Reliability of magnetic resonance imaging on detecting degenerative bone changes of the temporomandibular joint.

PURPOSE: To evaluate and describe the most frequent TMJ degenerative bone alterations on MRI and CT and to determine the accuracy, sensitivity, and specificity of MRI. METHODS: Images of 80 subjects were selected and evaluated from a database and 57 were selected. The subjects were submitted to CT and MRI exams (each subject on the same day). The joints were evaluated in the sagittal and coronal planes under closed mouth position. Each individual parameter was scored as absent or present. Absolute and relative frequencies were obtained and the Kappa concordance index test and equality of two proportions were used. To correlate the presence of bone alterations, the Chi-Square test was performed. A significance level of 0.05 (5%) was defined, with 95% of statistical confidence interval. RESULTS: Of the 57 subjects, (47 female, 10 male), the ages ranged from 18-83 years (mean 43 years). The intra and inter-rater agreement tests demonstrated reliability among the examiners for all variables analyzed on MRI and CT. CLINICAL SIGNIFICANCE: MRI is a reliable and valid method for observing bone changes in the TMJ, with the advantage of non-exposure to radiation and cost-effectiveness due to the use of only one exam.

A comparison of conventional and diffusion-weighted magnetic resonance imaging in the diagnosis of sialadenitis and pleomorphic adenoma.

OBJECTIVES: The aim of this study was to compare the efficacy of conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in correctly identifying the presence of disease in the major salivary glands and correctly distinguish sialadenitis from pleomorphic adenoma. STUDY DESIGN: Twenty-one patients diagnosed with unilateral sialadenitis or pleomorphic adenoma were selected. The nonaffected contralateral glands were also analyzed. T1- and T2-weighted MRI and DWI were obtained using spin-echo pulse sequences with a 1.5 Tesla MRI device. The diagnostic performance of 3 observers was evaluated for detection of salivary gland alterations and differentiation between sialadenitis and pleomorphic adenoma based on evaluation of MRI in comparison with DWI. RESULTS: Intra-and interobserver reliability ranged from 0.86 to 0.94. DWI demonstrated greater sensitivity and accuracy values compared with MRI for both detection of disease and differentiation of sialadenitis from pleomorphic adenoma, with specificity values that were greater than or equal to those of MRI. DWI yielded significantly higher diagnostic odds ratios compared with MRI for both identification of disease and differentiation between lesions. CONCLUSIONS: DWI demonstrated better diagnostic performance in the detection of alterations in the salivary glands and in differentiating between sialadenitis and pleomorphic adenoma compared with conventional T1 and T2-weighted MRI.

Botulinum Toxin Type-A as an alternative treatment for gummy smile: a case report.

In some cases of dentofacial deformities such as vertical maxillary excess, administration of botulinum toxin has been used as an effective minimally invasive technique to improve the aesthetic disorder of gummy smile. This article presents a case of a woman with excessive gingival exhibition during the smile related to vertical maxillary excess and hyperactive upper lip elevator muscles. This patient was treated using botulinum toxin type A (BT) to camouflage the deformity and improve her facial aesthetic. This therapeutic option proved to be effective and should be a good alternative for patients.

Should incidental findings in diagnostic imaging be reported?

BACKGROUND: Recent improvements in image quality have contributed to an increasing number of incidental findings (IF). Also called as "incidentalomas", this generic term refers to an entity discovered unexpectedly on an imaging examination performed for other reason. Commonly, normal variants, minor developmental anomalies and imaging artifacts are described as potential pathology. Some IF were reported in magnetic resonance imaging (MRI) exam of temporomandibular joint (TMJ), including IF in the brain, maxillary sinus, ethmoidal cells, mastoid cells, salivary glands, muscles. The aim of this study is to evaluate the prevalence of IF on MRI of TMJ from Japanese patients. METHODS: An image archive from 872 patients referred to MRI evaluation due to TMJ symptomatology was assessed. Three experienced radiologists evaluated all images, and the final diagnosis was achieved by consensus. The data regarding IF was recorded, considering only tumor and tumor-like lesions. RESULTS: A total of 12 (1.38%) of tumor and tumor-like lesions were observed from all 872 MRI exams evaluated. The most frequent lesion was arachnoid cyst (0.45%), followed by neoplastic lesions (0.22%). CONCLUSIONS: The question "should every IF be reported?" is still difficult to answer. Relevant IF are rare, and radiologists are expected to be reasonable: think about the adverse effects of reporting an IF, and, based on their own judgment, choose for a positive or a negative answer.

