Saulo Leonardo Sousa Melo

Comparative diagnostic yield of cone beam CT reconstruction using various software programs on the detection of vertical root fractures.

OBJECTIVES To evaluate the effect on diagnostic yield in the detection of experimentally induced vertical root fractures on cone beam CT images using four dental software program. METHODS 190 single-rooted extracted human teeth were divided into three groups according to the pulp canal status: unrestored (UR), filled with gutta-percha (GP) and restored with a metallic custom post (Post). One-half of the sample of each group was artificially fractured and the segments repositioned. All teeth were scanned on a cone beam CT device at 0.2 mm nominal voxel resolution (i-CAT Platinum; Imaging Sciences International, Hatfield, PA). The data were exported as digital imaging and communications in medicine files and imported into Dolphin Imaging & Management Solutions, v. 11.5 (Patterson Dental Supply Inc., St Paul, MN), InVivoDental, v. 5.0 (Anatomage Inc., San Jose, CA) and Kodak Dental Imaging Software 3D module, v. 2.1.11 (Carestream Health Inc., Rochester, NY) software. Cross-sectional images in the acquisition (using Xoran CAT™, v. 3.0.34 software; Xoran Technologies, Ann Arbor, MI) and additional software were presented to three calibrated oral radiologists who rated the presence or absence of root fracture on a five-point scale. Receiver operating characteristic analysis was performed, and treatment comparisons compared by analysis of variance and pairwise comparisons were performed using Tukeys test at an a priori value of α < 0.05%. RESULTS All dental software performed equally at detecting fractures. Fractures were significantly more difficult to detect when posts were present. CONCLUSIONS The diagnosis of root fracture is software-independent. The presence of an intracanal metallic post significantly decreases the detection of artificially created root fractures.

Mesial Inclination of Impacted Third Molars and Its Propensity to Stimulate External Root Resorption in Second Molars—A Cone-Beam Computed Tomographic Evaluation

PURPOSE To investigate the presence of external root resorption (ERR) in second molars adjacent to horizontally and mesioangular impacted mandibular third molars by cone-beam computed tomography. In addition, patient characteristics (age and gender) and third molar depth were correlated with the presence of ERR. MATERIALS AND METHODS The sample consisted of 116 scans (58 acquired on the i-CAT Classic and 58 on the Picasso-Trio) of 70 women and 46 men (mean age, 23.7 yr). Two observers recorded the presence of ERR in the second molars, inclination and depth of third molars in relation to bone and soft tissues, third molars classification according to Pell and Gregory, and location and severity of ERR. Data were analyzed by analysis of variance, Mann-Whitney test, and χ(2) test. The κ test was used to analyze intraobserver agreement. RESULTS The overall prevalence of ERR was 49.43%. There were no statistically significant differences in the detection of ERR by gender, images from the 2 devices, or third molar inclination (P > .05). The κ test showed excellent reproducibility values (κ = 0.7778). There was a smaller proportion of affected patients 14 to 24 years old and ERR in teeth adjacent to Class C third molars. CONCLUSION Mesially inclined third molars (mesioangular and horizontal) have a greater potential of being associated with ERR in second molars, which was shown by the high prevalence of the condition in the overall sample. Class A and B third molars in patients older than 24 years were more associated with the presence of ERR in adjacent teeth.

Usefulness of cone‐beam CT in the evaluation of a spontaneously healed root fracture case

Horizontal root fractures (HRF) usually affect anterior teeth of male patients as a result of trauma. The consequences can be complex because of combined damage to different tissues, but it has been reported that root fractures undergo healing in majority cases. Diagnosis of HRF must be based on clinical findings, sensibility tests, and radiographic examination. The cone-beam computed tomography (CBCT) has already been proven to be superior among other radiographic modalities for diagnostic imaging of root fractures. However, CBCT in these cases needs to be used in a careful manner, and only when the radiation exposure should be justified by the potential diagnostic benefits and improvement of the treatment results. This case report describes a case of spontaneously healed horizontal root fracture with displacement of the fragments and discusses the usefulness of CBCT in the follow-up of root fractures cases.

