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.

Evaluation of temporomandibular joint disk displacement and its correlation with pain and osseous abnormalities in symptomatic young patients with magnetic resonance imaging.

OBJECTIVE: To evaluate the occurrence of temporomandibular joint disk displacement and its correlation with pain and osseous abnormalities using magnetic resonance imaging (MRI) in patients under 21 years of age. STUDY DESIGN: MRI images in open- and closed-mouth positions from 102 patients, under 21 years of age (mean age 17 years), were studied retrospectively. Patients were divided into six groups according to the disk-condyle relationship. Chi-square, Marascuilo procedure, and Cochran-Mantel-Haenszel tests were used to evaluate the relationships among pain, abnormalities, and the groups. RESULTS: There was a statistically significant correlation between bilateral disk displacement without reduction and pain (P = .011), and osseous changes (P < .0001). There was no proven link between pain and osseous abnormality (P = .414). CONCLUSION: Young patients are susceptible to all stages of disk displacement. There was a strong correlation only between each variable (osseous abnormalities and pain) and the most severe stage of disk displacement (bilateral disk displacement without reduction).

Unilateral bony ankylosis of the temporomandibular joint in a case of ankylosing spondylitis.

BACKGROUND: Ankylosing spondylitis (AS) is a chronic inflammatory disease with multiple articular and para-articular involvement that has a predilection for the axial skeleton. In spite of its high prevalence, ankylosis secondary to AS is a rare condition. CASE REPORT: A 31-year-old male diagnosed with AS was referred for computed tomography (CT) of the temporomandibular joint (TMJ) due to severe mouth opening limitation. The patient had a 16-year medical history of AS and sought assistance due to TMJ pain and incapacity to open his mouth. RESULTS: Previous bony scintigraphy revealed involvement of the spine, sacroiliac joints, right knee, and left TMJ. Magnetic resonance imaging revealed erosion of the left condyle and posterior slope of the articular eminence, and a mass of heterogeneous signal intensity between these structures. The left condyle also presented sclerosis/edema of the bone marrow and the disk could not be identified. Sagittal and coronal CT images showed moderate alterations of the TMJ on the right side. On the left side, the images displayed markedly eroded condyle and mandibular fossa, and a bony mass resulting in ankylosis of the osseous components of the joint. CONCLUSION: TMJ ankylosis in AS patients is rare and very few reports have presented imaging features of the condition through advanced diagnostic techniques.

Uncommon dentigerous cyst related to a maxillary lateral incisor in a 03-year-old boy.

BACKGROUND: The dentigerous cyst is usually defined as a cystic cavity that surrounds the crown of an unerupted tooth on the cementoenamel junction. The present article reports a case of an uncommon dentigerous cyst, highlighting its clinical, radiographic and surgical characteristics and discussing the aspects related to its development in infancy. CASE REPORT: A 03-year-old boy patient presented with an extensive radiolucid area involving the crown of the right maxillary lateral incisor. A surgical excision was performed. Anatomopathological examination revealed a cystic tissue with a fibrous wall surrounded by nonkeratinized stratified squamous oral epithelium, without atypia. CONCLUSION: It is possible that the dentigerous cyst grows in the dental germ in any stage of development and not only in the follicle of a tooth with calcified crown attached to the cementoenamel junction.