 control group) were individually positioned in a mandible, and scanned with the OP300 CBCT unit. Images were acquired using a standardized protocol: 5 × 5 cm field of view, 0.08-mm voxel size, and 90 kVp. Each tooth was scanned with and without a zirconium implant in its vicinity, using different tube currents (4 mA, 8 mA, and 10 mA) and conditions of MAR (enabled × disabled). Diagnostic values were calculated for each protocol, and compared by multi-way analysis of variance.

RESULTS

The ROC curve and sensitivity values did not differ significantly among the tube currents, regardless of the presence of the implant and MAR condition (p > 0.05). There were also no significant differences among the tube currents for the specificity values (p > 0.05); however, the specificity differed significantly between the "with implant" and "without implant" conditions, within the same MAR condition and tube current (p < 0.05). Specificity was significantly lower when the implant was present (p < 0.05).

CONCLUSION

The presence of a zirconium implant impairs the diagnosis of VRF in teeth adjacent to the artifact-generator material. Neither the tube current nor the MAR tool is effective in improving this diagnostic task. Therefore, in this clinical scenario, the use of the lowest tube current (4 mA), without MAR activation, is recommended.

CLINICAL RELEVANCE

Considering that the tube current is one of the main factors that influence the radiation dose and image quality in CBCT, and that metal artifacts negatively influence the diagnosis of VRF in areas adjacent to the artifact-generator material, it is important to evaluate the effect of this energetic parameter in the diagnosis of VRF in teeth adjacent to zirconium implants.

Mapping the expression of beam hardening artefacts produced by metal posts positioned in different regions of the dental arch

OBJECTIVES

To objectively assess the expression and direction of artefacts in the vicinity of metal posts positioned in different mandibular regions.

MATERIALS AND METHODS

A human mandible had two sockets prepared-anterior and posterior regions-to accommodate a single-rooted tooth. Two CBCT units, Picasso Trio and OP300, were used. CBCT images of the tooth without metal post, and with silver-palladium, nickel-chromium, or cobalt-chromium posts (experimental groups) were individually acquired. Then, 8 lines of interest (LOIs) were determined around the root canal, in an axial reconstruction: 4 in orthogonal (buccal, lingual, mesial, and distal) directions, and 4 in oblique (mesiobuccal, distobuccal, mesiolingual, and distolingual) directions. The mean of gray values was measured for each LOI.

RESULTS

For the OP300, in general, all experimental groups showed greater expression of hyperdense streaks in orthogonal LOIs and greater expression of hypodense streaks in oblique LOIs. For the Picasso Trio, for both mandibular regions, the buccal LOI showed greater expression of hypodense streaks; conversely, greater expression of hyperdense streaks was observed in the distal and distobuccal LOIs in the anterior region and in the mesiolingual LOI in the posterior region. The silver-palladium group showed significantly greater expression of beam hardening artefacts in the posterior region of the mandible, regardless of the CBCT unit (p < 0.05). The mandibular posterior region showed significantly lower gray values than the anterior region (p < 0.05).

CONCLUSION

The expression and direction of artefacts produced in the vicinity of metal posts vary according to the mandibular region, composition of the post, and CBCT unit.

CLINICAL RELEVANCE

The mapping of artefacts produced by metal posts reveals the root regions with greater expression of hypodense and hyperdense artefacts, which may contribute to recognizing regions more likely to mimic or hide root fracture lines.

Soft tissue thickness in Brazilian adults of different skeletal classes and facial types: A cone beam CT - Study

The aim in this study was to evaluate the influence of skeletal class, facial type, and sex on soft tissue thickness (STT) of the craniofacial midline in a Brazilian subpopulation. Thus, 121 cone beam computed tomography (CBCT) scans (54 males and 67 females, age 21 to 40 yrs) composed the study sample. Patients were classified according to skeletal class (class I, II, and III) and facial type (brachycephalic, mesocephalic, and dolichocephalic), and STT was measured (mm) in 10 landmarks in the craniofacial midline for each CBCT scan. Multivariate analysis of covariance evaluated facial STT with regard to multiple independent variables (sex, age - covariate, facial type, and skeletal class). TEM and rTEM assessed the intra-examiner agreement. STT was significantly greater in males than in females for all regions measured (p < 0.05), except for the pogonion-pogonion' landmark (p>0.05). In general, class III individuals had significantly thicker soft tissue in the maxilla - subspinale-subnasale', prosthion-labrale superius', and incision-stomion' regions, while class II subjects had thicker soft tissue in the infradentale-labrale inferius' mandibular landmark (p < 0.05). Regarding facial type, dolichocephalic individuals showed significantly thicker soft tissue in the supramentale-supramentale' mandibular landmark, whereas brachycephalic subjects had thicker soft tissue in maxillary regions - prosthion-labrale superius' and incision-stomion' (p < 0.05). rTEM values were below 5% for most landmarks, and all TEM values were below 1 mm. Skeletal class and facial type influence STT, showing a soft tissue compensation, with deeper soft tissue in areas with lower skeletal development, and/or where bone is positioned more posteriorly.

