Cone Beam Computed Tomography Findings Research Articles

Asymmetric lambda sign of the second tarsometatarsal joint on axial weight-bearing cone-beam CT scans of the foot: preliminary investigation for diagnosis of subtle ligamentous Lisfranc injuries in a cadaveric model.

Subtle Lisfranc joint injuries remain challenging to diagnose. Although of questionable accuracy, the current gold standard to assess these injuries is through bilateral weight-bearing radiography. However, weight-bearing cone beam-computed tomography (CBCT), providing clearer visualization of bony landmarks, can also be utilized for evaluation. This study aims to establish the hypothesis that a specific weight-bearing CBCT finding (asymmetric lambda sign) can serve as an independent indicator of a subtle Lisfranc injury. Weight-bearing CBCT images of 24 match-paired cadaveric legs were acquired, initially intact, and then following sequential dissection of each aspect (dorsal, interosseous, and plantar ligaments, respectively) of the Lisfranc ligamentous complex (LLC). All scans were taken in non- (NWB, 0kg), partial- (PWB, 40kg), and full-weight-bearing (FWB, 80kg) manners. The lambda sign was then inspected axially for asymmetry (positive sign) by identifying three symmetrical joint spaces created between the medial cuneiform and the second metatarsal base (C1-M2), the medial and middle cuneiform (C1-C2), and the second metatarsal base and middle cuneiform (M2-C2). A positive sign was observed in 25.6% (221/864) of all studies. Most notably, the fully dissected specimens demonstrated an asymmetric lambda sign in 33.3%, 72.2%, and 83.3% in NWB, PWB, and FWB conditions, respectively. The inter- and intra-observer reliability kappa value was calculated to be 0.843 and 0.912. An asymmetric lambda sign is a simple and useful indicator for a complete LLC injury in PWB and FWB conditions using a cadaver model.

Prevalence of soft tissue calcifications in cone beam computed tomography images in the region of head and neck

Objective: to evaluate the prevalence of calcifications in the soft tissues of the cervical-facial region using cone beam computed tomography (CBCT) images. Material and Methods: two hundred and ten CBCT exames was analyzed by 01 examiner previously trained, with fild of view (FOV) of 16 x 13 cm and voxel of 0.25 mm, in ICAT Vision software (Imaging Science International, Hatfield, PA, USA) in coronal, axial and sagittal sections. The following calcifications were evaluated: tonsiloliths, sialolites, calcification of the styloid complex, calcified carotid atheromas, calcifications in laryngeal cartilages, calcified lymph nodes and osteoma cutis. The findings were tabulated according to the total of the sample, related to the gender, age group of the individuals. Results: Calcification of the styloid complex was the most frequent in the sample studied in both genres (39.04%), followed by the presence of tonsiloliths (19.52%), and calcified lymph nodes (6,67%). Conclusion: calcifications are frequent radiographic findings in CBCT and important for the diagnosis of some possible pathologies that do not present clinical symptoms.KEYWORDSCone-beam computed tomography; Prevalence; Soft tissue calcification.

Identification of Specific Panoramic High-Risk Signs in Impacted Third Molar Cases in Which Cone Beam Computed Tomography Changes the Treatment Decision

