Stafne's bone defect in a metastatic prostate cancer patient: A diagnostic conundrum.

Stafne's bone defect (SBD) is an uncommon bone alteration that affects the mandible and usually presents as an asymptomatic radiolucency located in the posterior region of body or angle of the mandible, below the alveolar canal. Although clinical and radiographic features are more often sufficient for the diagnosis, other lesions and bone alterations have been described in the differential diagnosis and may lead to a misinterpretation and an incorrect diagnosis. Herein, we report a case of an 89-yearold man with metastatic prostate cancer to multiple bones, presenting an asymptomatic solitary well-defined radiolucent image on the right side of the posterior body of the mandible, in close contact with its inferior border. A bone depression was confirmed by computed tomography scans of the mandible and a metastatic inclusion was ruled out by bone scintigraphy with a final diagnosis of SBD. The aim of this report was to highlight the importance of differentiating SBD from metastases in cancer patients and to reinforce the usefulness of multiple imaging modalities in the differential diagnosis of SBD. Key words:Stafne's bone defect, Mandible, Depression, Metastases, Imaging modalities.

In situ analysis of gelatinolytic activity in human dentin.

Matrix metalloproteinases (MMPs) such as gelatinases are differentially expressed in human tissues. These enzymes cleave specific substrates involved in cell signaling, tissue development and remodeling and tissue breakdown. Recent evidences show that gelatinases are crucial for normal dentin development and their activity is maintained throughout the entire tooth function in the oral cavity. Due to the lack of information about the exact location and activity of gelatinases in mature human dentin, the present study was designed to examine gelatinolytic levels in sound dentin. In situ zymography using confocal microscopy was performed on both mineralized and demineralized dentin samples. Sites presenting gelatinase activity were identified throughout the entire biological tissue pursuing different gelatinolytic levels for distinct areas: predentin and dentinal tubule regions presented higher gelatinolytic activity compared to intertubular dentin. Dentin regions with higher gelatinolytic activity immunohistochemically were partially correlated with MMP-2 expression. The maintenance of gelatinolytic activity in mature dentin may have biological implications related to biomineralization of predentin and tubular/peritubular dentinal regions, as well as regulation of defensive mechanisms of the dentin-pulp complex.

Oral and maxillofacial manifestations of chronic kidney disease-mineral and bone disorder: a multicenter retrospective study.

OBJECTIVE: To describe the oral and maxillofacial manifestations of patients diagnosed with chronic kidney disease-mineral and bone disorders. STUDY DESIGN: Over a 13-year period, clinicopathologic data of patients diagnosed with CKD-MBD who had oral and maxillofacial alterations were retrieved from the files of 4 Brazilian institutions. Data included clinical, radiographic, microscopic, and biochemical findings; treatment employed; and follow-up status. RESULTS: Twenty-one cases were identified, with 13 patients diagnosed as brown tumor of hyperparathyroidism (BTH) and 8 as osteitis fibrosa/renal osteodystrophy (OF/RO) (4 of them clinically consistent with Sagliker syndrome). The mean age was 32.7 years, and the mandible was the most affected site (42.8%). OF/RO had an ill-defined "ground glass" radiographic appearance, and BTH produced well-defined radiolucent images. Biochemically the following mean values were obtained: parathormone 1511.07 pg/mL, calcium 9.25 mg/dL, phosphorus 5.19 mg/dL, alkaline phosphatase 941.55 U/L, urea 125.42 mg/dL, and creatinine 7.14 mg/dL. Treatment comprised vitamin D and calcium intake, parathyroidectomy, hemodialysis, renal transplantation, and local surgery. During follow-up, 5 patients with BTH were free of lesions, whereas 2 affected by OF/RO/Sagliker syndrome died. CONCLUSIONS: Oral and maxillofacial manifestations of BTH and OF/RO are uncommon, but they can be associated with an important life-threatening scenario.