Imaging of Fibro-osseous Lesions and Other Bone Conditions of the Jaws.

This review directs the focus on the imaging features of various fibro-osseous lesions and other bone lesions that can be of similar presentation. Broad diagnosis of "fibrous osseous lesion" may culminate in improper treatment and management. Radiographic discriminating factors between these entities are highlighted and summarized to improve the diagnostic process when encountering these lesions.

Odontogenic Factors Associated with Maxillary Sinus Schneiderian Membrane Thickness and their Relationship to Chronic Sinonasal Symptoms: An Ambispective Cohort Study.

Odontogenic sinusitis is a common maxillary sinus disease. It develops due to the violation of the Schneiderian membrane due to pathological, iatrogenic, or traumatic causes from dental and dentoalveolar structures. The aim of this cohort study was to investigate local and systemic factors associated with Schneiderian mucosal thickening (MT) in patients referred for evaluation of apical periodontitis (AP) and examine their relationship with chronic sinonasal symptoms. Cone-beam computed tomography (CBCT) scans of 197 patients referred for evaluation of endodontic diseases were reviewed. Mucosal thickening in relation to the affected tooth was measured in the coronal section in millimeters at the maximum area perpendicular to the bone. Based on this measurement, the sinus floor was categorized for MT as present (>1 mm) or absent (<1 mm). The sociodemographic and clinical characteristics of the study participants were assessed and compared according to the presence or absence of MT. Furthermore, the relationship between odontogenic sinusitis and chronic sinonasal symptoms was assessed using a chronic sinusitis survey. Male patients had a higher MT than female patients. The presence of periapical lesions and inadequate endodontic treatment were significantly associated with MT. The multivariate logistic regression model showed that the presence of AP increased the odds of MT by approximately 2.5 times (p = 0.028), and nasal obstruction was significantly higher in patients diagnosed with mucosal thickness at different times of their follow-up period (p = 0.018). MT was 2.5 times more likely in the presence of apical periodontitis, and nasal obstruction was the most significant factor associated with the presence of MT.

Virtual reality simulation of panoramic radiographic anatomy for dental students.

PURPOSE: This work aimed to utilize virtual reality (VR) in dental radiographic anatomical interpretation in junior dental students and test if it can enhance student learning, engagement, and performance. METHODS: VR software for panoramic anatomy was developed. Sixty-nine first-year dental students were divided into a control group (lecture-based) and an experimental group (VR) to learn panoramic radiographic anatomy. Both groups were then tested on knowledge via a 20-question quiz. Student feedback on VR experience was collected via an online survey. RESULTS: There was a statistically significant difference between lecture-based and VR students in the correct identification of anatomical landmarks. Lecture-based students scored higher in identifying the ear lobe, hyoid bone, condylar neck, and external oblique ridge, whereas VR students scored higher in identifying zygoma (Chi-squared test, p < 0.005). The VR group reported high evaluation on all perception items of the online feedback survey on their experience (Student t-test, p < 0.005). CONCLUSIONS: Lecture-based students generally showed better performance in panoramic radiographic anatomy. Several structures were not correctly identified in both groups of novice students. The positive feedback of VR experience encourages future implementation in education to augment conventional methods of radiographic anatomy in dentistry with considerations to repeated exposures throughout undergraduate dental education.

Cone Beam CT Features and Oral Radiologist's Decision-making of Arrested Pneumatization of the Sphenoid Sinus.

