You have microscopic evidence of ischemic osteonecrosis (literally, "dead
bone from poor blood flow"😉, a bone marrow disease with either dead bone or
bone marrow that has been slowly strangulated or nutrient-starved. There are
a number of local and systemic problems capable of producing this bone
disease (Table 1), but more than 4 of every 5 patients with osteonecrosis
have a problem, usually inherited, of excessive production of blood clots in
their blood vessels (Table 2). These are not normally picked up with routine
blood studies. Bone is particularly susceptible to this problem and develops
greatly dilated blood vessels, increased, often painful, internal pressures,
stagnation of blood, even infarctions (completely blocked vessels). This
hypercoagulation problem might be suggested by a family history of stroke
and heart attacks at an early age (less than 55 years), hip replacement or
"arthritis" (especially at an early age), and deep vein thrombosis. Chronic
fatigue syndrome and fibromyalgia are also associated with excess
coagulation and are frequently found in patients with osteonecrosis, but the
significance of this association is not yet known. The jaws have a special
problem with this disease because, once damaged, the diseased bone is poorly
able to withstand low-grade infections from tooth and gum bacteria. Also,
when a dentist works on a tooth he or she uses strong chemicals
(vasoconstrictors, e.g., epinephrine) designed to make local blood vessels
smaller and thus keep the local anesthetic in place longer. For someone who
already has a problem with poor blood flow through the jaws, this may be
disastrous.
Regardless of the underlying cause, the bone develops either a fibrous
marrow (fibers can live in nutrient starved areas), a greasy, dead fatty
marrow ("wet rot"😉, a very dry, sometimes leathery marrow ("dry rot"😉, or a
completely hollow marrow space ("cavitation"😉. Any bone can be affected, but
the hips, knees and jaws are most often involved. Pain is often severe but
about 1/3 of patients do not experience pain. The body has trouble healing
itself from this disease, but about 1/3 of cases do indeed heal themselves.
For the others, experience has shown that surgically removing the damaged
marrow, usually by scraping with curettes, will eliminate the problem (and
the pain) in almost 3/4 of patients with jaw involvement. Repeat surgeries,
usually smaller procedures than the first, may be required, and almost a
third of jawbone patients will need surgery in one or more other parts of
the jaws because the disease so frequently has "skip" lesions, i.e. multiple
sites in the same or similar bones, with normal marrow between. In the hip,
at least half of all patients will get the disease in the opposite hip over
time; this phenomenon occurs in the jaws as well. Recently, it has been
found that some osteonecrosis patients respond to anticoagulation therapies.