Correlation between gonial angle and dynamic tongue collapse in children with snoring/sleep disordered breathing - an exploratory pilot study.

BACKGROUND: Drug induced sleep endoscopy (DISE) is hoped to identify reasons of failure of adenotonsillectomy (AT) in treating pediatric sleep disordered breathing (SDB). Maxillomandibular disproportion has been studied as another association which may explain alternative pathogenesis of SDB. We aimed to explore the relation between the size of the gonial angle and inclination of the epiglottis measured from cone beam CT (CBCT) and tongue base collapse based on DISE in children with SDB. METHOD: A retrospective chart review was conducted at a tertiary pediatric center. Children (6-17 years old) assessed at a multi-disciplinary Upper Airway Clinic, diagnosed with SDB and maxillo-mandibular disproportion (MMD), and who underwent DISE were eligible. Variables obtained from the electronic medical records of the clinic and prospective database included demographics, comorbidities, surgeries performed, investigations, DISE findings and CBCT findings. The gonial angle of subjects with and without tongue base collapse (TBC) on SNP were compared. RESULTS: In total 29 patients (13 male, 8 female) age 6-17 (median= 9) were eligible for the study from January 2009 - July 2016. We included 11 subjects, and 10 comparators. The mean gonial angle of the TBC group was 139.3°± 7.6°, while that of the comparison group was 129.4°±3.5 (mean difference -9.937, 95% CI of -15.454 to - 4.421, P = 0.001, power of test 0.95). Additionally, the mean inclination of the epiglottis had a mild positive correlation (r=0.32, p<0.05) with the gonial angle, in the whole cohort. CONCLUSIONS: This pilot study suggests that TBC may be mediated by a wider gonial angle in children with SDB patients. The posterior tilt of the epiglottis on CBCT may be a surrogate sign of TBC.

Digital Imaging Capability for Caries Detection: A Meta-analysis.

The objective of this study was to identify the diagnostic capability of photostimulable phosphor plates (PSPs) and direct digital sensors (DDSs) in the detection of interproximal caries. Studies were identified that evaluated the diagnostic capability of PSPs and DDSs in detecting interproximal caries in human teeth, in both dentin and enamel. Histologic sections were the gold standard. This systematic review searched several electronic databases. In addition, Google Scholar and reference lists of the finally included studies were screened. QUADAS-2 was applied to evaluate the risk of bias among included studies. Six studies were finally included; 4 of which were considered homogeneous enough to conduct a meta-analysis. The meta-analysis evaluated 668 interproximal human tooth surfaces. All studies used extracted human teeth ranging from no caries present to caries into dentin. Each tooth was radiographed by both PSP and DDS technologies and then submitted for histologic analysis as the gold standard. Meta-analysis showed that intraoral digital imaging is of high specificity but low sensitivity in the detection of interproximal caries. The sensitivity and specificity for different studies with PSPs varied substantially from 15% to 54% and from 84% to 100%, respectively. Direct sensor analysis sensitivity and specificity ranged from 16% to 56% and from 90% to 100%, respectively. Newer PSP and DDS technologies had statistically significant higher sensitivities, yet the differences in diagnostic capabilities between the older and newer technologies were clinically insignificant. Both digital systems were excellent in identifying surfaces without caries (specificity) but were not sensitive enough to reliably identify interproximal surfaces with caries. Clinicians must therefore remain vigilant in performing a careful clinical examination and other diagnostic tests rather than relying solely on radiographic imaging to diagnose interproximal caries. Knowledge Transfer Statement: This study will help clinicians make an evidence-based decision when deciding which digital radiography system to use when evaluating interproximal caries. Time, patient radiation safety, cost, and image quality are factors to be considered. The performance of the different available digital imaging systems was compared with the current gold standard-a histologic analysis-via meta-analysis.

Changes in temporomandibular joint morphology in class II patients treated with fixed mandibular repositioning and evaluated through 3D imaging: a systematic review.