OBJECTIVES: To assess the demographic and radiographic features of arrested pneumatization of the sphenoid sinus (APS) and their influence on the confidence of oral and maxillofacial radiologists (OMFRs) in diagnosing APS. METHODS: Reports of cone beam computed tomography (CBCT) APS were retrieved, and the demographic and radiographic features were retrospectively analyzed. Five OMFRs assessed the CBCT images and their confidence in diagnosing APS. The OMFRs' experience (years), expertise (skull-base CBCT cases/month) and diagnostic confidence level were analyzed for agreement and associations with demographic or radiographic features. RESULTS: Of 29 APS cases, 17 (58.6%) were females, and the mean age was 29.9±19 years. Twenty cases (69.0%) presented unilaterally, and 27 (93.1%) involved the sphenoid body. The most common accessory site was the pterygoid process (19, 65.5%). The vidian canal and foramen rotundum were involved in 27 (93.1%) and 17 (58.6%) cases, respectively. Most cases (28, 96.6%) were well-defined, corticated, and showed mixed attenuation. APS diagnostic confidence was higher among the expert OMFRs (72.4%-82.8% vs. 58.6%-62.1%). CONCLUSION: Radiographic features differentiating APS from skull-base tumors were shown on CBCT. The confidence of OMFRs with similar experience in years depended on their frequency of examining CBCT cases involving the skull base.

Clinical and radiographic features of facial cosmetic materials: A systematic review.

Purpose: The aim of this study was to systematically screen the literature for studies reporting cosmetic material in the oral and maxillofacial complex to shed light on the types of cosmetic materials, their radiographic appearance, and possible complications. Materials and Methods: Five electronic databases were reviewed for eligible studies. The general search terms were "cosmetic," "filler," "face," and "radiograph." Demographics, material types, clinical and radiographic presentation, and complications were recorded. Results: Thirty-one studies with 53 cases met the inclusion criteria. The mean age was 52.6±15.4 years with a 4 : 3 female-to-male ratio. The most common material was calcium hydroxyapatite (CaHa) (n=14, 26.4%), found incidentally. The materials were generally located within the upper cheek and zygoma (n=35, 66.0%), radiographically well-defined (n=44, 83%), and had no effects on the surrounding structures (n=27, 50.9%). The internal structure was radiopaque (calcification, hyperdensity) for gold wires, CaHa, bone implants, and secondary calcification or ossification. Outdated cosmetic materials or non-conservative techniques were infiltrative, had effects on the surrounding structures, and presented with clinical signs, symptoms, or complications. Conclusion: Conventional radiography, cone-beam computed tomography, and multi-detector computed tomography are useful to differentiate several cosmetic materials. Their magnetic resonance imaging appearance was highly variable. The infrequent inclusion of cosmetic materials in the differential diagnosis implies that medical and dental specialists may be unfamiliar with the radiographic appearance of these materials in the face.

Radiographic Features of Facial Cosmetic Material: Report of Two Cases.

Recently, the use of noninvasive facial cosmetic procedures has been widely disseminated. In the face, cosmetic fillers, threads, and implants are used to reduce or delay the effects of aging or adjust facial defects caused by trauma or disease. The dentist or dental specialist may encounter these materials in the radiographic images of their patients. There are few reports in the dental literature describing the radiographic appearance of some materials along with the diseases they mimic. As the procedures and materials advance and evolve, dentists and dental specialists must be aware of their radiographic appearance to avoid errors in diagnosis. This is a report of two cases that include panoramic radiography and CBCT scan. Among these cases, there is an unusual appearance of a cosmetic filler due to a subperiosteal injection method. Moreover, it will discuss common types of cosmetic materials used in the face and their imaginological appearance. This is the key to dentists and dental specialists due to increasing use of facial cosmetic materials and a parallel increase in the use of cone beam CT and chances to encounter such findings.

Prevalence of maxillary sinus hypoplasia and association with variations in the sinonasal complex: a cone beam CT study.

