Effect of different exposure times on caries detection and pixel value in a wireless digital system.

OBJECTIVES: : The aim of this study was to assess, using the CDR Wireless®, the effect of different exposure times on caries detection and pixel intensity values. MATERIALS AND METHODS: Forty teeth were x-rayed using a Schick CDR Wireless sensor at eight different exposure times - 0.06, 0.10, 0.13, 0.16, 0.20, 0.25, 0.30, and 0.32 s. Four observers evaluated the images for presence of carious lesions scoring proximal surfaces of each tooth on a 5-point scale. Scores were compared to histological sections of the teeth. Accuracy was evaluated by means of ROC curve analysis. Radiographs of an aluminum step wedge were obtained using the same eight exposure times. Pixel intensity measurements were obtained, and mean pixel values were statistically analyzed using linear regression. RESULTS: The Az for each exposure time varied from 0.53 to 0.62. Two-way analysis of variance and Tukey test demonstrated that the exposure time of 0.25 s presented the best result and was significantly higher than 0.30 s and 0.35 s. In regard to mean pixel values, two different behaviors were observed, and the exposure time of 0.20 s presented mean pixel values in both phases. CONCLUSION: The performance of the exposure times from 0.06 s to 0.25 s was satisfactory for proximal caries detection, and 0.25 s is the best as indicated for this finality. CLINICAL RELEVANCE: Considering that a reduction of exposure time represents a reduction of patient exposure dose, and this reduction cannot neglect image quality, the behavior of any digital system must be carefully evaluated.

Multidisciplinary Treatment of a Double First Mandibular Premolar.

Gemination aka twinning and fusion, are rare occurrences in posterior mandibular teeth, often requiring endodontic and surgical treatment for functional, orthodontic or cosmetic reasons. The diagnosis and design of a precise treatment plan in cases involving double teeth are in most cases challenging. The purpose of this case report is to describe a successful multidisciplinary treatment protocol for a double tooth. Upon completion of the endodontic, restorative and orthodontic treatments, the clinical and radiographic three-year follow-up revealed that the rest of the transected premolar showed evidence of healing of the supporting tissues and satisfactory cosmetic result.

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.

Morphofunctional features of the temporomandibular joint / Aspectos morfofuncionales de la articulación temporomandibular

This article focuses on important morphofunctional features of the temporomandibular joint, particularly those related to the ultrastructure and anterosuperior attachment of the joint capsule and condylar position at the end of the mouth-opening movement.

Se focaliza importantes aspectos morfofuncionales de la articulación temporomandibular, especialmente aquellos relacionados a la ultraestructura e inserción antero-superior de su cápsula articular y la posición final del cóndilo, en el movimiento de apertura máxima bucal.