Efficacy and Safety of Botulinum Toxin Type A on Persistent Myofascial Pain: A Randomized Clinical Trial

This study assessed the safety and efficacy of three different doses of BoNT-A for persistent myofascial pain (MFP). One hundred female subjects were randomly assigned into five groups (n = 20): oral appliance (OA), saline solution (SS) and three BoNT-A groups with different doses. Pain intensity and pressure pain threshold were evaluated up to 24 weeks after treatment. Adverse effects related to muscle contraction, masticatory performance, muscle thickness and mandibular bone volume were also assessed. Changes over time were compared within and between groups. The “nparLD” package and Wilcoxon signed-rank test were used to analyze the data. BoNT-A reduced pain intensity (p < 0.0001) and increased pressure pain threshold (p < 0.0001) for up to 24 weeks compared to the placebo. No differences were found between BoNT-A and OA at the last follow-up. A transient decline in masticatory performance (p < 0.05) and muscle contraction (p < 0.0001), and a decrease in muscle thickness (p < 0.05) and coronoid and condylar process bone volume (p < 0.05) were found as dose-related adverse effects of BoNT-A. Regardless of the dose, BoNT-A was as effective as OA on MFP. Notwithstanding, due to BoNT-A dose-related adverse effects, we suggest the use of low doses of BoNT-A in MFP patients that do not benefit from conservative treatments.

Does the addition of a lead foil to digital radiographic receptors influence image contrast and approximal caries lesions diagnosis?

Objectives:

To access the influence of the addition of a lead foil to intraoral digital radiographic receptors on image contrast and approximal caries lesions diagnosis.

Methods:

40 posterior teeth were distributed in silicone phantoms composed of two premolars, two molars and a non-test canine. Radiographic images of the phantoms were obtained with and without the incorporation of a lead foil, using the Digora Optime and Digora Toto systems. Four observers scored the images for the presence of caries lesions, using a 5-point scale. Images of an aluminum step wedge were acquired with and without the incorporation of a lead foil. Gray values and standard deviation of gray values were calculated in different thickness of the step wedge and, then, contrast variation was calculated.

Results:

Presence of a lead foil did not influence caries lesions diagnostic values, regardless of the type of digital system (p > 0.05). In general, the objective analysis was not influenced by the presence of a lead foil in any of the tested systems (p > 0.05). However, Digora Toto images showed greater gray values, lower standard deviation of gray values and lower contrast variation, regardless of the presence of the lead foil (p < 0.05).

Conclusions:

The addition of a lead foil to intraoral digital receptors did not influence image contrast nor caries lesions diagnosis.

Variations in pulp volume between normotensive and hypertensive individuals on CBCT imaging

OBJECTIVES

To compare the pulp volume of individuals with altered and normal systemic blood pressure (BP) in order to verify if high BP promotes dimensional modifications in the pulp space.

MATERIALS AND METHODS

Cone beam computed tomography scans of 91 patients (49 females and 42 males, mean age 31.7 ± 6.38 years) who had a healthy maxillary canine were selected. Values of arterial BP measured at two dental visits were used to classify the sample as normal BP (< 130 × 80 mmHg) and altered BP (≥ 130 × 80 mmHg); 49 patients had normal BP and 42 had altered BP. One oral radiologist evaluated each patient's pulp and tooth volumes, using semi-automatic segmentation, and the tooth length. Data were submitted to Student's t test and logistic regression, with a significance level of 5% (p < 0.05).

RESULTS

Pulp volume (p = 0.0027), pulp volume/tooth volume (p = 0.0013), and pulp volume/tooth length (p = 0.0007) ratios were greater in the altered BP group. Conversely, there was no difference in tooth volume between the groups (p = 0.0697). A logistic regression model (p = 0.0002) using pulp volume and age enabled the development of a formula for predicting altered BP, with 68% accuracy.