OBJECTIVE: Understanding of maxillary sinus hypoplasia (MSH) and associated sinonasal variants is paramount to the diagnostic and therapeutic success of maxillary sinus and maxillary dental implant surgery. The purpose of this work was to explore the prevalence of MSH, frequency of mucosal thickening, and anatomical variations in the sinonasal complex. METHODS: Retrospective case-control design based on cone beam CT images of dental patients with MSH and matched for age and gender. MSH type and sinonasal variables were recorded. RESULTS: One thousand three hundred seventy cone beam CT scans were analyzed for MSH. MSH prevalence was 6% (n=82), matched with 82 controls= 100 females and 64 males, mean age 37.1±14.1 years. Most MSH were type I, 69.5%, 80.5% unilateral, 65.9% associated with no or mild mucosal thickening. Associated sinonasal anatomical variations were <27% except for deviated/hyperplastic (DH) meatus, 48.8%. Within the MSH group, significant associations were presented between MSH type, mucosal thickening, and DH nasal meatus. MSH group vs controls showed a significant difference in mucosal thickening (OR 5.2, 95% CI 2.0-17.3) and DH meatus (OR 1.6, 95% CI 1.4-2.1). CONCLUSIONS: A hypoplastic maxillary sinus with abnormal or absent uncinate process is associated with advanced mucosal thickening and may present with altered anatomy of the lateral wall of the nasal cavity causing its approximation to the orbital floor. CLINICAL RELEVANCE: Pre-surgical knowledge of altered anatomy in the sinonasal complex is crucial in dental implant or sinus surgery.

Systematic Review of Clinical and Radiographic Signs of Pediatric Pleomorphic Adenoma of Minor Salivary Glands.

AIM AND OBJECTIVE: To examine the clinical signs, radiographical features, and demographics of pediatric pleomorphic adenoma (PA) in the minor salivary glands. MATERIALS AND METHODS: Several databases were searched for relevant studies. The included studies were assessed for methodological quality. Demographic, clinical, and radiographic data were collected. RESULTS: Sixteen of 3,121 articles met the inclusion criteria (17 lesions). The mean age was 9.7 ± 3.9 years and majority were females n = 10 (59%). It is commonly presented as asymptomatic swelling n = 16 (94.1%), in the hard palate 13 (76.5%). Radiographically, most were well-defined n = 15 (93.7%) and 8 (47%) caused erosion or displacement of surrounding tissues. CONCLUSION: The small size and asymptomatic nature of pediatric PA can render these lesions undiagnosed. On rare occurrences, PA can show calcifications, MRI, or CT enhancement. MRI is the best imaging modality to depict soft tissue content but not subtle erosion of adjacent bony structures. CLINICAL SIGNIFICANCE: The dentist can be the first to detect PA in the mouth of a child. Augmenting clinical examination with radiographic examination is paramount to ensure adequate diagnosis of PA, examine effects on surrounding bone, and maintain close follow-up as watchful waiting is not safe in this population.

A systematic review of the clinical and radiographic features of hybrid central giant cell granuloma lesions of the jaws.

OBJECTIVE: Central giant cell granuloma (CGCG) can coexist with other benign lesions of the jaw. These hybrid lesions are diagnostically challenging to both oral pathologists and radiologists. This work systematically reviews the clinical and radiographic features of hybrid-CGCG lesions in the jaws. MATERIALS AND METHODS: Three reviewers conducted an electronic search of five databases for histologically diagnosed hybrid-CGCG lesions in human jaws. RESULTS: Thirty-four of 1224 articles met the inclusion criteria. Of 39 hybrid-CGCG lesions, 14 (35.9%) were central odontogenic fibroma, 11 (28.2%) were central ossifying fibroma, seven (17.9%) were fibrous dysplasia, and seven (17.9%) were other bone conditions. There were 22 females and 17 males with a mean age of 30.5 ± 19.9 years. 89.5% of hybrid-CGCG lesions were well defined, 57.9% were non-corticated, 60.5% were radiolucent, and 66.7% were in the posterior mandible. Most hybrid lesions affected the cortical plates by thinning, expansion, or perforation (93.1%), displaced, or resorbed teeth (60%). CONCLUSION: The radiographic features of hybrid-CGCG lesions vary according to the concurrent bony lesion. Hybrid-CGCG lesions altered the radiographic appearance with the following entities: fibrous dysplasia, melorheostosis, and Paget's disease. Optimal imaging modalities are crucial to detail radiographic features and direct representative biopsy of suspicious sites that may host a CGCG hybridisation.