The aim of this study was to investigate the treatment decisions of oral-maxillofacial surgeons in the management of impacted lower third molars (M3s) according to panoramic radiography (PR) and cone beam computed tomography (CBCT) risk analysis. Ten surgeons analyzed 40 deliberately selected M3 cases showing 1 or more panoramic high-risk signs: 1) darkening of the root, 2) interruption of the white line, 3) diversion of the inferior alveolar canal (IAC), 4) narrowing of the IAC, and 5) 2 or more signs occurring simultaneously (including darkening and/or interruption of the IAC). After evaluating the PR images, the observers analyzed the patients' CBCT images. The treatment decision (extraction vs coronectomy) and surgical technique (number of planned tooth sections) were recorded. On the CBCT coronal slices, direct contact between the M3 and IAC, together with narrowing and/or fenestration of the IAC, was observed most frequently when 2 or more panoramic signs were seen simultaneously on the PR images (odds ratio [OR], 7.2; P=.021). CBCT findings led to a significant decrease in the number of coronectomy decisions (23% vs 14.5%, P=.002), which was most prominent in the groups showing panoramic signs of darkening (approximately 50%, P=.007) and narrowing (approximately 66%, P=.044). A significant number of extraction decisions were modified to coronectomy when 2 or more panoramic signs occurred together (OR, 7.9; P<.001). However, there were no significant differences regarding the number of planned hypothetical tooth sections. The results showed that the surgeons' confidence in the treatment decision increased after CBCT imaging, resulting in fewer coronectomy decisions. CBCT information that changed a previous coronectomy decision to extraction was most frequently observed in cases showing darkening and narrowing PR signs. The chance of changing an extraction decision to a coronectomy decision after evaluating the patient's CBCT images was the highest when 2 or more PR signs were observed simultaneously.

Sinus floor elevation or referral for further diagnosis and therapy: A comparison of maxillary sinus assessment by ENT specialists and dentists using cone beam computed tomography.

To compare ear, nose, and throat (ENT) specialists and dentists assessing health or pathology of maxillary sinuses using cone beam computed tomography (CBCT). Two ENT specialists and two oral surgeons assessed 100 CBCT datasets of healthy patients referred for dental implant placement in the posterior maxilla and decided on the possibility of sinus floor elevation or the necessity for further diagnostic examinations based solely on radiographic findings. Inter-rater agreements within the same specialty were calculated with Cohen's kappa and overall agreements with Fleiss kappa, and factors influencing the decisions taken were evaluated using regression analyses. The correlation between all four raters was generally fair to moderate. The intra-specialty comparison showed a lower correlation between dentists than between ENT specialists. Absence of membrane thickening and total or subtotal sinus opacification showed the highest predictive value for a consensus in favor of sinus floor elevation and ENT referral, respectively. Flat membrane thickening with an irregular surface morphology was associated with disagreement between the examiners. Dome-shaped membrane thickenings were often considered as to be referred by dentists but not by ENTs. The assessment of maxillary sinuses using CBCT imaging exhibited unsatisfactory agreement between ENT specialists and oral surgeons. Referral guidelines based on accidental CBCT findings that aim to diagnose relevant sinus pathologies early and avoid unnecessary diagnostics and/or therapies are needed, and an initial proposal for such recommendations is provided. Further research on correct interpretation of sinus findings and a validation of the present recommendations are required.

Evaluation of osteoarthritic changes in the temporomandibular joint and their correlations with age: A retrospective CBCT study.

Cone-beam computed tomography (CBCT) enables the radiographic examination and evaluation of osseous changes in the temporomandibular joint (TMJ). The aim of this study was to determine the prevalence of various bony changes in TMJ in patients from a wide age range as well as to evaluate the CBCT findings of TMJ osteoarthritis (OA) and correlate them with age. The study included the CBCT images of 150 patients (43 males and 107 females) who were refferred to the Department of Dentomaxillofacial Radiology for the evaluation of TMJs. Each TMJ was evaluated separately for the presence of any osseous changes in the condylar head or articular fossa/eminence, and for joint space narrowing. The mean age of the sample was 37.26 years (range: 10-90 years). A total of 101 (67.3%) patients presented 1 or more osseous changes. No significant differences were found between the right and left TMJs concerning the prevalence rates of osseous changes. Significant differences were found in the mean ages with regard to the absence and presence of the following findings: condylar erosion, osteophytes, loose bodies, erosion in the articular fossa, and joint space narrowing. Degenerative changes in TMJ may reflect an age-related bone remodeling process. Older patients may have more common findings of OA, such as condylar and articular erosion, osteophytes, loose joint bodies, and joint space narrowing.

"Radiographic demonstration of association of ubernaculum Dentis (Gubernaculum tract) in odontogenic cysts and tumors"-A CBCT finding.