CONCLUSIONS

Individuals with altered systemic BP have greater pulp volumes than those with normal BP. The formula developed in this study may indicate the presence of altered BP.

CLINICAL RELEVANCE

As arterial hypertension is a silent disease that produces no warning signs or symptoms, identification of modifications in the pulp volume in cone beam computed tomography scans may be an adjuvant sign of the diagnosis of this disease.

Bone changes in the temporomandibular joints of older adults: A cone-beam computed tomography study

AIMS

To assess the prevalence of degenerative bone changes in the temporomandibular joint (TMJ) of older adults using cone-beam computed tomography (CBCT), and to verify possible associations between these findings and patient health history.

METHODS

CBCT scans comprising both TMJs were acquired for 137 patients aged 65+, regardless of TMD status. Images were assessed by two oral radiologists and evaluated for the presence of flattening, erosion, sclerosis, subchondral cysts, and osteophytes in the TMJ bony components, and self-reported patient systemic health histories were retrieved from records.

RESULTS

There were 59 males, and the mean age was 73.35 ± 6.28. A total of 31.4% had bone changes in both TMJs, and 65.7% had bone changes in at least one side. Bone changes were more prevalent in females, with subchondral cysts (63.3%) and osteophytes (60%) the most common findings. There was a higher prevalence of osteoporosis/osteopenia (38.5%) and connective tissue disorders (39.8%) in patients with TMJ bone changes than in those with normal TMJs.

CONCLUSION

Degenerative bone changes of TMJ were prevalent among older adults, and females were more affected. There was a greater prevalence of osteoporosis/osteopenia and connective tissue disorders in patients with TMJ bone changes than in subjects with normal TMJs.

Artifact expression of polylactic acid/hydroxyapatite/graphene oxide nanocomposite in CBCT: a promising dental material

OBJECTIVE

To evaluate the artifact expression of a new material-polylactic acid (PLA)/hydroxyapatite (HA)/graphene oxide (GO) nanocomposite-and compare it with that of commonly used dental materials, using cone-beam computed tomography.

MATERIALS AND METHODS

Cylinders of amalgam alloy, metal alloy, titanium, gutta-percha, and PLA/HA/GO were individually placed in the center of an acrylic phantom. Three images of each phantom + cylinder set were acquired using a Picasso Trio unit (Vatech, Hwaseong, South Korea) set at 90 kVp, 3.7 mA, 0.2 mm³ voxel size, and 12 × 8.5 cm FOV. Three images of a control group (sound phantom) were also obtained. Eight ROIs were established in each image to evaluate the standard deviation (S.D.) of gray values in the ImageJ Software. The Kruskal-Wallis test with the Student-Newman-Keuls post hoc was employed, considering a significance level of 5%.

RESULTS

There were no significant differences in S.D. between the control and PLA/HA/GO images (p = 0.712). Both control and PLA/HA/GO showed fewer image artifacts than the other materials (p < 0.05). The images of the amalgam alloy did not differ from the metal alloy images (p = 0.691), showing more artifacts than the gutta-percha (p = 0.028) and titanium (p = 0.051).

CONCLUSIONS

The PLA/HA/GO produced fewer artifacts and a better-quality image than the other tested materials.

CLINICAL RELEVANCE

The PLA/HA/GO has physical and biological properties similar to those of dental materials. Since it has produced fewer image artifacts, this new nanocomposite may be employed in the near future, enhancing the diagnosis in CBCT.

Accuracy of ITK-SNAP software for 3D analysis of a non-regular topography structure

OBJECTIVES

To evaluate the accuracy of ITK-SNAP software for measuring volumes of a non-regular shape structure, using cone beam computed tomography (CBCT) scans, besides for developing a mathematical model to correct the software measurement error in case it existed.

METHODS

A phantom made by moulding a rubber duck's head was filled with total (38,000 mm³) and partial volumes of water (7000 mm³, 14,000 mm³, 21,000 mm³, 28,000 mm³ and 35,000 mm³), which constituted the gold standards. The sound phantom and the phantom filled with different volumes of water were scanned in a Picasso Trio CBCT unit set at 80 kVp, 3.7 mA, 0.2 mm³ voxel and 12 × 8.5 cm field of view. Semi-automatic segmentation was performed with ITK-SNAP 3.0 software by two trained oral radiologists. Linear regression analyzed the relation between ITK-SNAP calculated volumes and the gold standard. Intraclass correlation coefficient was applied to analyze the reproducibility of the method. Significance level was set at 5%.