Incidental Cone Beam CT Finding of Juvenile Pleomorphic Adenoma.

Pleomorphic adenoma is a benign mixed tumor composed of epithelial and myoepithelial cells, less commonly occurring in minor salivary glands or in children. A case of juvenile pleomorphic adenoma missed clinically and incidentally found in cone beam CT images is described. Clinical, radiographic, and histologic images are presented.

Pediatric sleep-disordered breathing in the orthodontic population: Prevalence of positive risk and associations.

INTRODUCTION: Pediatric sleep-disordered breathing (SDB) describes a spectrum of disease ranging from snoring to upper airway resistance syndrome and obstructive sleep apnea (OSA). Anatomical features assessed during orthodontic exams are often associated with symptoms of SDB in children. Hence, we need to determine the prevalence of positive risk for SDB in the pediatric orthodontic population compared with a general pediatric population and understand comorbidities associated with SDB risk among orthodontic patients. METHODS: Responses from Pediatric Sleep Questionnaires were collected from 390 patients between the ages of 5 and 16 years, seeking orthodontic treatment. Prevalence of overall SDB risk, habitual snoring, and sleepiness were determined in the orthodontic population and compared with those previously reported by identical methods in the general pediatric population. Additional health history information was used to assess comorbidities associated with SDB risk in 130 of the patients. RESULTS: At 10.8%, the prevalence of positive SDB risk was found to be significantly higher in the general pediatric orthodontic population than in a healthy pediatric population (5%). The prevalence of snoring and sleepiness in the orthodontic population was 13.3% and 17.9%, respectively. Among the comorbidities, nocturnal enuresis (13.6%), overweight (18.2%), and attention deficit hyperactivity disorder (31.8%) had a higher prevalence in orthodontic patients with higher SDB risk (P < 0.05). CONCLUSIONS: There is a higher pediatric SDB risk prevalence in the orthodontic population compared with a healthy pediatric population. Orthodontic practitioners should make SDB screening a routine part of their clinical practice.

Correlation and reliability of cone-beam computed tomography nasopharyngeal volumetric and area measurements as determined by commercial software against nasopharyngoscopy-supported diagnosis of adenoid hypertrophy.

INTRODUCTION: The aim of this study was to evaluate the diagnostic correlation and reliability of Dolphin Imaging fully automated segmentation (Dolphin Imaging and Management Solutions, Chatsworth, Calif) for assessing adenoid hypertrophy. This was investigated through 3 modes: (1) intraobserver and interobserver agreement of repeated airway auto-segmentation procedures, (2) correlation between auto-segmentation measures of volume and minimal cross-sectional airway against nasopharyngoscopy, and (3) optimum diagnostic cutoff thresholds for volume and minimal cross-sectional airway identified and tested with sensitivity and specificity analyses. METHODS: Cone-beam computed tomography scans of 38 patients with suspected upper airway obstruction were analyzed. Two calibrated evaluators applied a previously validated method to quantify nasopharyngeal minimal cross-sectional airway and volume using Dolphin Imaging. Assessments were compared against grades of obstruction provided by otolaryngologists' diagnoses. RESULTS: The reliability between the 2 assessments by the same evaluator on the Dolphin automatic segmentation function for volume (ICC, 0.97; 95% CI, 0.95, 0.98) and minimal cross-sectional airway (ICC, 0.84; 95% CI, 0.69, 0.91) was excellent. The interoperator reliability for volume was also excellent (ICC, 0.97; 95% CI, 0.95, 0.98), but only good (ICC, 0.701; 95% CI, 0.44, 0.85) for minimal cross-sectional airway. In contrast, the Spearman rank correlation test demonstrated weak associations between the values of the automatic measurements for both volume (4.9%; ρ = -0.22) and minimal cross-sectional airway (3.7%; ρ = 0.19). Assessments of accuracy via Receiver Operating characteristic analysis, sensitivity, specificity, negative predictive values, positive predictive values, and likelihood ratios demonstrated the poor clinical applicability of volume and minimal cross-sectional airway numbers provided by Dolphin Imaging. CONCLUSIONS: The evaluators were reliable at manipulating the selected software, achieving consistent volume and minimal cross-sectional airway measurements, However, Dolphin Imaging volumetric and minimal cross-sectional airway measurements did not correlate well with the nasopharyngoscopy-supported reference standard for adenoid hypertrophy assessment. Under these study conditions, volume and minimal cross-sectional airway used to assess localized adenoid hypertrophy with cone-beam computed tomography imaging based on automated measurements may not yield high-quality clinically relevant information about upper airway constriction related to adenoid hypertrophy.