Spectrum of lesions that occur in the jaws have a cyst-like radiographic appearance. These lesions may be odontogenic or non-odontogenic and are often difficult to differentiate them on the basis of their clinical, radiographic features alone. Among odontogenic lesions without mineralization, ameloblastomas, odontogenic keratocysts, and dentigerous cysts can all appear as well-defined, unilocular, well-corticated, lucent lesions that can mimic with non-odontogenic cysts and tumors like nasopalatine duct cyst, aneurysmal bone cyst, central giant cell granuloma, hemangioma and so on. So understanding the pathogenesis of these lesions become the most imperative criteria for determining the additional investigations and treatment protocol. We hereby discuss 8 diagnosed cases of odontogenic and non-odontogenic jaw lesions, which were retrospectively visualized in cone beam computed tomography (CBCT), and an association of gubernaculum tract (cord) with odontogenic origin lesions was demonstrated.

Comparison of panoramic radiograph and cone beam computed tomography findings for impacted mandibular third molar root and inferior alveolar nerve canal relation.

This study was aimed at determining the specific signs of close relationship between impacted mandibular third molar (IMTM) root and inferior alveolar nerve (IAN) canal as visualised on digital panoramic radiograph or orthopantomograph (OPG) which should indicate as well as contraindicate the need for cone beam computed tomography (CBCT) imaging based on hierarchical model of Fryback and Thornbury. The sample consisted of 120 individuals (200 IMTM) who had undergone OPG as well as CBCT imaging as preoperative radiographic evaluation before surgical extraction. On panoramic radiographs; Rood and Sheehab's radiographic signs of IMTM root and IAN canal, impacted third molar position based on Winter's classification and depth of impaction based on Pell and Gregory's classification were evaluated. On CBCT; presence/absence of corticalization and the status of the buccal and lingual cortices (thinning/perforation) were evaluated. These findings of OPG were compared to CBCT findings to determine the better modality based on hierarchical model of Fryback and Thornbury. Statistically significant association was found between radiographic signs of Rood and Sheehab such as 'no relation' and 'superimposition' on OPG and presence of corticalization between IMTM root and IAN canal on CBCT. Statistically significant association was also found between 'mesioangular' and 'vertical' positions of Winter's classification as well as 'class 1A' of Pell and Gregory's classification of IMTM on OPG and presence of corticalization on CBCT. CBCT was found to be having lesser variance and greater F value as compared to OPG for evaluation of IMTM. On OPG; Rood and Sheehab's radiographic signs such as 'no relation' and 'superimposition', Winter's 'mesioangular' and 'vertical' and Pell and Gregory's 'Class 1A' are not indicative for CBCT examination before surgical extraction is attempted. On OPG; Rood and Sheehab's radiographic signs such as interruption of white line, darkening of root, darkening of canal, deflection of root, narrowing of canal as well as diversion of canal are all frequently associated with absence of corticalization between IMTM root and IAN canal and hence require CBCT examination before surgical extraction is attempted so that post-operative neurological complications can be minimised. Also, Winter's horizontal, distoangular and others as well Pell and Gregory's classes 1B,1C,2A,2B,2C,3A,3B,3C are indicative for CBCT examination before surgical extraction is attempted. Fryback and Thornbury model-based comparison proves that CBCT is a better radiographic modality as compared to OPG for evaluation of IMTM relation with IAN canal.

Cone Beam CT Evaluation of Bilateral Maxillary Sinus Hypoplasia with Unilateral Mandibular Hypertrophy

Maxillary sinus hypoplasia (MSH) is a rare condition characterized by underdevelopment or decrease in the volume of the maxillary sinus. It is thought that MSH may be embryological in origin but acquired etiologies have also been discussed in the literature. MSH is usually detected upon radiographic examination of the maxillofacial area. Three types have been described based on variations in sinus anatomy. A case of bilateral maxillary sinus hypoplasia with concurrent hemimandibular hypertrophy is presented, and pertinent clinical and cone beam computed tomography findings are reported.

Agreement between cone-beam computed tomography and functional endoscopic sinus surgery for detection of pathologies and anatomical variations of the paranasal sinuses in chronic rhinosinusitis patients: A prospective study.

