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.

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.

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.

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.

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.

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.

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.

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.

Accuracy and reliability of oral maxillofacial radiologists when evaluating cone-beam computed tomography imaging for adenoid hypertrophy screening: a comparison with nasopharyngoscopy.

OBJECTIVE: To determine how accurate and reliable oral maxillofacial radiologists (OMFRs) are in screening for adenoid hypertrophy when using cone-beam computed tomography (CBCT) imaging compared with nasopharyngoscopy (NP). STUDY DESIGN: CBCT scans of 10 patients with distinct levels of adenoid hypertrophy were randomly selected. Fourteen board-certified OMFRs classified the levels of hypertrophy. The intraclass correlation coefficient (ICC) was used to assess accuracy by comparing their diagnosis against an NP diagnosis, which is the reference standard. OMFRs' interreliability was assessed. Kappa statistics were used to analyze dichotomous data from healthy and unhealthy patients. RESULTS: Overall, the reliability among OMFRs was good (ICC = 0.79 with confidence interval [CI] 0.63-0.93). The "statistical mode" was very good (ICC = 0.81; CI 0.43-0.94). The accuracy of OMFRs against NP was good (ICCmean = 0.69; CI 0.43-0.94). On average, the Kappa statistics (Kmean = 0.77; CI 0.62-0.92) demonstrated a good agreement between OMFRs and NP diagnoses. The individualized results from each evaluator were presented and investigated according to their performance. CONCLUSIONS: Compared with the reference standard, the accuracy of OMFRs to classify adenoid hypertrophy on a four-level scale was moderate to strong and improved when adenoid hypertrophy was classified as healthy or unhealthy. The reliability of the OMFRs was greater than 80%, assuring their consistency and reliability on screening adenoids hypertrophy via CBCT.

MRI and CBCT image registration of temporomandibular joint: a systematic review.

PURPOSE: The purpose of the present review is to systematically and critically analyze the available literature regarding the importance, applicability, and practicality of (MRI), computerized tomography (CT) or cone-beam CT (CBCT) image registration for TMJ anatomy and assessment. DATA SOURCES: A systematic search of 4 databases; MEDLINE, EMBASE, EBM reviews and Scopus, was conducted by 2 reviewers. An additional manual search of the bibliography was performed. INCLUSION CRITERIA: All articles discussing the magnetic resonance imaging MRI and CT or CBCT image registration for temporomandibular joint (TMJ) visualization or assessment were included. RESULTS AND INCLUDED ARTICLES' CHARACTERISTICS: Only 3 articles satisfied the inclusion criteria. All included articles were published within the last 7 years. Two articles described MRI to CT multimodality image registration as a complementary tool to visualize TMJ. Both articles used images of one patient only to introduce the complementary concept of MRI-CT fused image. One article assessed the reliability of using MRI-CBCT registration to evaluate the TMJ disc position and osseous pathology for 10 temporomandibular disorder (TMD) patients. CONCLUSION: There are very limited studies of MRI-CT/CBCT registration to reach a conclusion regarding its accuracy or clinical use in the temporomandibular joints.

Accuracy of magnetic resonance imaging-cone beam computed tomography rigid registration of the head: an in-vitro study.

OBJECTIVE: To evaluate the performance of cross-modality image registration procedure between magnetic resonance imaging (MRI) and cone beam computed tomography (CBCT). METHODS: In vitro diagnostic MRI and CBCT images of 5 cadaver swine heads were obtained prospectively. Five radiopaque fiducial markers were attached to each cadaver skull by using resin screws. Automatic MRI-CBCT rigid registrations were performed. The specimens were then scanned using a 3-dimensional (3-D) laser scanner. The 3-D coordinate points for the centroid of the attached fiducial markers from laser scan were identified and considered ground truth. The distances between marker centroids were measured with MRI, CBCT, and MRI-CBCT. Accuracy was calculated by using repeated measures analysis of variance and mean difference values. The registration method was repeated 10 times for each specimen in MRI to measure the average error. RESULTS: There was no significant difference (P > .05) in mean distances of the markers between all images and the ground truth. The distances' mean difference between MRI, CBCT, and MRI-CBCT and the ground truth were 0.2 ± 1.1 mm, 0.3 ± 1.0 mm, 0.2 ± 1.2 mm, respectively. The detected method error ranged between 0.06 mm and 0.1 mm. CONCLUSION: The cross-modality image registration algorithm is accurate for head MRI-CBCT registration.

Cone beam computed tomography registration for 3-D airway analysis based on anatomic landmarks.

OBJECTIVES: Explore craniofacial landmarks reliability to superimpose cone beam computed tomography (CBCT) images and assess impact of plane reorientation on airway parameters. STUDY DESIGN: 10 CBCTs were marked 3 times at baseline, 3 T1, to test landmark reliability. Measurement errors of new coordinate system were tested using 3 T1, and other 10 paired CBCT images, at T1 and T2. Effect on upper airway was assessed using volume, surface area, and point-based analysis. RESULTS: Tips of nasal bone and clivus and foramina spinosa defined the new coordinate system. Plane reorientation didn't affect landmark identification reliability and significantly reduced interlandmark distances from T1-T2. Airway volume changed by 25.76 ± 24.9%, surface area by 13.85 ± 10.8%, and mean part analysis was 0.43 ± 0.3 mm. Strong correlation (R(2) > 65%) was found between airway analysis and large distances in second and third cervical vertebrae. CONCLUSIONS: Coordinate transformation significantly reduced measurement errors in longitudinal CBCT data; however, it is not designed to correct for large neck flexion.

