Radiofrequency-Induced Heating of Amalgam Restorations and Dental Implants during 1.5T Magnetic Resonance Imaging.

Objectives: This study aimed to evaluate radiofrequency-induced heating of different amalgam restorations and dental implants during 1.5T magnetic resonance imaging (MRI). Materials and Methods: Standardized class I cavities (5 mm long, 3 mm wide, and 3 mm deep) were prepared on the occlusal surface of 45 extracted human third molars. The samples were restored by three different types of amalgam including Cinalux amalgam (non-gamma-2, spherical), GS-80 (non-gamma-2, admix), and GK-110 amalgam (non-gamma-2, admix in silver). As a separate intervention group (G4), five titanium mini drive-lock implants with 2mm diameter and 10mm length were also selected and mounted to the base of the Eppendorf tube with 3mm of the implants extending above the mounting putty. The box containing the specimens was placed parallel to the long axis of the standard head and neck coil of the MRI device (64MHz radio-frequency energy with 25kW amplifier, 1.5T). Temperature fluctuations of the metallic materials in each group were monitored during MRI scans using a calibrated thermometer. One-way ANOVA was used to compare temperature changes among the amalgam groups (P<0.05). Results: Temperature elevations ranged from 0.21°C to 0.70°C in amalgam restorations and from 0.35 to 0.47°C in dental implants. The temperature changes among the three amalgam agents were not statistically significant. Conclusion: According to our findings, the radiofrequency-induced heating of amalgam restorations and dental implants during MRI examination can be considered within acceptable ranges. Therefore, amalgam restorations and dental implants can be categorized as "MR safe" in terms of radiofrequency-induced heating during 1.5 T MRI.

Comparison of temporomandibular joint osseous components in unilateral and bilateral cleft lip and palate patients and normal controls: A CBCT study.

OBJECTIVE: The objective of this study was to conduct a comparative analysis of the components of the temporomandibular joint in individuals with unilateral, bilateral cleft lip and palate (CLP), and in healthy individuals, utilizing cone beam computed tomography (CBCT) images. METHOD AND MATERIAL: The present study employed a cross-sectional design and recruited participants aged 18 to 30 years. The participants were categorized into three groups: a control group consisting of 36 individuals without any cleft, a group of 35 patients with unilateral cleft lip and palate (UCLP), and a group of 15 patients with bilateral cleft lip and palate (BCLP). The analysis of CBCT images encompassed the examination of condylar height and angulation, glenoid fossa height and width, articular eminence inclination, as well as joint spaces across all three groups. The Kruskal-Wallis and Mann-Whitney tests were employed to ascertain the significant differences among the three groups. RESULTS: The UCLP and BCLP groups demonstrated a statistically significant reduction in condylar height and articular eminence inclination in comparison to the control group. Furthermore, a significant difference in the width of the glenoid fossa was seen between the group with clefts and the control group. CONCLUSION: The CBCT images showed significant differences in several aspects of the temporomandibular joint, including condylar height, articular eminence inclination, and glenoid fossa width, in individuals with cleft palate. These abnormalities can contribute to the development of temporomandibular joint diseases. Therefore, recognizing these distinctions can help prevent further deterioration and progression of temporomandibular disorders (TMD) in CLP patients.

Central giant cell granuloma in the posterior region of mandible mimicking a fibro-osseous lesion and hemangioma: a case report.

BACKGROUND: A central giant cell granuloma (CGCG) is a benign, proliferative, intraosseous, and non-odontogenic lesion occurring primarily in children and young adults. On the histological level, it is characterized by numerous multinucleated giant cells scattered randomly throughout a sea of spindle-shaped mesenchymal stromal cells which are dispersed throughout the fibrovascular connective tissue stroma containing areas of haemorrhage. When it comes to radiographic features, CGCG can have an array of variations, ranging from well-defined expansile lesions to ill-defined and destructive lesions, with or without expansion. CASE PRESENTATION: This case report reviews an 11-year-old Caucasian patient with a chief complaint of slow-growing swelling involving the right posterior mandibular region. The cone beam computed tomography (CBCT) revealed an ill-defined mixed lesion mimicking both fibro-osseous lesion and hemangioma. However, microscopic examination revealed multinucleated giant cells in a fibrous stroma suggestive of central giant cell granuloma. CONCLUSION: Our intent in reporting this case is to highlight the importance of thorough clinical, radiographical and histopathological examination for accurate diagnosis and therapeutic interventions as well as to emphasize the importance of taking different possibilities into consideration when examining bony swellings in the head and neck region.

