Predominantly normal mandible (first molar region; 76 y/o female). A relatively normal bone marrow in older individuals has a uniform white/yellow color with a salmon-colored, glistening alveolar nerve (running left to right in midportion of photo).  Small hollow spaces, as seen in the upper central area here, are probably common and related to chronic ischemia, but by definition the cavitation must be 0.5 cm. or more in diameter before it can be considered part of ischemic disease.