Reliability of anatomic structures as landmarks in three-dimensional cephalometric analysis using CBCT.

OBJECTIVE: To identify anatomic structures in three dimensions and examine their reliability to be used as landmarks in a three-dimensional coordinate cephalometric analysis, using cone-beam computerized tomography (CBCT). MATERIALS AND METHODS: Thirty CBCT images were randomly selected for landmark location. Forty-two anatomic landmarks, which are not included in the traditional cephalometric landmarks, were chosen based on radiographic characteristics that make them pragmatic to mark in the CBCT image slices. The principal investigator marked the full set of landmarks on the software by navigating in the X, Y, and Z axes for every image three times, with each measurement trial being at least 1 week apart. One other investigator also located the landmarks once for each image for reliability purposes. Intraclass correlation coefficients (ICCs) were used to analyze the mean differences in landmark location in all axes. RESULTS: Intra- and interexaminer reliability for x, y, and z coordinates for all landmarks had ICC greater than 0.95 with confidence interval of 0.88-0.99. Mean measurement differences found were <1.4 mm for all landmarks in all three coordinates. Mean measurement error differences obtained in the principal investigator's trials were primarily <0.5 mm. CONCLUSION: The most reliable and reproducible landmarks tested for use in CBCT are mental foramina, infraorbital foramina, inferior hamulus, dens axis, foramina transversarium of atlas, medial and lateral condyles of the mandible, superior clinoid processes, and mid-clinoid.

CBCT assessment of upper airway changes and treatment outcomes of obstructive sleep apnoea: a systematic review.

PURPOSE: The aim of this study was to review studies using cone beam computed tomography (CBCT) to assess dimensional changes in the upper airway after appliance or surgical therapy in subjects with obstructive sleep apnoea and to correlate CBCT findings with treatment outcome. METHOD: Several electronic databases were searched. Studies that met selection criteria were evaluated using a customized evaluation tool. RESULTS: Study parameters were met in seven articles. Fifty adults were assessed using CBCT 1.6-10 months after appliance therapy or maxillary mandibular advancement surgery with or without genial tubercle advancement. Airway parameters measured were linear, cross-sectional (CS) area, volume or airway function. In only two validated surgical case reports, airway volume increased by 6.5-9.7 cm(3) (>80 %) and minimum CS area by 0.1-1.2 cm(2) (21 and 269 %). CONCLUSION: The available published studies show evidence of CBCT measured anatomic airway changes with surgery and dental appliance treatment for OSA. There is insufficient literature pertaining to the use of CBCT to assess treatment outcomes to reach a conclusion. High-quality evidence level studies, with statistically appropriate sample sizes and cross validated clinically, are needed to determine if CBCT airway dimensional changes are suitable for assessment of treatment outcome.

Osseous (cemento-osseous) dysplasia of the jaws: clinical and radiographic analysis.

OBJECTIVES: To explore the demographic characteristics and clinical features among patients with osseous (cemento-osseous) dysplasia (OD/COD) of the jaws and to determine the frequency of particular radiographic characteristics. METHODS: The charts and radiographic reports of 118 patients with OD/COD, obtained from the archives of the University of Toronto discipline of oral and maxillofacial radiology, were reviewed. Demographic and clinical data, radiographic findings and final diagnoses were collected and analyzed to determine typical characteristics. RESULTS: Of the 117 patients for whom age and sex were known, the majority (97 [82.9%]) were female; these female patients had a mean age (± standard deviation) of 44.3 ± 13.4 years. Eighty-three (72.2%) of the 115 patients for whom symptoms were known were clinically asymptomatic. Ninety-three patients (78.8%) had OD/COD at single sites (i.e., periapical OD/COD), and 25 (21.2%) had OD/COD at multiple sites (i.e., florid OD/COD). In addition, 15 (12.7%) of the cases were associated with one or more simple bone cysts, and 13 (11.0%) were associated with osteomyelitis. In most cases, the OD/COD was unilateral, with the lesion being located in the mandible, usually associated only with the posterior teeth. The lesions exhibited well-defined, sclerotic or corticated margins (108 patients [91.5%]) and were surrounded by a radiolucent border. Minimal effects on surrounding structures were observed. As well, 85 (72.0%) of the lesions were in the mixed radiolucent-radiopaque stage, with dense, cementum-like radiopacities. CONCLUSIONS: The majority of cases of OD/COD occurred in women in the fifth decade of life, and most cases were asymptomatic. OD/COD was more likely to present as solitary lesions but also occurred in association with simple bone cysts or osteomyelitis.