PurposeThe diagnosis of chronic rhinosinusitis requires a comprehensive knowledge of the signs and symptoms of the disease and an accurate radiographic assessment. Computed tomography (CT) is the superior imaging modality for diagnosis of chronic rhinosinusitis. However, considering the lower dose and higher resolution of cone-beam computed tomography (CBCT) compared to CT, this study aimed to assess the agreement between the findings of CBCT and functional endoscopic sinus surgery (FESS).Materials and MethodsThis descriptive prospective study evaluated 49 patients with treatment-resistant chronic rhinosinusitis who were candidates for FESS. Preoperative CBCT scans were obtained before patients underwent FESS. The agreement between the CBCT findings and those of FESS was determined using the kappa correlation coefficient. The frequency of anatomical variations of the paranasal sinuses was also evaluated on CBCT scans.ResultsSignificant agreement existed between pathological findings on CBCT scans and those of FESS, such that the kappa correlation coefficient was 1 for mucosal thickening, 0.644 for nasal deviation, 0.750 for concha bullosa, 0.918 for nasal polyp, 0.935 for ostiomeatal complex (OMC) obstruction, and 0.552 for infundibulum thickening. Furthermore, 95.9% of patients had 1 or more and 79.6% had 2 or more anatomical variations, of which nasal deviation was the most common (67.3%).ConclusionConsidering the significant agreement between the findings of CBCT and FESS for the detection of pathological changes in the paranasal sinuses, CBCT can be used prior to FESS to detect chronic rhinosinusitis and to assess anatomical variations of the OMC.

Validity of Cone-beam Computed Tomography in Assessment of Morphological Bony Changes of Temporomandibular Joints

The aim of the current study was to correlate the clinical symptoms that are associated with temporomandibular disorder (TMD) to the osseous changes occurring in the affected temporomandibular joint (TMJ), as detected by cone-beam computed tomography (CBCT). The clinical data of patients that presented with TMJ symptoms was collected and correlated with the CBCT findings for the same patients. Patient recruitment took place over a 1-year period in the Oral and Maxillofacial Surgery and Oral and Maxillofacial Radiology department of the same academic institution. There was a limited mouth opening (MO) (<3 cm). More importantly, there was a statistically significant positive relation between pain and loss of cortication. There was no significant correlation between CBCT findings consistent with TMJ degeneration and clinical symptoms. Cone-beam computed tomography evaluation of the TMJ is important for providing information about the state and level of TMJ degeneration if any. However, clinical findings should be the most important factor when considering management options for symptomatic TMJ.

Evaluation of the relationship between appearances of the lingual foramen on panoramic radiography and cone-beam computed tomography

The aim of this retrospective study is to determine the level of visibility of the lingual foramen in panoramic radiography using cone-beam computed tomography (CBCT) as a reference tool. A total of 200 patients (111 females and 89 males) were included in the study. Cross-sectional CBCT images of the mandible in the midline were used to locate and define the orifice and diameter of each lingual canal that was detected. The appearance of the lingual foramen in the anterior mandible in panoramic radiography was assessed using a five-point ordinal scale. Descriptive statistics including tables and graphs were used. The correlation between CBCT and panoramic radiography findings were analyzed using Chi-square tests. The lingual foramen was found to be located most frequently in the mandibular midline, above the genial tubercle (78.5%). A narrow-diameter type was found to occur most frequently (56.5%). A prominent genial tubercle was the most commonly found type (57.5%). The lingual foramen could be definitively identified in panoramic radiographs in only 8 cases (4%), while a high degree of probability was found in 25 cases (12.5%). The lingual foramen appears wider and therefore more distinctive in panoramic radiographs when the angulation of the lingual canal is less than 20° to the ground plane. Radiological evaluation with panoramic radiographs alone may lead to inadequate assessments prior to surgical procedures involving the anterior mandible. Clinicians may consider using three-dimensional imaging for procedures with a risk of hemorrhagic and neurosensory complications such as dental implant placement in the anterior mandible.