To estimate the effects of skeletal class II malocclusion treatment using fixed mandibular repositioning appliances on the position and morphology of the temporomandibular joint (TMJ). Two independent reviewers performed comprehensive electronic searches of MEDLINE, EMBASE, EBM reviews and Scopus (until May 5, 2015). The references of the identified articles were also manually searched. All studies investigating morphological changes of the TMJ articular disc, condyle and glenoid fossa with 3D imaging following non-surgical fixed mandibular repositioning appliances in growing individuals with class II malocclusions were included in the analysis. Of the 269 articles initially reviewed, only 12 articles used magnetic resonance imaging and two articles used computed tomography (CT) or cone-beam CT images. Treatment effect on condyle and glenoid fossa was discussed in eight articles. Treatment effect on TMJ articular disc position and morphology was discussed in seven articles. All articles showed a high risk of bias due to deficient methodology: inadequate consideration of confounding variables, blinding of image assessment, selection or absence of control group and outcome measurement. Reported changes in osseous remodelling, condylar and disc position were contradictory. The selected articles failed to establish conclusive evidence of the exact nature of TMJ tissue response to fixed mandibular repositioning appliances.

Assessing the reliability of MRI-CBCT image registration to visualize temporomandibular joints.

OBJECTIVES: To evaluate image quality of two methods of registering MRI and CBCT images of the temporomandibular joint (TMJ), particularly regarding TMJ articular disc-condyle relationship and osseous abnormality. METHODS: MR and CBCT images for 10 patients (20 TMJs) were obtained and co-registered using two methods (non-guided and marker guided) using Mirada XD software (Mirada Medical Ltd, Oxford, UK). Three radiologists independently and blindly evaluated three types of images (MRI, CBCT and registered MRI-CBCT) at two times (T1 and T2) on two criteria: (1) quality of MRI-CBCT registrations (excellent, fair or poor) and (2) TMJ disc-condylar position and articular osseous abnormalities (osteophytes, erosions and subcortical cyst, surface flattening, sclerosis). RESULTS: 75% of the non-guided registered images showed excellent quality, and 95% of the marker-guided registered images showed poor quality. Significant difference was found between the non-guided and marker-guided registration (χ(2) = 108.5; p < 0.01). The interexaminer variability of the disc position in MRI [intraclass correlation coefficient (ICC) = 0.50 at T1, 0.56 at T2] was lower than that in MRI-CBCT registered images [ICC = 0.80 (0.52-0.92) at T1, 0.84 (0.62-0.93) at T2]. Erosions and subcortical cysts were noticed less frequently in the MRI-CBCT images than in CBCT images. CONCLUSIONS: Non-guided registration proved superior to marker-guided registration. Although MRI-CBCT fused images were slightly more limited than CBCT alone to detect osseous abnormalities, use of the fused images improved the consistency among examiners in detecting disc position in relation to the condyle.

Topical contrast agents to improve soft-tissue contrast in the upper airway using cone beam CT: a pilot study.

The purpose of this study is to explore the topical use of radiographic contrast agents to enhance soft-tissue contrast on cone beam CT (CBCT) images. Different barium sulphate concentrations were first tested using an airway phantom. Different methods of barium sulphate application (nasal drops, syringe, spray and sinus wash) were then tested on four volunteers, and nebulized iodine was tested in one volunteer. CBCT images were performed and then assessed subjectively by two examiners for contrast agent uniformity and lack of streak artefact. 25.0% barium sulphate presented adequate viscosity and radiodensity. Barium sulphate administered via nasal drops and sprays showed non-uniform collection at the nostrils, along the inferior and/or middle nasal meatuses and posterior nasal choana. The syringe and sinus wash showed similar results with larger volumes collecting in the naso-oropharynx. Nebulized iodine failed to distribute into the nasal cavity and scarcely collected at the nostrils. All methods of nasal application failed to adequately reach or uniformly coat the nasal cavity beyond the inferior nasal meatuses. The key factors to consider for optimum topical radiographic contrast in the nasal airway are particle size, flow velocity and radio-opacity.

Three-dimensional segmentation of the upper airway using cone beam CT: a systematic review.

