Displacement of dental implants into the focal osteoporotic bone marrow defect: a report of three cases.

Focal osteoporotic bone marrow defect (FOBMD) is a radiolucent area corresponding to the presence of hematopoietic tissue rarely found in the jaws. FOBMD is most commonly located in the mandibular edentulous posterior area of a middle-aged female. From November 2011 to November 2012, we experienced three cases involving removal of implants that had accidentally fallen into the FOBMD area.

Action potential duration restitution kinetics in human atrial fibrillation.

Objectives: We undertook this study to determine whether human atrial fibrillation (AF) relates to steeply sloped action potential duration restitution (APDR) kinetics and whether the spatial nonuniformity of APDR promotes persistence of AF.

Background: A steeply sloped APDR curve is known to be an important determinant of the induction of more complex action potential duration (APD) dynamics and fibrillation.

Methods: Patients with chronic atrial fibrillation (CAF) (n = 18), paroxysmal atrial fibrillation (PAF) (n = 14) and normal control subjects (n = 9) were studied.