Presurgical assessment of alveolar ridge dimensions before dental implant procedures by OPG&amp;CBCT – A comparative study based on fryback &amp; thornbury model

Background and Aims: Replacing missing teeth is one of the most common challenges faced by the dental surgeon. The invention of dental implants has brought about a great change in successfully delivering a fixed prosthesis to the patient. Precise radiographic assessment of available alveolar bone is of prime importance for dental implant placement. Panoramic radiograph provides an overview of the jaw bones and is considered adequate in the initial evaluation of the implant site; however, they do not provide the buccolingual dimension of the implant site. CBCT provides volumetric imaging with the ability to visualize the imaged region in virtually any plane. The objective of this study was to compare panoramic radiography (OPG) with cone-beam computed tomography (CBCT) for pre-surgical implant site evaluation. Materials and Methods: A total of 150 potential implant sites in 94 patients who were subjected to OPG and CBCT imaging previously were selected for the study. The height, width, and length of the available bone were measured for all the implant sites (except bone width which was measured on CBCT alone). Out of these, OPG & CBCT findings of 60 potential implant sites were evaluated by comparison with the surgical gold standard dimensions of actual dental implant placed. A comparison of all the values obtained with the two imaging modalities was done and the data was tabulated for statistical analysis. Results: The mean value of bone height using OPG and CBCT were found to be 12.15 mm and 11.99 mm, respectively. The mean value of the length of the edentulous jaw segment using OPG and CBCT was found to be 8.10 mm and 8.98 mm respectively. The mean value of the width of the crestal bone below the height of the crest using CBCT was found to be 5.46 mm. Conclusion: The overall results suggested that CBCT is better in depicting the bone height and bone width as compared to OPG; however, the length of the edentulous jaw segment is better depicted by OPG as compared to CBCT.

Evaluation of the Relationship of Dimensions of Maxillary Sinus Drainage System with Anatomical Variations and Sinusopathy: Cone-Beam Computed Tomography Findings

Objective: The aim of this study was to evaluate the correlation between the length of the infundibulum and ostium height with the anatomic variations of osteomeatal complex (OMC) and sinus pathology using cone-beam computed tomography (CBCT). Methods: CBCT images of 204 patients (408 maxillary sinuses) were evaluated retrospectively. The height of the ostium and the length of the infundibulum were measured. The presence of maxillary sinus pathology, nasal septal deviation, Haller cells, concha bullosa, and sinus septa were analyzed. The correlation between the size of the maxillary sinus drainage system and anatomic variations was compared using the t test, Fisher’s exact test, and χ² test. The effect of tooth loss on the length of the infundibulum and ostium height was also analyzed using ANOVA. Results: The height of the ostium and the maximal septal deviation angle were found to be significantly greater in males (p < 0.05). As ostium height increased, the presence of maxillary sinus septa increased (p < 0.05). No statistically significant association was detected between other variations and the length of infundibulum or ostium height. The relationship between tooth loss and both the length of the infundibulum and ostium height were found to be insignificant (p > 0.05). Conclusions: Radiographic examination, especially on CBCT images, is important for an evaluation of maxillary sinuses. here, we demonstrated a significant relationship between ostium height and the presence of maxillary sinus septa. However, it was found that nasal septal deviation, concha bullosa, Haller cells, and other sinusopathies did not have a major effect on the size of the maxillary sinus drainage system.

A comparison of the cone beam computed tomography findings in medication-related osteonecrosis of the jaws related to denosumab versus bisphosphonates: an observational pilot study.