The objectives of this study were to systematically review the literature for studies that used cone beam CT (CBCT) to automatically or semi-automatically model the upper airway (including the pharyngeal, nasal and paranasal airways), and to assess their validity and reliability. Several electronic databases (MEDLINE®, MEDLINE In-Process & Other Non-Indexed Citations, all evidence-based medicine reviews including the Cochrane database, and Scopus) were searched. Abstracts that appeared to meet the initial selection criteria were selected by consensus. The original articles were then retrieved and their references were searched manually for potentially suitable articles that were missed during the electronic search. Final articles that met all the selection criteria were evaluated using a customized evaluation checklist. 16 articles were finally selected. From these, five scored more than 50% based on their methodology. Although eight articles reported the reliability of the airway model generated, only three used intraclass correlation (ICC). Two articles tested the accuracy/validity of airway models against the gold standard, manual segmentation, using volumetric measurements; however, neither used ICC. Only three articles properly tested the reliability of the three-dimensional (3D) upper airway model generated from CBCT and only one article had sufficiently sound methodology to test the airway model's accuracy/validity. The literature lacks proper scientific justification of a solid and optimized CBCT protocol for airway imaging. Owing to the limited number of adequate studies, it is difficult to generate a strong conclusion regarding the current validity and reliability of CBCT-generated 3D models.

Clinical and radiographic features of solitary and cemento-osseous dysplasia-associated simple bone cysts.

UNLABELLED: The simple bone cyst (SBC) is a pseudocyst that can occur as a solitary entity in the jaws or may occur in association with cemento-osseous dysplasia (COD). OBJECTIVE: The purpose of this study was to review the clinical and radiographic features of solitary and COD-associated SBCs. METHODS: Archived imaging reports from the Special Procedures Clinic in Oral and Maxillofacial Radiology at the Faculty of Dentistry at the University of Toronto between 1 January 1989 and 31 December 2009 revealed 23 COD-associated SBCs and 68 solitary SBCs. RESULTS: Almost all solitary and COD-associated SBCs were found in the mandible. Furthermore, 87.0% of COD-associated SBCs were found in females in their fifth decade of life (P < 0.001) while solitary SBCs were found in equal numbers in both sexes in their second decade of life (P < 0.005). COD-associated SBCs were also more likely to cause thinning of the endosteal cortex, bone expansion and scalloping of the superior border between teeth (all P < 0.001) than solitary SBCs that are classically described as having these characteristics. Finally, COD-associated SBC demonstrated a loss of lamina dura more often (P < 0.05) than solitary SBCs. CONCLUSIONS: Knowledge of the sporadic association between COD and SBC and their potential radiographic appearances should prevent inappropriate treatment and management of these patients.

Cemento-osseous dysplasia of the jaw bones: key radiographic features.

OBJECTIVE: The purpose of this study is to assess possible diagnostic differences between general dentists (GPs) and oral and maxillofacial radiologists (RGs) in the identification of pathognomonic radiographic features of cemento-osseous dysplasia (COD) and its interpretation. METHODS: Using a systematic objective survey instrument, 3 RGs and 3 GPs reviewed 50 image sets of COD and similarly appearing entities (dense bone island, cementoblastoma, cemento-ossifying fibroma, fibrous dysplasia, complex odontoma and sclerosing osteitis). Participants were asked to identify the presence or absence of radiographic features and then to make an interpretation of the images. RESULTS: RGs identified a well-defined border (odds ratio (OR) 6.67, P < 0.05); radiolucent periphery (OR 8.28, P < 0.005); bilateral occurrence (OR 10.23, P < 0.01); mixed radiolucent/radiopaque internal structure (OR 10.53, P < 0.01); the absence of non-concentric bony expansion (OR 7.63, P < 0.05); and the association with anterior and posterior teeth (OR 4.43, P < 0.05) as key features of COD. Consequently, RGs were able to correctly interpret 79.3% of COD cases. In contrast, GPs identified the absence of root resorption (OR 4.52, P < 0.05) and the association with anterior and posterior teeth (OR 3.22, P = 0.005) as the only key features of COD and were able to correctly interpret 38.7% of COD cases. CONCLUSIONS: There are statistically significant differences between RGs and GPs in the identification and interpretation of the radiographic features associated with COD (P < 0.001). We conclude that COD is radiographically discernable from other similarly appearing entities only if the characteristic radiographic features are correctly identified and then correctly interpreted.