Diffusion-weighted MRI for differentiation between sialadenitis and pleomorphic adenoma.

OBJECTIVES: The aim of this study was to compare apparent diffusion coefficient (ADC) values from diffusion-weighted MRI (DWI) among normal salivary glands, cases with sialadenitis and cases with pleomorphic adenoma of major salivary glands. METHODS: 22 patients (totalling 44 major salivary glands) diagnosed with either unilateral sialadenitis (on either parotid or submandibular gland) or parotid gland pleomorphic adenoma were selected. Contralateral non-affected glands (normal) were also analyzed. DW images were achieved using a spin-echo pulse sequence with a 1.5-T MRI device. Mean ADC values were compared among the three groups analyzed (contralateral normal glands, sialadenitis and pleomorphic adenoma). RESULTS: The mean ADC values were significantly higher in cases of parotid sialadenitis (p = 0.001), but not in cases of submandibular sialadenitis (p = 0.466), as compared with the contralateral non-affected glands. Cases of pleomorphic adenoma presented the highest ADC values of the study. In addition, one-way ANOVA test revealed a significant difference among the three groups of parotid glands analyzed. CONCLUSIONS: Within the limitations of this study, the present results suggest that DWI allows for differentiation between parotid sialadenitis and pleomorphic adenoma.

Fibrous Dysplasia Characterization Using Lacunarity Analysis.

Fibrous dysplasia (FD) is a developmental anomaly in which the normal medullary space of the affected bone is replaced by fibro-osseous tissue. This condition is typically encountered in adolescents and young adults. It affects the maxillofacial region and it can often cause severe deformity and asymmetry. Therefore, accurate diagnosis is critical to determine the appropriate treatment of each case. In this sense, computed tomography (CT) is a relevant resource among the imaging techniques for correct diagnosis of this condition. Thus, in this paper, we propose to analyze fibrous dysplasia through its texture pattern. To accomplish this task, we propose to use lacunarity analysis, a multiscale method for describing patterns of spatial dispersion. Results indicated lower lacunarity values for fibrous dysplasia in comparison to normal bone samples, an indication that their texture images are more homogeneous, and a high separability between the classes when using principal component analysis (PCA) and decision trees for statistical analysis.

Odontogenic glandular cyst: a case report.

Glandular Odontogenic Cyst (GOC) is a rare developmental cyst of the jaws. The histological features of GOC strongly suggest an origin from the remains of dental lamina. Radiographically, GOC presents as well-defined radiolucencies with uni- or multilocular appearance. A case of GOC in a 54-year-old black female is presented here. Clinical, histological and imaging features were evaluated. Due to the high tendency of recurrence and the aggressive potential of GOC, careful clinical and radiological evaluation must be carried out. CT scans are recommended because they provide accurate information about locularity of the lesion, cortical integrity, expansion of the lesion and involvement of the contiguous soft tissue.

Odontoameloblastoma: report of two cases.

Odontoameloblastoma (OA) is a very rare mixed odontogenic neoplasm, characterized by the simultaneous occurrence of an ameloblastoma and a compound or complex odontoma in the same tumor mass. To date, less than 50 cases of OA and/or ameloblastic odontoma have been reported in the English dental literature. This neoplasm was called ameloblastic odontoma. The term OA was included in the 1971 WHO classification. In this study, we present two cases of OA, which we hope will contribute to the awareness and knowledge of surgeons regarding the existence of this odontogenic tumor so that patients having it may be treated and followed-up properly.