Correlation between temporomandibular joint morphology and disc displacement by MRI

OBJECTIVES The aim was to evaluate the morphology of the temporomandibular joints (TMJs) disc and condyle as well as its correlation with disc displacement, using MRI. METHODS 190 TMJs were retrospectively analysed. The condyle morphology of each TMJ was evaluated by two observers using both axial and coronal views, as were their disc morphology and displacement, using sagittal view. Condyle morphology was classified as flat, convex, angled or rounded in the coronal sections and as anterior side flat/posterior side convex, biconvex, anterior side concave/posterior side convex, flat or biconcave in the axial view. Disc morphology was determined as biconcave, biplanar, biconvex, hemiconvex or folded. χ2, Fisher exact and Bonferroni correction tests were used to evaluate the data. ANOVA followed by post hoc Tukeys test was used to evaluate the interaction between age and disc displacement. RESULTS Anterior disc displacement with reduction; convex condyle morphology in the coronal view; anterior side concave/posterior side convex morphology in the axial view; and biconcave discs were found to be the most prevalent findings. An association was observed between disc morphology and disc displacement (p<0.001). No correlation between condyle morphology and TMJ disc displacement was found (p=0.291 for axial and p=0.14 for coronal views). CONCLUSIONS The results of this study suggest that TMJ disc morphology is associated with disc displacement.

Mucopolysaccharidosis: radiographic findings in a series of 16 cases.

OBJECTIVES To investigate the radiographic findings of mucopolysaccharidoses (MPS) on panoramic radiographs in a series of 16 patients. STUDY DESIGN This retrospective cross-sectional study included panoramic radiographs of 16 patients with cytogenetically diagnosed MPS. Two blinded, previously calibrated observers evaluate the presence or absence of the following features: type of dentition; stage of dental age in comparison with chronologic age; delayed exfoliation of deciduous teeth; supernumerary teeth; teeth impaction; enlarged, cyst-like dental crypt; hypercementosis; taurodontism; generalized enamel hypoplasia; enlargement of the bone marrow spaces; thinning of cortical bone; unusual morphology of condyles; and flattening of the condylar head. RESULTS The final sample was composed of 8 MPS IV, 7 MPS VI, and 1 MPS I cases. All patients presented unusual morphology of condyles. Cyst-like dental crypt (75%), taurodontism, and teeth impaction (68.75% each) were also overall common findings. Generalized enamel hypoplasia was exclusively identified in patients with MPS IV (75% of those patients). CONCLUSIONS Radiographic features of oral and maxillofacial manifestations in patients with MPS frequently encountered by dentists may help recognize the disorder. However, because of sample size limitations, it was not possible to infer any statistical relationship between the radiographic features and the types of MPS.

Impact of cone-beam computed tomography scan mode on the diagnostic yield of chemically simulated external root resorption

Introduction: The aim of this in‐vitro study was to evaluate the influence of cone‐beam computed tomography scans on the diagnosis of chemically simulated external root resorption. Methods: One hundred extracted anterior teeth were selected. Subsurface demineralization was induced on a limited area of the apical third of the root of 49 teeth. Each tooth was placed in an empty socket of a partially edentulous dry mandible. Cone‐beam computed tomography images were obtained according to 3 protocols: (1) half scan, 0.40‐mm voxel size; (2) full scan, 0.40‐mm voxel size; and (3) full scan, 0.125‐mm voxel size. Three observers evaluated the images. Sensitivity, specificity, accuracy, and area under the curve were compared with the Cochran Q and Mann‐Whitney U tests. Results: Protocol 3 had the highest sensitivity (81.63%), accuracy (80.67%), and area under the curve (0.807). There were statistically significant differences between protocol 3 and the other 2 protocols (P <0.001). The specificity of protocol 1 (84.97%) was greater than that of protocols 2 (69.93%) and 3 (79.74%); however, a statistically significant difference was found only between protocols 1 and 2 (P = 0.005). Conclusions: A more dedicated, high‐resolution scan should be acquired when one intends to investigate the early stage of external root resorption during orthodontic treatment. However, this does not imply that all orthodontic patients should be subjected to high‐dose cone‐beam computed tomography scans. HighlightsDegree of rotation (half and full scan) with the same voxel size (0.4 mm) did not differ.Considerable differences were seen between those and the smallest voxel size (0.125 mm).A dedicated, high‐resolution scan is recommended when investigating early stage external root resorption.