RESULTS

Linear regression analysis showed a significant relationship between ITK-SNAP volumes and the gold standard (F = 22,537.3, p < 0.0001), with an R² of 0.9993. The average error found was 4.7 (± 4.3) %. To minimize this error, a mathematical model was developed and provided a reduction of it. ICC revealed excellent intra-examiner agreements for both examiners 1 (ICC = 0.9991, p < 0.0001) and 2 (ICC = 0.9989, p < 0.0001). Likewise, inter-examiner agreement was excellent (ICC = 0.9991, p < 0.0001).

CONCLUSION

The software showed to be accurate for evaluating non-regular shape structures. The mathematical model developed reduced an already small error on the software's measurements.

Influence of the incorporation of a lead foil to intraoral digital receptors on the image quality and root fracture diagnosis

OBJECTIVE

To evaluate the quality of images obtained with the addition of a lead foil to intraoral digital receptors.

METHODS

Radiographic images of 34 single-rooted human teeth - 19 with vertical root fracture (VRF) and 15 of the control group - were obtained with and without the addition of a lead foil, using the VistaScan, Express, Digora Optime and Digora Toto systems. Images were evaluated by five observers regarding the diagnosis of VRF, using a 5-point scale. In a second moment, an observer preference analysis related to the presence of the lead foil was performed. Images of an acrylic phantom were also obtained with and without the addition of a lead foil, and the quantities of uniformity, grey value and standard deviation of grey values were obtained.

RESULTS

There were no significant differences in the VRF diagnostic values, considering the presence of the lead foil. Regarding the image quality preference, the observers preferred images acquired with the lead foil for all systems tested, but with greater values for Digora Optime (61.33%) and Express (61.33%). The presence of the lead foil did influence the image uniformity in all systems tested ( p < 0.05). Moreover, the lead foil increased the mean of grey values for Digora Optime and Express images ( p < 0.05), however it did not influence the SD in any of the digital systems ( p > 0.05).

CONCLUSION

The addition of a lead foil to intraoral digital receptors produces a positive effect in the image quality objectively detected by means of uniformity and subjective visual preference.

Esthetic perception of asymmetric canines treated with space closure in maxillary lateral incisor agenesis

OBJECTIVE

This article assesses the esthetic opinion of the experts involved in dental restoration (general dentists, orthodontists, prosthodontists) and laypeople. Differences in esthetic opinion among the studied groups are assessed.

MATERIAL AND METHODS

A questionnaire was constructed based on four photographs. A quantitative esthetic appreciation using a numerical scale was requested from four groups of observers. The final sample consisted of 434 participants: 142 laypeople, 141 general dentists, 100 orthodontists, and 51 prosthodontists. The photographs presented were based on the same lips and modified from the same intraoral photograph with asymmetric canines: the right canine was smaller than the left canine and had a lower gingival margin. A mirror image of the right canine was digitally made to create symmetry.

RESULTS

There were statistically significant differences (P < 0.05) in the assessments made across the different groups of observers. For all questions, the laypeople assigned significantly higher scores (P < 0.05) than the orthodontists and prosthodontists. However, there was no significant difference between groups, and all the groups considered the photograph with the larger canines to be more esthetic. The dental professionals and the laypeople disagreed the most regarding their assessment of the least esthetic image.

CONCLUSION

There were differences between the four observer groups in their scoring of the photographs from 0 to 10 relative to the more pleasing esthetics of closure of space with asymmetric canines. However, there were no differences in the results when evaluating each type of canine relative to the form. The canine with the most prominent shape was considered to be more esthetic by all the groups.

Development and validation of a formula based on maxillary sinus measurements as a tool for sex estimation: a cone beam computed tomography study

BACKGROUND

As sex estimation is an important step to delineate the biological profile, the development of tools employing anatomical structures which may maintain their integrity even after extreme events, such as the maxillary sinus, become useful for forensic identification. Thus, the aim in the present study was to develop and validate a formula for sex estimation through measurements in the maxillary sinuses in a Brazilian population, using cone beam computed tomography (CBCT) scans.