The effect of tooth loss on the temporomandibular joint space: A CBCT study.

OBJECTIVE: The tooth loss has a significant impact on the positioning of the condyle in the glenoid fossa and joint spaces of the temporomandibular joint (TMJ). The aim of this study was to assess the association between tooth loss and TMJ spaces using cone beam computed tomography (CBCT) images. MATERIALS AND METHODS: This retrospective investigation involved the evaluation of CBCT images of the bilateral TMJs in a cohort of 111 individuals, comprising 68 males and 43 women. The dentition of the patients was categorized into three categories, including A (65.4%), B (19.1%), and C (16.4%), based on the Eichner index. Anterior, superior, and posterior joint spaces were then measured in sagittal views. The Kruskal-Wallis test and Mann-Whitney test were employed to identify significant differences among the three Eichner groups. RESULTS: The findings of the present study suggested that there was no statistically significant variation in the anterior joint space among different Eichner groups within the general population (p = .781). Nevertheless, the superior and posterior joint spaces exhibited statistically significant alterations, as indicated by p-values of .039 and .010, respectively. It was detected that condyles were positioned inferiorly and posteriorly in group C when compared to groups A and B. CONCLUSION: The present study indicated that greater loss of tooth-supporting zones is associated with posterior and inferior displacement of condyles. Understanding these relationships helps emphasize how crucial it is to replace missing teeth to enhance occlusion support and, in turn, stop the progression and further deterioration of temporomandibular disorders.

Dental Caries Detection and Classification in CBCT Images Using Deep Learning.

OBJECTIVES: This study aimed to investigate the accuracy of deep learning algorithms to diagnose tooth caries and classify the extension and location of dental caries in cone beam computed tomography (CBCT) images. To the best of our knowledge, this is the first study to evaluate the application of deep learning for dental caries in CBCT images. METHODS: The CBCT image dataset comprised 382 molar teeth with caries and 403 noncarious molar cases. The dataset was divided into a development set for training and validation and test set. Three images were obtained for each case, including axial, sagittal, and coronal. The test dataset was provided to a multiple-input convolutional neural network (CNN). The network made predictions regarding the presence or absence of dental decay and classified the lesions according to their depths and types for the provided samples. Accuracy, sensitivity, specificity, and F1 score values were measured for dental caries detection and classification. RESULTS: The diagnostic accuracy, sensitivity, specificity, and F1 score for caries detection in carious molar teeth were 95.3%, 92.1%, 96.3%, and 93.2%, respectively, and for noncarious molar teeth were 94.8%, 94.3%, 95.8%, and 94.6%. The CNN network showed high sensitivity, specificity, and accuracy in classifying caries extensions and locations. CONCLUSIONS: This research demonstrates that deep learning models can accurately identify dental caries and classify their depths and types with high accuracy, sensitivity, and specificity. The successful application of deep learning in this field will undoubtedly assist dental practitioners and patients in improving diagnostic and treatment planning in dentistry. CLINICAL SIGNIFICANCE: This study showed that deep learning can accurately detect and classify dental caries. Deep learning can provide dental caries detection accurately. Considering the shortage of dentists in certain areas, using CNNs can lead to broader geographic coverage in detecting dental caries.

Prevalence and Features of Maxillary Sinus Septa in Patients with Cleft Lip and Palate: Cone Beam Computed Tomography Imaging Technique.