The aim of this study was to compare the radiographic abnormalities on cone beam computed tomography (CBCT) in patients with medication-related osteonecrosis of the jaws (MRONJ) related to denosumab use versus bisphosphonate use. The study included 34 consecutive patients with MRONJ who had a history of exclusive use of denosumab (n = 17) or bisphosphonates (n = 17) and had undergone CBCT for determination of extent of disease. Demographic data of the patients were collected. Differences in radiologic characteristics between patients with denosumab-related osteonecrosis of the jaws (DRONJ) and those with bisphosphonate-related osteonecrosis of the jaws (BRONJ) were scored and studied on CBCT. In patients with DRONJ, sequestra (P = .015) and lysis of the cortical border of the jaw (P = .033) were significantly less common than in patients with BRONJ. Subperiosteal bone formation did not differ between the groups (P = .545). There was no association between stage of disease and duration of drug therapy or duration of symptoms for either medication group. The radiologic features of DRONJ may be different from those of BRONJ with regard to the presence of sequestra and cortical lysis and might, therefore, be improperly diagnosed. Underestimation and undertreatment of DRONJ may potentially lead to progression of disease and, thus, make treatment more difficult.

Evaluation of skeletal changes associated with surgically rapid palatal expansion without pterygomaxillary separation

IntroductionTo evaluate skeletal and nasal volume changes before and after surgery in surgically assisted rapid palatal expansion (SARPE) without pterygomaxillary separation and compare the dental changes by digital model analysis and radiographic analysis. Setting and samplePopulation A total of 18 patients (10 females and 8 males) aged 15–33 years and with completed skeletal development, who were referred to Oral and Maxillofacial Surgery Department, Dentistry Faculty, Istanbul University and who had SARPE indication were included in the study. Materials and methodsSkeletal changes, lower nasal volume, transverse diameters of bony nasolacrimal duct and dental changes have been evaluated by using Cone beam computed tomography (CBCT) before and 6 months after the surgery. CBCT data was determined by Mimics v.18.01. Dental changes have been also evaluated by digital model analysis program ‘Shape Orthoanalyzer’ and the data are compared with those obtained using CBCT. ResultsThe results obtained from dental measurements made using CBCT and those obtained using scanning three-dimensional (3D) models were consistent with each other. CBCT demonstrated that lower anterior nasal volume and transverse diameters of bony nasolacrimal duct showed statistically significant increase before and after the surgery. ConclusionsAccording to the study findings, SARPE without pterygomaxillary separation was noted to be an effective procedure. Lower nasal volumes were increased and the maxilla expanded in the transverse direction in all patients. Dental evaluations that were performed in this digital model analysis also supported our findings in CBCT. Transverse diameters of the bony nasolacrimal duct were shortened at all patients.

Idiopathic Osteosclerosis of the Jaws in Turkish Subpopulation: Cone-Beam Computed Tomography Findings

Objective: Idiopathic osteosclerosis (IO) was defined as an asymptomatic, incidental radiographic finding of intrabony sclerosis with unknown origin. The purpose of this retrospective study is to evaluate IO distribution, location, relationships and radiographic features by cone beam computed tomography (CBCT) in Turkish subpopulation. Materials and Methods: The study group consisted of CBCT images of 279 individuals, 140 females and 139 males aged 20-69. In received images IO distribution, location in the jaws, dental and cortical relationships, shape and internal structure were evaluated. In axial and cross-sections superoinferior (SID), mesiodistal (MDD) and buccolingual (BLD) distances of IO were measured. The data was compared with age groups and gender. Results: Ninety-two IO in 75 individuals were detected with 26.9% distribution rate. There was a higher prevalence in mandible (82.6%) than maxilla (17.4%). The most frequently involved area was posterior mandible (43.4%). No statistically significant difference in the distribution of IO was found between genders (p˃0.05). There was a higher prevalence among young group than middle-aged and above middle-aged groups (p=0.026). According to relation of IO with dental roots separate IO (76.1%) was the most frequent relationship. Seven IO (7.6%) were detected as not related with any cortical structure. Mean SID, MDD and BLD were recorded 5.58; 4.80 and 4.18 mm respectively. Conclusion: IO was detected at a high rate in Turkish subpopulation. CBCT was found as an efficient method to evaluate radiographic features, relationships and location of IO within the jaws before surgical and orthodontic operations.