MATERIAL AND METHODS

Linear and volumetric measurements in the maxillary sinus were performed bilaterally in 94 CBCT scans from 45 males (mean age 25.2 ± 0.79) and 49 females (mean age 23.7 ± 0.50). The OnDemand 3D software was employed for linear measurements (height, length and width of, and the largest distance between the right and left maxillary sinuses), while the ITK-SNAP 3.0 segmentation software was used to acquire the volume. The data obtained was applied to a mathematical model for sex estimation. To validate the developed formula, another sample composed of 60 CBCT images of Brazilian individuals was tested.

RESULTS

Overall, maxillary sinuses' measurements were significantly higher in males, without statistically significant differences between the right and left sides within each group. The most dimorphic measurement was the height, with an accuracy of 77.7% regarding sex estimation. The formula created lead to a sex estimation of 87.8% for females and 80% for males, with an overall accuracy of 84%. When the formula validity was tested in another sample, it showed an accuracy of 82.4%.

CONCLUSION

The formula developed through measurements in the maxillary sinus using CBCT scans showed an accuracy of 84% for sex estimation and can be applied as a complementary method for human identification in the Brazilian population.

The influence of number of line pairs in digital intra-oral radiography on the detection accuracy of horizontal root fractures

AIM

Line pairs are the unit for measurement of resolution and are related to the spatial quality of the system. Thus, the objective of this study was to evaluate the influence of number of line pairs in digital intra-oral radiography on the detection accuracy of horizontal root fractures.

MATERIALS AND METHODS

Sixty-four extracted single-root human teeth were used. Thirty-two had horizontal root fractures created and were mounted in dry human mandibles. The teeth were radiographed with two digital receptors: the Digora Optime (14.3 lp mm-1) and the Digora Toto (26.3 lp mm-1). Images were viewed under standardized conditions by 3 calibrated examiners using the respective dedicated software (Digora for Windows 2.6(®) and Scanora(®) ). Digora Toto(®) images were also evaluated through the Digora for Windows 2.6(®) software. The results were statistically analyzed based on the area under the ROC curve for each examiner.

RESULTS

Pairing Digora Toto(®) with Scanora(®) allowed for greater accuracy in horizontal root fractures diagnosis, while images acquired with that same system seem to lose accuracy when visualized with Digora for Windows 2.6(®) . Pairing Digora Optime(®) with Digora for Windows 2.6(®) resulted in the lowest accuracy for horizontal root fractures diagnosis.

CONCLUSIONS

The higher number of line pairs and the consequent higher image resolution provided by the Digora Toto(®) system and its dedicated software seem to enhance the accuracy of horizontal root fractures diagnostic imaging.

Assessment of Volume and Height of the Coronoid Process in Patients With Different Facial Types and Skeletal Classes: A Cone-Beam Computed Tomography Study

PURPOSE

To determine the height and volume of the mandibular coronoid process (CP) by cone-beam computed tomography (CBCT) and to identify the presence of any correlations of these measurements with age, gender, facial type, and skeletal class.

MATERIALS AND METHODS

The sample consisted of 132 patients from a departmental routine patient base. After CBCT, CP height was determined using OnDemand 3D software (CyberMed, Seoul, Republic of Korea), and CP volume was obtained using ITK-SNAP 3.0 software (Cognitica, Philadelphia, PA). Measurements were subjected to analysis of covariance against facial type, skeletal class, gender, and age, with a significance level of 5%.

RESULTS

CP height and volume were similar regardless of age, facial type, and skeletal class. However, the 2 measurements were statistically different regarding gender, with larger values for men than for women.

CONCLUSIONS

These observations suggest that gender is the only factor influencing the height and volume of the CP.

Western blot seroindeterminate individuals for human T-lymphotropic virus I/II (HTLV-I/II) in Fortaleza (Brazil): a serological and molecular diagnostic and epidemiological approach

How to handle Western blot (WB) seroindeterminate individuals for Human T-lymphotropic Virus 1/2 (HTLV-1/2) constitutes a challenge for blood banks and families. We made a cross-sectional study of 191 enzyme linked immunoassay (EIA) reactive individuals from the hematological center (HEMOCE) of Fortaleza (Brazil), examining their serological (WB) and molecular (PCR) diagnosis, and demographic profiles, as well as a possible association of their condition with other infectious pathologies and risk factors. Ethical institutional approval and personal consent were obtained. Out of 191 EIA reactive individuals, 118 were WB seroindeterminate and 73 were seropositive for HTLV-1/2. In the PCR analysis of 41 WB seroindeterminate individuals, 9 (22%) were positive and 32 (78%) were negative for HTLV-1/2. The demographic analysis indicated a trend towards a predominance of males among the seroindeterminate individuals and females in the seropositive ones. The seroindeterminate individuals were younger than the seropositive ones. We did not find any association of these conditions with syphilis, Chagas disease or HIV or hepatitis, and with risk factors such as breast-feeding, blood transfusion, STD (syphilis) and IDU.