OBJECTIVE: The development of the maxillary sinus is different in patients with cleft lip and palate (CLP) compared to non-CLP individuals. To investigate the prevalence and features of maxillary sinus septa (MSS) in patients with CLP in comparison with the non-CLP population. DESIGN: Retrospective study. INTERVENTION: Cone beam computed tomography (CBCT) evaluation. SETTING: CLP center in Shiraz faculty of dentistry, Iran. PATIENTS: A total 306 sinuses (88 cleft and 218 noncleft) on 153 images (CLP group: n = 66; control group: n = 87) were examined to determine the prevalence of septa and characterize them. MAIN OUTCOME MEASURES: Sinus septa were characterized according to height, orientation, angle, origin, and location. The chi-square test, Mann-Whitney U test, and Fisher's exact test were used for statistical analysis. RESULTS: The prevalence of septa was 28.9% and 32.1% in the CLP and control groups, respectively. No significant difference was found between the study groups in terms of prevalence, location, and orientation of MSS. The average height and angle of septa were significantly higher in the control group compared to the CLP group. Inferior origin was significantly more prevalent in the control group than in the CLP group (P = .004). CONCLUSION: There was no difference in the prevalence of MSS between patients with CLP and non-CLP individuals. However, certain features of the septa were different in patients with CLP.

Concurrent Odontogenic Keratocyst and Odontoma: Report of an Unusual and Rare Entity.

Hybrid lesions of jaws are rare entities defined as two different lesions co-occurring in the same location, with identical histopathological origin. Ameloblastoma, calcifying cystic odontogenic tumor and odontoma are among the most common lesions that have been reported to combine with other lesions. In this study, a hybrid lesion of odontogenic keratocyst (OKC) and odontoma in the mandible of a forty-five years old male reported. Additional to the rarity of this hybrid lesion, the present case had unique radiologic features, including atypical location and extension of the lesion and profound knife-edge root resorption of the teeth in the area, which was not a common feature for any of the two lesions. The surgical procedure was marsupialization to reduce the size of the lesion. As a result of the surgery, the healing of the surgical wound was uneventful. In addition, careful follow-up for the patient was conducted, which had no recurrence till now (after 15 months).

The Effect of Different Image Processing Techniques on the Measurement Accuracy of Endodontics File Length.

Statement of the Problem: Different software capabilities have been used in digital systems to increase the diagnostic quality of radiographic projections. Considering the availability of different enhancement techniques, it is necessary to determine the suitability of each technique for various diagnostic cases. There is controversy between studies over the effect of different digital enhancement techniques on the accuracy of file length measurements in endodontics. Purpose: The present in vitro study aimed to determine the effect of the software capabilities on the diagnostic accuracy to determine endodontic file lengths in photostimulable phosphor (PSP) radiographs. Materials and Method: In the present in vitro study, standard access cavities were prepared in 44 extracted human single-rooted permanent teeth. An endodontic file was placed in each root canal. PSP sensors were used for digital imaging using the parallel technique. All the images were reviewed on a same monitor; once normally with no software enhancement and once using software manipulations including pseudo-color, sharpness, emboss, and edge enhancement. The distance from the file tip to the rubber stop was measured on the images by an electronic ruler. Results: Significantly, all of the image enhancement techniques presented shorter measurements comparing to the actual length. The results revealed the significant accuracy of the measured error in the pseudo-color enhancement technique compared to other techniques. Conclusion: The results revealed significant differences between the initial measurements (the gold standard) and those made on the manipulated radiographs. In all cases, the measurements were significantly lower than the real values. Therefore, none of these digital enhancement techniques can increase the accuracy of file length measurements significantly. However, manipulation with the pseudo-color option resulted in fewer errors compared to other options and the normal images. Hence, for precise measurements of the endodontic file lengths, pseudo-color processing algorithm can be suggested when using PSP sensors.

Comparison of Superior Semicircular Canal Bone Thickness and Patterns in Unilateral and Bilateral Cleft Patients and Normal Controls: A CBCT Study.

Superior Semicircular Canal Dehiscence (SSCD) is a recently-defined developmental defect may be associated with several craniofacial anomalies such as Cleft Lip/Palate (CLP). The present study aimed to compare subjects with unilateral and bilateral CLP and normal controls in terms of Superior Semicircular Canal (SSC) bone thickness and pattern.A total of 238 Cone Beam Computed Tomography (CBCT) images were collected from 52 unilateral Cleft Lip and Palate (UCLP) subjects (104 temporal bones) and 38 Bilateral Cleft Lip and Palate (BCLP) (76 temporal bones) subjects and 148 healthy controls (296 temporal bones). The SSC bone thickness was measured twice and validated by a maxillofacial radiologist. The samples were then classified into five categories based on bone thickness: papyraceous or thin, normal, thick, pneumatized, and dehiscence. After all, the UCLP, BCLP, and normal control groups were compared concerning the SSC pattern and thickness.The results revealed no significant difference among the three groups regarding the SSC pattern and thickness based on gender. The SSC patterns (P value = .001) and SSC thickness (0.01) were strongly correlated to the cleft type. The thinnest bone thickness and the highest incidence of SSCD were observed among the subjects with BCLP.The results showed a significant association between the SSC patterns and SSC thickness and the study groups.