Predictors of failure of DISE-directed adenotonsillectomy in children with sleep disordered breathing.

BACKGROUND: Adenotonsillectomy (AT) is the most commonly performed procedure for sleep disordered breathing (SDB) in pediatrics. However, 20-40% of patients will have persistent signs and symptoms of SDB after AT. Drug-induced sleep endoscopy (DISE) has the potential to individualize surgical treatments and avoid unnecessary or unsuccessful surgeries. The objective of this study was to determine the predictors of failure of DISE-directed adenoidectomy and/or tonsillectomy in otherwise healthy children with SDB. METHODS: We retrospectively reviewed a prospective database of children who presented with SDB. All patients underwent preoperative pulse oximetry (PO), followed by DISE with T ± A, The variables documented included demographics, ethnicity, co-morbidities, family history, McGill Oximetry Score (MOS) on PO, as well as findings of collapse and or obstruction on DISE and symptom resolution based on modified Pediatric Sleep Questionnaire (PSQ). The primary outcome was the independent predictors of treatment failure based on multivariate binary logistic regression. RESULTS: Three hundred eighty-two patients satisfied the inclusion criteria. Based on post-operative modified PSQ, SDB resolved in 259 patients (68%), whereas 123 (32%) had persistent symptoms. On bivariate analysis, neuropsychiatric diagnosis (r = 0.286, p = 0.042), history of sleepwalking or enuresis (r = 0.103, p = 0.044), MOS (r = 0.123, p = 0.033), presence of DNS (r = 0.107, p = 0.036), and presence of laryngomalacia (r = 0.122, p = 0.017) all positively correlated with treatment failure. Small tonsil size on DISE correlated with treatment failure (r = -0.180, p < 0.001). Multivariate analysis identified age greater than 7 years (OR = 1.799, [95% CI 1.040-3.139], p = 0.039), obesity (OR = 2.032, [95% CI 1.043-3.997], p = 0.040), chronic rhinitis (OR = 1.334, [95% CI 1.047-1.716], p = 0.025), deviated nasal septum (OR = 1.745, [95% CI 1.062-2.898], p = 0.031) and tonsil size (OR = 0.575, [95% CI 0.429-0.772], p < 0.01) as independent predictors of treatment failure. CONCLUSIONS: Obese, asthmatic, and children older than seven years are at increased risk of treatment failure after DISE-directed AT. Several DISE findings can independently predict AT failure, including tonsil size, degree of chronic rhinitis, and the presence of a deviated nasal septum, and can be addressed at a second stage. Further research is needed into the role of DISE in surgically naïve patients with SDB, and to compare DISE-directed surgery with the current standard of care.

Cone beam computed tomography incidental findings of the cervical spine and clivus: retrospective analysis and review of the literature.