[Cerebral arterial aneurysm in a child with acquired immunodeficiency syndrome: case report]

Cerebral aneurysmal arteriopathy of the circle of Willis is an uncommon manifestation of acquired human immunodeficiency virus (HIV) infection and up to now only 15 cases have been published in the literature. For this reason we add our experience of this rare case, and review the most important aspects related to this entity. The patient is a 6 year old male with perinatal transmitted AIDS, tetraparethic, developed symptoms characterized by episodes of dystonic postures. The computed tomography of the brain showed aneurismal arteriopathy of the circle of Willis. He had a previous normal examination. The review of the literature shows the pathological abnormalities of the affected vessels are mainly medial fibrosis, with destruction of the internal elastic lamina and intimal hyperplasia. The etiology for the vasculitis is unknown. Varicela zoster virus, as well as HIV by itself, can be related to the physiopathology of the vasculitis. On conclusion, it can be said that although uncommon, such complications are of great importance by the fact that the patients with vascular aneurismal arteriopathy are in high risk for vascular accidents, and once a diagnosis was made, death occurs in less than 6 months, according to the literature.

Activities in other European countries

This paper comprises a compilation of five papers, originating from Austria, Belgium, Denmark, Portugal and the United Kingdom. It describes the actions and measures taken for the transposition of the medical devices directives as well as the implementation of a vigilance system. It also includes aspects of the implementation of a trans-European system for data exchange in the field of medical device vigilance system.

Some ectoparasites of commensal rodents from Huambo, Angola

Eight species of ectoparasites were collected from 166 commensal rodents, including Rattus rattus (L.), Rattus norvegicus (Berkenhout), and Mus musculus (L.), from January to December 1986, in Huambo, Angola. The oriental rat flea, Xenopsylla cheopis (Rothschild), was the predominant species with respect to mean intensity and prevalence. Other fleas collected were Ctenophthalmus (Ethioctenophthalmus) machadoi Ribeiro, Dinopsyllus (Dinopsyllus) smiti Ribeiro, and Echidnophaga gallinacea (Westwood). The mite Laelaps (Echinolaelaps) muricola Trägärdh, the louse Polyplax spinulosa (Burmeister), one species of Ixodes Latreille, and one species of Ornithonyssus Sambon were also recorded. The following represent new host records: C. machadoi from R. rattus and R. norvegicus, D. smiti from M. musculus, and L. muricola from R. rattus and M. musculus. For the first time, the monthly flea indices throughout the year are presented for Angola.

Observations on cattle ticks in Huila Province (Angola)

In Huila Province of Angola, 3864 ticks were collected during a parasitological survey carried out in the rainy season from October 1990 to April 1991. The samples were collected from cattle gathered for the annual vaccination campaign against contagious bovine pleuropneumonia, anthrax and blackleg in 18 veterinary stations of six municipalities. After tick classification, the following proportions of ticks were obtained: Rhipicephalus evertsi mimeticus (27.1%), Amblyomma pomposum (26.4%), Boophilus decoloratus (19.0%), Rhipicephalus zambesiensis (9.4%), Rhipicephalus duttoni (8.3%), Hyalomma marginatum rufipes (3.8%), Hyalomma truncatum (3.0%), Rhipicephalus punctatus (2.5%) and Ixodes cavipalpus, Rhipicephalus lunulatus, Rhipicephalus turanicus, Rhipicephalus evertsi evertsi, Rhipicephalus simus, each less than 1%. These ticks are well known in southern Africa as vectors of diseases caused by protozoa and rickettsiae (babesiosis, theileriosis, anaplasmosis and cowdriosis). Control programmes against ticks and tick-borne diseases should be based on critical studies regarding costs/risks/benefits in relation to socio-economic and ecological frameworks.