Association between Condylar Bone Changes and Eichner Index in Patients with Temporomandibular Dysfunction: A Cone Beam Computed Tomography Study.

Statement of the Problem: Eichner index is a dental index, which is based on the occlusal contacts between naturally existing teeth in premolar and molar regions. One controversial topic is the association between occlusal status and temporomandibular joint dysfunction (TMD) and its associated degenerative bony changes. Purpose: Through the use of cone-beam computer tomography (CBCT), the current study sought to ascertain the relationship between the Eichner index and condylar bone alterations in TMD patients. Materials and Method: In this retrospective study, the CBCT images of bilateral temporomandibular joints (TMJs) of 107 patients with TMD were evaluated. The patients' dentition was classified into three groups of A (71%), B (18.7%), and C (10.3%), according to the Eichner index. Radiographic indicators of condylar bone alterations, including as flattening, erosion, osteophytes, marginal sclerosis, subchondral sclerosis, and joint mice, were either present or absent and registered as 1 or 0, respectively. Chi-square test was used to evaluate the link between the condylar bony changes and the Eichner groups. Results: According to the Eichner index, the most prevalent group was group "A". The most prevalent radiographic finding was "flattening of the condyles" (58%). Condylar bony changes were found to be statistically related to age (p= 0.00). However, no significant relationship was found between sex and condylar bony changes (p= 0.80). There was a significant relationship between the Eichner index and condylar bony changes (p= 0.05). Conclusion: Patients with greater loss of tooth supporting zones have more condylar bony changes.

Feasibility of CBCT in Diagnosing Otosclerosis by Measuring CBCT Bone Density: A Preliminary Study.

The aim of this study was to measure cone beam computed tomography (CBCT) derived bone density of 6 anatomic points around the otic capsule in preoperative assessment of patients with clinically suspected otosclerosis, and to compare these densities with control group. CBCT images of 21 patients (34 ears, the otosclerosis group) with surgically confirmed otosclerosis and 26 patients (52 normal ears, the control group) were evaluated in this prospective study. Six regions of interest (ROI) were set manually around the otic capsule with the slice thickness of 0.3 mm. The mean CBCT bone density these regions were measured and compared in the case and control groups. In the case group, the mean CBCT bone density at the fissula ante fenestram (FAF) was significantly lower than the control group. Moreover, at the 4 points of the other ROIs (3-6) CBCT bone densities were significantly lower in the case group compared to the control group (p < 0.01). In this group, among 13 bilateral otosclerosis, 22 ears had conductive hearing loss (CHL), 4 ears had mixed hearing loss (MHL) and among 8 unilateral otosclerosis, 5 ears had CHL, 3 ears had MHL. Our study showed the mean CBCT bone density of ROIs 1 and 6 were correlated with the average air-bone gap in the bilateral and unilateral otosclerosis group, respectively. Quantitative evaluation of CBCT with a slice thickness of 0.3 mm can be used as a suitable tool for diagnosis and follow-up of otosclerosis in temporal bone.

Effects of Radiofrequency Electromagnetic Fields Emitted from Mobile Phones and Wi-Fi Router on the Growth Rate and Susceptibility of Enterococcus faecalis to Antibiotics.

