Assessment of using digital manipulation tools for diagnosing mandibular radiolucent lesions.

OBJECTIVE: The purpose of this study was to analyse the use of digital tools for image enhancement of mandibular radiolucent lesions and the effects of this manipulation on the percentage of correct radiographic diagnoses. METHODS: 24 panoramic radiographs exhibiting radiolucent lesions were selected, digitized and evaluated by non-experts (undergraduate and newly graduated practitioners) and by professional experts in oral diagnosis. The percentages of correct and incorrect diagnoses, according to the use of brightness/contrast, sharpness, inversion, highlight and zoom tools, were compared. All dental professionals made their evaluations without (T1) and with (T2) a list of radiographic diagnostic parameters. RESULTS: Digital tools were used with low frequency mainly in T2. The most preferred tool was sharpness (45.2%). In the expert group, the percentage of correct diagnoses did not change when any of the digital tools were used. For the non-expert group, there was an increase in the frequency of correct diagnoses when brightness/contrast was used in T2 (p=0.008) and when brightness/contrast and sharpness were not used in T1 (p=0.027). The use or non-use of brightness/contrast, zoom and sharpness showed moderate agreement in the group of experts [kappa agreement coefficient (κ) = 0.514, 0.425 and 0.335, respectively]. For the non-expert group there was slight agreement for all the tools used (κ ≤ 0.237). CONCLUSIONS: Consulting the list of radiographic parameters before image manipulation reduced the frequency of tool use in both groups of examiners. Consulting the radiographic parameters with the use of some digital tools was important for improving correct diagnosis only in the group of non-expert examiners.

Evaluation of the lateral pterygoid muscle using magnetic resonance imaging.

OBJECTIVES: The aims of this study were to evaluate the visibility of the lateral pterygoid muscle (LPM) in temporomandibular joint (TMJ) images obtained by MRI, using different projections and to compare image findings with clinical symptoms of patients with and without temporomandibular disorders (TMD). METHODS: In this study, LPM images of 50 participants with and without TMDs were investigated by MRI. The images of the LPM in different projections of 100 TMJs from 35 participants (70 TMJs) with and 15 participants (30 TMJs) without clinical signs and symptoms of TMD were visible and analysed. RESULTS: The oblique sagittal and axial images of the TMJ clearly showed the LPM. Hypertrophy (1.45%), atrophy (2.85%) and contracture (2.85%) were the abnormalities found in the LPM. TMD signs, such as hypermobility (11.4%), hypomobility (12.9%) and disc displacement (20.0%), could be seen in TMJ images. Related clinical symptoms, such as pain (71.4%), articular sounds (30.4%), bruxism (25.7%) and headache (22.9%), were observed. CONCLUSIONS: Patients with TMD can present with alterations in the LPM thickness. Patients without TMD also showed alterations, such as atrophy and contracture, in TMJ images. Recognition of alterations in the LPM will improve our understanding of clinical symptoms and pathophysiology of TMD, and may lead to a more specific diagnosis of these disorders.

Conventional and indirect digital radiographic interpretation of oral unilocular radiolucent lesions.

OBJECTIVES: To compare the diagnostic processes for the main unilocular radiolucent lesions of the mandible in the presence of the following variables: conventional and digital radiography, specialization of the examiner and type of lesion. METHODS: Twenty-four panoramic radiographs were selected from the archives of the AC Camargo Hospital (São Paulo, Brazil), aiming at comparing the diagnostic processes for similar unilocular radiolucent lesions of the mandible, with the following histopathological diagnosis: six ameloblastomas, six dentigerous cysts, six keratocysts and six traumatic bone cysts. The radiographs were scanned and processed using the Trophy 2000 software. Three specialists, each from four related areas (pathologists, stomatologists, radiologists and oral surgeons), randomly evaluated the radiographs before and after digitalization. RESULTS: The kappa statistic showed a high level of agreement between results obtained using the two radiographic techniques. This means that, in general, the examiners diagnosed the same cases correctly or incorrectly regardless of the method used. CONCLUSIONS: Based on generalized estimating equations, it was concluded that the probability of correct diagnosis does not depend on the kind of lesion, on the radiographic technique or on the specialization of the examiner. In view of the differing opinions of the specialists regarding the diagnostic validity of some software features available and of the results obtained in indirect digital technique, it may be reasonable to reconsider its use for diagnosis of bone pathology.

Dento-maxillo-facial radiology as an aid to human identification.

Analysis of some anatomical structures of the face using radiographs is fundamental for human identification. The position of the postmortem skull relative to the radiographic machine and the film, as well as the exposure time, are the greatest problems found by the forensic dentist. In view of this fact, some recognised radiographic techniques that are used in vivo must be adapted. This paper shows that simple devices can make the process easier and that variation of kVp or exposure time in different situations may increase the quality of the radiographs.

[Ameloblastic transformation of an odontogenic cyst]. / Transformação ameloblástica de um cisto odontogênico.

The author relate a case of ameloblastic changing in an odontologenic cyst located in the anterior region of the mandible, in a man fifty-four years old. They comment the importance of a complete examination when someone finds a pathology.