OBJECTIVE: The aim of this study was to analyze and describe incidental findings in the cervical spine (C-spine) and the clivus encountered in cone beam computed tomography (CBCT) imaging. The wide range of possible anatomic variants and pathoses is discussed in the context of the medical and dental literature to clarify their radiographic appearance and clinical implications as a guide for the oral and maxillofacial radiologist. STUDY DESIGN: A retrospective analysis of radiographic reports was conducted based on CBCT images from 2 oral and maxillofacial imaging centers. Reports documenting incidental findings in the C-spine or the clivus were selected. Data on patient age and sex were collected, and each incidental finding was categorized as degenerative, congenital, or developmental/pathologic. Each finding is discussed with clinical importance and is pictorially presented. RESULTS: From a total of 7689 CBCT reports, there were 732 incidental findings (9.5%) in the C-spine or the clivus. Most findings were in the C-spine (92.3%), were degenerative in nature (78.7%), and occurred in females in their sixth decade. Logistic regression analysis showed that the odds of presenting with a degenerative incidental finding in the C-spine or the clivus did not differ based on sex but were 5.5 times (95% confidence interval, 3.77-8.04) higher if the patient was aged 50 years or older. CONCLUSIONS: This review is the largest and the first to characterize incidental findings in the C-spine and the clivus. Such findings were reported in 9.5% of radiographic reports. Several presented as uncommon congenital variants that are not usually spotlighted during oral and maxillofacial radiology training.

Using cone beam CT to assess the upper airway after surgery in children with sleep disordered breathing symptoms and maxillary-mandibular disproportions: a clinical pilot.

BACKGROUND: The surgical excision of anatomic obstructions such as adenoids, palatine or lingual tonsils are commonly performed in children with sleep disordered breathing (SDB). Imaging studies measuring airway changes post-surgery in the SDB pediatric population are scarce, rarely addresses the nasal cavity, and are based on global measures (e.g. volume) that do not represent the complexity of the upper airway anatomy. The purpose of this pilot is to test the feasibility in using cone beam CT (CBCT) to analyze the nasal and pharyngeal airway space post-surgery using meaningful methods of analyses, and correlating imaging findings with clinical outcomes in children with SDB symptoms and maxillary-mandibular disproportion. METHODS: Twelve non-syndromic children with SDB symptoms and jaw disproportions were evaluated by interdisciplinary airway team before and after upper airway surgery. CBCT and OSA-18 quality of life questionnaire pre and post-operatively were completed. Conventional and new airway variables were measured based on 3D models of the upper airways and correlated with OSA-18. Conventional measures include volume, surface area, and cross-sectional area. New airway measures include constriction and patency; point-based analyses. RESULTS: Eight females and four males were 8.8 ± 2 years with mean BMI of 18.7 ± 3. OSA-18 improved, median (lower quartile-upper quartile) from 64.2 (54.7-79.5) to 37.6 (28.7-43) postoperatively, p < 0.001. The median of all airway measures improved however with very wide range. Subjects with the smallest amounts of constriction relief and/or gain in airway patency presented with least improvement in OSA-18. New airway measures show strong correlation with changes in OSA-18 (ρ = 0.44 to 0.71) whereas conventional measures showed very weak correlation (ρ = -0.04 to 0.37). CONCLUSIONS: Using point-based analyses, new airway measures better explained changes in clinical symptoms compared to conventional measures. Airway patency gained by at least 150% and constriction relief by at least 15% showed marked improvement in OSA-18 by 40-55%, after surgery in the tested cohort.

Does drug-induced sleep endoscopy change the surgical decision in surgically naïve non-syndromic children with snoring/sleep disordered breathing from the standard adenotonsillectomy? A retrospective cohort study.