Transbronchial Biopsy Using an Ultrathin Bronchoscope Guided by Cone-Beam Computed Tomography and Virtual Bronchoscopic Navigation in the Diagnosis of Pulmonary Nodules

Background: Transbronchial biopsy is a safe diagnostic approach for patients with peripheral pulmonary lesions; however, the diagnostic yield is low. Objectives: This study was conducted to evaluate the feasibility and diagnostic yield of transbronchial biopsy using the combination of an ultrathin bronchoscope, virtual bronchoscopic navigation (VBN), and cone-beam computed tomography (CBCT). Methods: Patients with peripheral pulmonary lesions, no >30 mm, with the responsible bronchus, were prospectively included. An ultrathin bronchoscope and biopsy forceps were advanced to the target bronchus under VBN, 2D-fluoroscopy, and CBCT. We categorized the CBCT findings before biopsy into 3 types according to positions of the target lesion and forceps (CBCT target-forceps sign). In type A, the forceps reached the inside of the target lesion. In type C, the forceps could not reach the lesion. When the CBCT findings could not be categorized into either type A or C, the sign was categorized as type B. Results: Although the target lesions were invisible by conventional C-arm fluoroscopy in 29 patients, CBCT visualized all 40 lesions. The overall diagnostic yield was 90.0%, and diagnostic yields for malignant and benign lesions were 92.0 and 86.7%, respectively. Diagnostic yields for CBCT target-forceps sign types A, B, and C were 100, 75.0, and 0%, respectively. Four undiagnosed patients proceeded to other diagnostic procedures based on the CBCT target-forceps sign (type B: n = 2, type C: n = 2) and were correctly diagnosed without delay. Conclusions: Transbronchial biopsy using an ultrathin bronchoscope guided by CBCT and VBN showed a very high yield in the diagnosis of pulmonary nodules.

Diversion of the mandibular canal: Is it the best predictor of inferior alveolar nerve damage during mandibular third molar surgery on panoramic radiographs?

PurposeThe aim of this study was to evaluate the relationship between the mandibular canal and impacted mandibular third molars using cone-beam computed tomography (CBCT) and to compare the CBCT findings with signs on panoramic radiographs (PRs).Materials and MethodsThis retrospective study consisted of 200 mandibular third molars from 200 patients who showed a close relationship between the mandibular canal and impacted third molars on PRs and were referred for a CBCT examination of the position of the mandibular canal. The sample consisted of 124 females and 76 males, with ages ranging from 18 to 47 years (mean, 25.75±6.15 years). PRs were evaluated for interruption of the mandibular canal wall, darkening of the roots, diversion of the mandibular canal, and narrowing of the mandibular canal. Correlations between the PR and CBCT findings were statistically analyzed.ResultsIn total, 146 cases (73%) showed an absence of canal cortication between the mandibular canal and impacted third molar on CBCT images. A statistically significant relationship was found between CBCT and PR findings (P<0.05). The absence of canal cortication on CBCT images was most frequently accompanied by the PR sign of diversion of the mandibular canal (96%) and least frequently by interruption of the mandibular canal wall (65%).ConclusionCBCT examinations are highly recommended when diversion of the mandibular canal is observed on PR images to reduce the risk of mandibular nerve injury, and this sign appears to be more relevant than other PR signs.

Orthopantomography and Cone-Beam Computed Tomography for the Relation of Inferior Alveolar Nerve to the Impacted Mandibular Third Molars.