Background: During the last decade, people have been dramatically exposed to radiation emitted from widely-used radiofrequency electromagnetic fields (RF-EMF) generating devices. Objective: This study aimed to evaluate the effects of exposure to RF-EMF emitted from smart phones and Wi-Fi routers on the growth rate and antibiotic sensitivity of Enterococcus faecalis (E. faecalis) as a pathogen in the root canals of teeth. Material and Methods: In this experimental study, E. faecalis ATCC 19115 was used, characterized and confirmed by morphological and biochemical tests. Antibiotic susceptibility test was measured for several common antibiotics. To perform antibiotic susceptibility tests, disk diffusion (Kirby-Bauer) method on Mueller-Hinton agar plates was used before and after exposure to RF-EMFs emitted from a commercial Wi-Fi router or a mobile phone simulator. Moreover, we measured the optical density at 625 nm after different exposure times using a calibrated UV-visible spectrophotometer to evaluate the effect of RF-EMF exposure on the bacterial growth rate. Results: Exposure to RF-EMF significantly altered the antimicrobial sensitivity of the E. faecalis. While, the susceptibility of the bacteria decreased significantly after 6 h of exposure, longer exposure time (e.g. exposure for 24 h) increased the susceptibility of the bacteria to all antibiotics. Furthermore, it was found that the bacteria tended to regress to their early state. Moreover, the non-exposed E. faecalis showed a slower growth rate than the bacteria exposed to RF-EMFs. Conclusion: Exposure to RF-EMF emitted by Wi-Fi routers or mobile phone simulator can significantly change the antibiotic susceptibility and growth rate of E. faecalis.

Are of Osteomeatal Complex Variations Related to Nasolacrimal Canal Morphometry.

INTRODUCTION: Due to the close anatomic relationship between paranasal structures and NLC, the morphometric measure of the nasolacrimal canal (NLC) could be affected by the osteomeatal complex (OMC) anatomical variations. The present study aimed to assess the effect of OMC variations on the NLC morphometric features using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: This cross-sectional study consisted of CBCT images of 150 subjects in the case group with at least one OMC variation and 40 cases in the control group without any OMC variation within the age range of 18-50 years. The presence of the OMC variations, including agger nasi, nasal septum deviation, concha bullosa, Haller cells, paradoxical middle turbinate, and pneumatization of the uncinate process, was evaluated in each patient. The NLC morphometric measurements were performed and compared between the case and control groups. RESULTS: The middle anteroposterior diameter and middle sectional area of NCL were significantly higher in patients with OMC variations, as compared to that in the control group. The NLC volume was significantly higher in patients with agger nasi, nasal septum deviation, concha bullosa, and pneumatization of the uncinate process, as compared to that in the control group. Nonetheless, no significant difference in NLC angulation with the nasal floor or Frankfurt horizontal plane was observed in the presence of each OMC variation. CONCLUSIONS: As evidenced by the obtained results, a higher volume of the canal was revealed in the presence of some of the OMC variations. Therefore, it can be suggested that OMC variations cannot be a predisposing factor in cases with primary acquired nasolacrimal duct obstruction.

A Radio-Odontometric Analysis of Sexual Dimorphism in First Molars Using Cone-Beam Computed Tomography.

OBJECTIVE: Different techniques for sex prediction are developed and used in the forensic medicine field. One of these methods is based on the teeth morphometry. The aim of the present study was to evaluate the degree of sex determination of the maxillary and mandibular first molar teeth in cone beam computed tomography images. METHOD AND MATERIALS: This study was carried out on cone beam computed tomography images of 100 men and 100 women with a mean age of 21.28 ± 2.47 years. The roof, floor and height of pulp chamber, as well as marginal enamel thickness and dentin thickness at the height of contour, tooth width, and crown length were measured. Student t test and discriminant analysis were applied to assess the differences in the measured parameters between men and women. RESULTS: According to the present study, the maxillary first molar was more dimorphic than the mandibular teeth. The accuracy of sex identification of mandibular and maxillary first molar tooth was 84% and 77%, respectively. The mesiodistal measured variables were more accurate in sexual differentiation than the buccolingual ones. For sex differentiation, the most dominant variables for maxillary and mandibular first molar teeth were crown height and dentin thickness, respectively. CONCLUSIONS: The first molar tooth showed an acceptable level of sex determination accuracy based on the odontometric measurements.

Evaluation of Maxillary Sinus Characteristics in Patients With Cleft Lip and Palate Using Cone Beam Computed Tomography.