BACKGROUND: Adenotonsillectomy is the most commonly performed operation for pediatric snoring/sleep disordered breathing (S/SDB). However, 20-40% of patients will fail to improve. Drug-induced sleep endoscopy (DISE) may provide a more individualized surgical plan and limit unsuccessful surgeries. The aim of this study was to assess the impact of DISE on surgical decision-making in surgically naïve children with S/SDB. METHODS: A retrospective observational cohort study was undertaken at the Stollery Children's Hospital. Patients 3-17 years of age who underwent DISE-directed surgery for S/SDB between January 2009 and December 2015 were eligible. We excluded other indications for tonsillectomy and syndromic children. The primary outcome was the level of agreement between a DISE-based surgical decision and the reference standard based on the American Academy of Pediatrics (AAP) guidelines via un-weighted Cohen's kappa. Secondary outcomes included the frequency and type of alternate surgical targets identified by DISE. The agreement on tonsil size between in-office physical assessment and DISE was also calculated. The effectiveness of DISE-directed surgery on postoperative S/SDB was not investigated. RESULTS: Five hundred fifty-eight patients were included. DISE changed the surgical plan in 35% of patients. Agreement between DISE-based and AAP clinical practice guidelines-based management was low (κ = 0.354 +/- 0.021 [95% CI 0.312-0.395]). An alternate diagnosis or surgical target was identified by DISE in 54% of patients. There was moderate agreement on tonsil size (κ = 0.44 [0.33-0.55]) between DISE and in-office clinical assessment. CONCLUSIONS: This is a first phase diagnostic study, which demonstrates that DISE affects decision-making in surgically naïve children with S/SDB in up to 35% of patients. It has utility in individualizing first stage surgical treatments as well as identifying alternate targets for further surgical or medical therapy, while potentially limiting unsuccessful surgeries. Further studies to examine the effect of DISE on surgical outcomes are required.

Usefulness of MRI-CBCT image registration in the evaluation of temporomandibular joint internal derangement by novice examiners.

OBJECTIVE: To assess whether novice examiners can more reliably determine temporomandibular joint (TMJ) disk derangements with the use of fused images of magnetic resonance imaging and cone beam computed tomography (MRI-CBCT) compared with MRI images alone. STUDY DESIGN: Thirty dental students with minimal exposure to TMJ imaging received a 30-minute calibration session in which TMJ diagnostic imaging and the normal anatomy of the TMJ internal derangement were explained. The students evaluated the disk positions of 16 TMJs in two sets of images (MRI images alone and MRI-CBCT images) randomly and independently. The disk positions evaluated by two experienced radiologists were used for comparison. RESULTS: The internal consistency among all students improved from an unacceptable consistency (α = 0.40) with MRI images alone to a good consistency (α = 0.84) with MRI-CBCT images. The agreement in evaluation between the students and the radiologists improved from a poor agreement with MRI images alone (k mean = 0.07 ± 0.12) to a moderate agreement with MRI-CBCT images (k mean = 0.55 ± 0.25). This improvement in the agreement was significant (P < .001). CONCLUSIONS: The use of fused MRI and CBCT images to visualize the TMJ in a single display significantly improved the examiners' reliability and accuracy of assessment of disk positions. The improvement of novice readers in assessing the disk positions highlights the potential use of MRI-CBCT image fusion as an educational tool.

Accuracy and reliability of orthodontists using cone-beam computerized tomography for assessment of adenoid hypertrophy.

INTRODUCTION: Our objectives were to evaluate the reliability of agreement between orthodontists, with various degrees of cone-beam computed tomography (CBCT) imaging manipulation comfort, in classifying adenoid hypertrophy through CBCT generated images and also to determine how accurate orthodontists are compared with the gold standard diagnosis, nasopharyngoscopy. METHODS: This was a cross-sectional study in which a randomized list of board-certified orthodontists evaluated different degrees of adenoid hypertrophy of a stratified sampling of 10 scans. The available pool of CBCT images was from a multidisciplinary airway clinic in which children and adolescents had a CBCT scan and a nasopharyngoscopy (reference standard) by an otolaryngologist (head and neck surgeon) on the same day. The participating orthodontists used the same viewer software and computer, and had access to a previously published visual guideline for evaluating adenoid size. RESULTS: Fourteen orthodontists evaluated 10 CBCT reconstructions. Interoperator reliability was excellent (intraclass correlation coefficient [ICC], 0.941; 95% confidence interval, 0.882-0.984). However, the orthodontists' evaluations against the reference standard demonstrated poor accuracy, (ICC mean, 0.39; ICC range, 0.0-0.74). Dichotomous data representing healthy and unhealthy patients were analyzed individually, and the orthodontists' evaluations and the nasopharyngoscopy results (accuracy) showed, on average, poor kappa values (mean, 0.44; range, 0.20-0.80). CONCLUSIONS: Different levels of CBCT expertise impacted the assessment accuracy. The participating orthodontists showed excellent consistency among themselves; however, poor agreement between their CBCT assessments compared with nasopharyngoscopy demonstrated that this sample of clinical orthodontists had poor diagnostic accuracy. Together, these findings suggest that orthodontists may make consistent and systematic errors in this type of evaluations.