Quantitative assessment of image artifacts from root filling materials on CBCT scans made using several exposure parameters

Purpose To quantify artifacts from different root filling materials in cone-beam computed tomography (CBCT) images acquired using different exposure parameters. Materials and Methods Fifteen single-rooted teeth were scanned using 8 different exposure protocols with 3 different filling materials and once without filling material as a control group. Artifact quantification was performed by a trained observer who made measurements in the central axial slice of all acquired images in a fixed region of interest using ImageJ. Hyperdense artifacts, hypodense artifacts, and the remaining tooth area were identified, and the percentages of hyperdense and hypodense artifacts, remaining tooth area, and tooth area affected by the artifacts were calculated. Artifacts were analyzed qualitatively by 2 observers using the following scores: absence (0), moderate presence (1), and high presence (2) for hypodense halos, hypodense lines, and hyperdense lines. Two-way ANOVA and the post-hoc Tukey test were used for quantitative and qualitative artifact analysis. The Dunnet test was also used for qualitative analysis. The significance level was set at P<.05. Results There were no significant interactions among the exposure parameters in the quantitative or qualitative analysis. Significant differences were observed among the studied filling materials in all quantitative analyses. In the qualitative analyses, all materials differed from the control group in terms of hypodense and hyperdense lines (P<.05). Fiberglass posts did not differ statistically from the control group in terms of hypodense halos (P>.05). Conclusion Different exposure parameters did not affect the objective or subjective observations of artifacts in CBCT images; however, the filling materials used in endodontic restorations did affect both types of assessments.

Performance of 5 different displays in the detection of artificial incipient and recurrent caries-like lesions

OBJECTIVES The aim of this study was to assess whether auto-calibrating medical-grade monitors perform better than off-the-shelf monitors and tablet computers in detecting artificial incipient and recurrent caries-like lesions. STUDY DESIGN Sixty extracted teeth (30 premolars and 30 molars) were selected. All molars received class II amalgam and composite restorations. A 7-mm2 area on the crowns of half of the teeth was demineralized. Phantoms consisting of 4 teeth were created. Three observers using a 5-point scale evaluated digital periapical radiographs for the presence of caries on 5 displays: 2 autocalibrating medical-grade monitors, 2 tablets, and 1 off-the-shelf monitor. Sensitivity, specificity, accuracy, and receiver operating curve data were calculated and verified through analysis of variance and Tukey tests. Observer agreements were assessed using Cohens κ test. RESULTS Intraobserver agreement ranged from 0.347 to 0.612 (molars) and 0.617 to 0.811 (premolars). Interobserver agreement ranged from 0.239 to 0.559 (molars) and 0.657 to 0.858 (premolars). The performances of tablets and the off-the-shelf monitor were similar to medical monitors when the same tooth groups were compared. Medical-grade monitors presented fewer statistically significant differences when different lesions where compared within the same display and restorative material. CONCLUSIONS Evaluations of similar lesions were not significantly different among the 3 types of displays. However, the autocalibrating medical-grade monitors performed better when incipient and recurrent lesions were compared.

The Upper Airway

The upper airway (UA) is the mucosal lined fibro-muscular tube that connects the nasal and oral cavities with the larynx and esophagus. It performs several different physiologic functions, including vocalization, deglutition, and respiration. Clinicians must be able to recognize incidental findings of non-significance, particularly in children such as the variability in the size of the tonsils and adenoids and the tendency of these structures to reduce in size with age. In older individuals, clinicians should recognize features and preferred locations of specific entities of significance such as the mass effect of nasopharyngeal carcinoma occurring most often in the fossa of Rosenmueller and the extension of both sinus and nasal lesions leading to reduced luminal dimensions or obstruction of the naso-, oro-, or hypopharyngeal airway.

CBCT Imaging of Sinonasal Disease

In dental and maxillofacial cone beam computed tomographic (CBCT) imaging of the mid-facial region, it is highly likely that clinicians will observe various radiologic findings involving the paranasal sinuses. Dentists using CBCT are responsible for interpreting not only the radiologic findings needed for a specific dental task (e.g., implant treatment planning, detect periapical pathologies of posterior teeth in the maxilla) but also the structures, anatomic variability, and common diseases associated with the maxillary sinus. The purpose of this Chapter is to describe specific radiologic patterns indicative of sinonasal pathology, recommend CBCT specific imaging and display protocols, and provide guidelines for systematic interpretation of the paranasal sinuses on CBCT.