OBJECTIVES: The detection of anatomical variation impairments in patients with cleft lip and palate (CLP) is crucial in combined orthodontic and maxillofacial surgical treatments. Therefore, this study aimed at evaluating the anatomical maxillary sinus characteristics, nasal septum deviation (NSD), and mucosal thickening of the maxillary sinus in patients with CLP using cone beam computed tomography (CBCT). DESIGN: The CBCT images were classified into 3 groups of unilateral cleft lip and palate (UCLP; n = 40), bilateral cleft lip and palate (BCLP; n=14), and noncleft (control; n = 54). Subsequently, the maxillary sinus linear dimensions were assessed. Height, width, depth, infundibulum height, and ostium width were assessed as quantitative measures, whereas nasal septum deviation and mucosal thickening were assessed as qualitative measures. One-way analysis of variance and χ2 tests were utilized to identify any significant differences among the groups regarding the aforementioned variables. RESULTS: Significant differences were observed among the groups regarding maxillary sinus height and depth, NSD, and mucosal thickening. Moreover, UCLP and BCLP groups showed higher incidence of NSD and mucosal thickening. However, the size of maxillary sinus height and depth was lower in the UCLP and BCLP groups. CONCLUSION: The results showed that BCLP and UCLP groups obtained lower maxillary sinus height and depth compared to the control group. On the other hand, incidence of the NSD and mucosal thickening was significantly higher in UCLP and BCLP groups than those in the control group.

Evaluation of the Prevalence of Atherosclerosis Within the Course of Internal Carotid Artery in Cone Beam Computed Tomography Images.

The aim of the present study was to retrospectively evaluate the gender-related and age-related prevalence and severity of calcifications within the segments of the internal carotid artery in cone beam computed tomography (CBCT). By using a documented visual scale, out of 400 CBCT examinations a total of 304 CBCT scans of adult patients over 40 years old were evaluated as to the prevalence and severity of intracranial calcifications within the segments of the internal carotid artery. Calcifications were found in 117 CBCT scans. These calcifications were detected along the extracranial (C1: 53%), petrous (C2: 22.2%), Lacerum (C3:27%), cavernous (C4: 94%), and ophthalmic-clinoid (C5/C6: 65%) segments. The Friedman test showed significant differences in the severity of calcifications among the internal carotid artery segments. The McNemar test showed no significant differences between calcifications on the right or left side segments. The Chi square test showed no significant differences in the prevalence of calcifications between men and women; it also showed that the prevalence of calcifications increased with increase in age (P < 0.05). In this study, the frequency and severity of calcifications decreased throughout the C4, C5/C6, and C1 segments in a descending order; moreover, an increased incidence of calcifications by increase in age was documented irrespective of gender.

Comparison of the Accuracy of CBCT Images and Apex Locator in Detection of External Root Resorption with Perforation.

Statement of the Problem: Perforation within external root resorption (ERR) lesions dra-matically affects the prognosis of the involved roots. Failure to diagnose perforation under-mines treatment; therefore, early detection of these lesions is of great importance. The cone-beam computed tomography (CBCT) images and electronic apex locators (EAL) are reliably used to detect root perforations. Purpose: In this in vitro study, we compared the EAL findings with the results obtained by the CBCT images for the detection of perforations within ERR lesions. Materials and Method: This cross sectional study included 160 extracted anterior human teeth. The teeth were categorized into four groups including teeth with intact root, teeth with ERR, teeth with ERR and 0.5 mm perforation, and teeth with ERR with 1 mm perforation. The presence of perforations was compared by CBCT images and root EAL. Results: The sensitivity of CBCT scans in detecting 0.5 mm and 1 mm root perforations was 100% and 97.5%, respectively, while the sensitivity of the EAL was 10% and 27.5% in de-tecting 0.5 mm and 1 mm root perforations, respectively( with the ±0.5mm range of error). For detecting intact and teeth with ERR, the specificity of CBCT scans was 100% and 95%, respectively, and for EAL, it was 100% for both. Poor agreement was found between the two techniques (kappa=-0.025). Conclusion: CBCT scans were more sensitive and specific than EAL scans for detecting perforations in non-obturated root canals in this study.

A cloud-fog software architecture for dental CBCT dose monitoring using the DICOM structured report: Automated establishment of DRL.