MRI alone versus MRI-CBCT registered images to evaluate temporomandibular joint internal derangement.

OBJECTIVE: To evaluate the effect of magnetic resonance imaging-cone beam computed tomography (MRI-CBCT) image registration on inter- and intraexaminer consistency when evaluating temporomandibular joint (TMJ) internal derangement compared to MRI alone. METHODS: MRI and CBCT images of 25 patients (50 TMJs) were obtained and coregistered using mutual-information rigid image registration via Mirada XD software. Two experienced radiologists independently and blindly evaluated two types of images (MRI alone and MRI-CBCT registered images) at two different times (T1 and T2) for TMJ internal derangement, based on sagittal and coronal articular disc position in relation to the head of the condyle and the posterior slope of the articular eminence. RESULTS: The intraexaminer consistency with MRI alone (examiner 1 = 0.85 [0.74-0.92]; examiner 2 = 0.91 [0.84-0.95]) was lower than for the MRI-CBCT registered images (examiner 1 = 0.95 [0.91-0.97]; examiner 2 = 0.97 [0.96-0.99]). The interexaminer consistency of evaluating internal derangement with MRI alone (0.52 [0.18-0.73] at T1; 0.71 [0.45-0.84] at T2) was lower than for the MRI-CBCT registered images (0.97 [0.95-0.98] at T1; 0.98 [0.96-0.99] at T2). When disc position classification was dichotomized to normal versus anteriorly displaced, intraexaminer agreement for the two examiners was 0.52 and 0.63 for MRI alone, but was 0.91 and 0.92 for MRI-CBCT registered images. Interexaminer agreement for MRI alone was 0.29 at T1 and 0.42 at T2, but was 0.96 at both examination times for MRI-CBCT registered images. CONCLUSION: The MRI-CBCT registered images improved intra- and interexaminer consistency in the evaluation of internal derangement of TMJ.

New algorithm for semiautomatic segmentation of nasal cavity and pharyngeal airway in comparison with manual segmentation using cone-beam computed tomography.

INTRODUCTION: Our objectives were to assess reliability, validity, and time efficiency of semiautomatic segmentation using Segura software of the nasal and pharyngeal airways, against manual segmentation with point-based analysis with color mapping. METHODS: Pharyngeal and nasal airways from 10 cone-beam computed tomography image sets were segmented manually and semiautomatically using Segura (University of Alberta, Edmonton, Alberta, Canada). To test intraexaminer and interexaminer reliabilities, semiautomatic segmentation was repeated 3 times by 1 examiner and then by 3 examiners. In addition to volume and surface area, point-based analysis was completed to assess the reconstructed 3-dimensional models from Segura against manual segmentation. The times of both methods of segmentation were also recorded to assess time efficiency. RESULTS: The reliability and validity of Segura were excellent (intraclass correlation coefficient, >0.9 for volume and surface area). Part analysis showed small differences between the Segura and manually segmented 3-dimensional models (greatest difference did not exceed 4.3 mm). Time of segmentation using Segura was significantly shorter than that for manual segmentation, 49 ± 11.0 vs 109 ± 9.4 minutes (P <0.001). CONCLUSIONS: Semiautomatic segmentation of the pharyngeal and nasal airways using Segura was found to be reliable, valid, and time efficient. Part analysis with color mapping was the key to explaining differences in upper airway volume and provides meaningful and clinically relevant analysis of 3-dimensional changes.