Context:Relation of inferior alveolar nerve to the impacted mandibular third molars (IMTMs).Aims:The aim of this study was to assess the reliability of seven specific radiographic signs of mandibular third molar root that are observed on orthopantomography (OPG) and to predict the proximity and the absence of corticalization between the mandibular canal and IMTM root on cone-beam computed tomography (CBCT) images.Settings and Design:The present study was conducted in the Department of Oral and Maxillofacial Surgery, Raja Rajeswari Dental College and Hospital.Subjects and Methods:Data set of 30 panoramic images was retrieved between the year of 2015 and 2016 indicated for extraction of lower third molars. The sample consisted of 30 individuals, who underwent preoperative radiographic evaluation before the extraction of impacted mandibular third molars (IMTM). Patients aged above 18 years with any of the seven specific signs observed on the panoramic radiograph which includes darkening, deflection, narrowing of roots, bifid root apex, diversion, narrowing of canal and interruption in the white line of the canal were included in the study. If any of the above mentioned seven specific sign were present, the patient was subjected to CBCT. On the CBCT images, the canal was traced in three planes. The acquired images were assessed for the presence or absence of corticalization.Statistical Analysis Used:Descriptive and inferential statistical analyses were used. Proportions were compared using the Chi-square test and Student's t-test.Results:Among the 4 subjects, diagnosed with an absence of corticalization, patients with isolated darkening of root P = 0.001 and patients with isolated interruption in white line P = 0.69. Patients with darkening of root in association with interruption in white lines on OPG showed the absence of corticalization on CBCT findings P = 0.001, respectively.Conclusions:This study showed the poor reliability of radiographic signs seen on OPG on predicting the proximity of third mandibular root with mandibular canal related to CBCT finding. Four were diagnosed with the absence of corticalization in CBCT findings.

Impact of onlay fusion and cone beam computed tomography on radiation exposure and technical assessment of fenestrated-branched endovascular aortic repair

ObjectiveThe objective of this study was to analyze the impact of advanced imaging applications and cone beam computed tomography (CBCT) on radiation exposure of the patient and operator and detection of technical problems during fenestrated-branched endovascular aortic repair (F-BEVAR) for treatment of pararenal aneurysms and thoracoabdominal aortic aneurysms (TAAAs). MethodsWe reviewed the clinical data of 386 consecutives patients (289 male; mean age, 75 ± 8 years) treated by F-BEVAR for 196 pararenal aneurysms and 190 TAAAs (mean, 3.4 ± 0.9 targeted vessels/patient) between 2007 and 2017. Radiation exposure (cumulative air kerma) was analyzed in three fixed imaging systems used between 2007 and 2011 (system 1), 2012 and 2016 (system 2), and 2016 and 2017 (system 3). Onlay fusion and CBCT were available with systems 2 and 3, whereas digital zoom with fusion overlay was used with system 3. Operator effective dose was measured per month using a radiation dosimeter badge. Computed tomography angiography and CBCT were analyzed for findings requiring immediate revision or secondary interventions. End points were patient radiation exposure; operator effective dose; procedure technical success; and 30-day rates of mortality, major adverse events, and secondary interventions. ResultsF-BEVAR was performed using system 1 in 98 patients, system 2 in 198 patients, and system 3 in 90 patients. Use of onlay fusion/CBCT was 0% with system 1, 42% with system 2, and 98% with system 3. Procedures performed with onlay fusion/CBCT had significantly (P < .05) higher technical success (99.4% vs 98.8%) and lower contrast material volume (155 ± 58 mL vs 172 ± 80 mL), fluoroscopy time (83 ± 34 minutes vs 94 ± 49 minutes), and cumulative air kerma (2561 ± 1920 mGy vs 3767 ± 2307 mGy). Despite higher case volume and increasing complexity during the experience, operator effective dose decreased to 9 ± 4 × 10−2 mSv/case with system 3 compared with 26 ± 3 × 10−2 mSv/case with system 1 and 20 ± 2 × 10−2 mSv/case with system 2 (P = .001). Among 219 patients who had no CBCT, 18 (8%) had computed tomography angiography findings that prompted secondary interventions before dismissal. Conversely, among 167 patients who had CBCT, 14 patients (8%) had intraoperative CBCT findings requiring immediate revision, with no additional secondary interventions. Patients treated with onlay fusion/CBCT had significantly (P < .05) lower mortality (4% vs 1%), major adverse events (43% vs 19%), and secondary interventions (10% vs 4%) at 30 days. ConclusionsRadiation exposure and operator effective dose significantly decreased with evolution of F-BEVAR experience and use of advanced imaging applications such as onlay fusion and CBCT. CBCT allowed immediate assessment and identified intraoperative technical problems, leading to immediate revision and avoiding early secondary interventions.