PURPOSE: The diagnostic reference level (DRL) has been established to optimize the diagnostic methods and reduce radiation dose during radiographic examinations. The aim of this study was to present a completely new solution based on Cloud-Fog software architecture for automatic establishment of the DRL values during dental cone-beam computed tomography (CBCT) according to digital imaging and communications in medicine (DICOM) structured reports. METHODS AND MATERIALS: A Cloud-Fog software architecture was used for automatic data handling. This architecture used the DICOM structured reports as a source for extracting the required information by fog devices in the imaging center. These devices transferred the derived information to the cloud server. The cloud server calculated the value of indication-based DRL in dental CBCT imaging based upon the parameters and adequate quantities of the absorbed dose. The feedback of DRL value was continuously announced to the imaging centers in 6 phases. In each phase, the level of the dose was optimized in imaging centers. RESULTS: The DRL value was established for 5-specific indications, including third molar teeth (511 mGy.cm2), implant (719 mGy.cm2), form and position anomalies of the tooth (408 mGy.cm2), dentoalveolar pathologies (612 mGy.cm2), and endodontics (632 mGy.cm2). The determination of the DRL value in each phase revealed a downward trend until stabilization. CONCLUSION: The new solution presented in this study makes it possible to calculate and update the DRL value nationally and automatically among all centers. Also, the results showed that this approach is successful in establishing stabilized DRL values.

Cone Beam Computed Tomography Analysis of Sphenoid Sinus Pneumatization and Relationship with Neurovascular Structures.

BACKGROUND: The sphenoid sinus is considered as the most variable pneumatized structure of the skull. PURPOSE: The aim of the present study was to determine the prevalence of the Onodi cell as well as to evaluate the relationship between the sphenoid sinus type of pneumatization and the presence of surrounding neurovascular protrusion using cone beam computed tomography (CBCT). METHODS: The CBCT images of 500 patients/996 sides [203 males (40.6%) and 297 females (59.4%)] were analyzed in this study. The type of sphenoid sinus pneumatization, prevalence of internal carotid artery (ICA) and optic nerve (ON) protrusion and dehiscence, and also the frequency of Onodi cell were assessed. RESULTS: The percentages of the conchal, presellar, sellar, postsellar (a), and postsellar (b) types of pneumatization were 1%, 11.5%, 35.5%, 38.9%, and 13.1%, respectively. The more the sphenoid sinuses pneumatized, the greater the frequency of ON and ICA protrusion and dehiscence of their wall to the sinus. The prevalence of Onodi cell was 38.8%. A significant correlation was found between ON dehiscence and the presence of Onodi cells. CONCLUSION: The present study demonstrated a significant relationship between the sinus type and frequency of neurovascular protrusions. Therefore, the sphenoid sinus extent of pneumatization might be useful in predicting the risk of iatrogenic damage to the surrounding structures.

Sex classification of first molar teeth in cone beam computed tomography images using data mining.

OBJECTIVE: The teeth have been used as a supplementary tool for sex differentiation as they are resistant to post-mortem degradation. The present study aimed to develop a new novel informatics framework for predicting sex from linear tooth dimension measurements achieved from cone beam computed tomography (CBCT) images. METHOD AND MATERIALS: A clinical workflow using different machine learning methods was employed to predict the sex in the present study. The CBCT images of 485 subjects (245 men and 240 women) were evaluated for sex differentiation. Nine parameters were measured in both buccolingual and mesiodistal aspects of the teeth. We applied our dataset to Naïve Bayesian (NB), Random Forest (RF), and Support Vector Machine (SVM) as classifiers for prediction. Genetic feature selection was used to discover real features associated with sex classification. RESULTS: The 10-fold cross-validation results indicated that NB had higher accuracy than SVM and RF for sex classification. The genetic algorithm (GA) indicated that the model could fit the data without using the enamel thickness and pulp height. The average classification accuracy of our clinical workflow was 92.31 %. CONCLUSION: The results showed that NB was the best method for sex classification. The application of the first molar teeth in sex prediction indicated an acceptable level of sexual classification. Therefore, these odontometric parameters can be applied as an additional tool for sex determination in forensic anthropology.