ORAL AND MAXILLOFACIAL PATHOLOGY (OMFP)
HISTOPATHOLOGY SERIES
David E. Klingman, Lt Col, USAF, DC
Series 3 – Bone
This series consists of images of hard tissues; it is designed to highlight normal and abnormal bone and (osteo)cementum:

Dense bone
(2)

Mature osteocementum
(2)

Osteomyelitis
(3)

Acute osteomyelitis
(2)

Osteonecrosis
(1)

Carious tooth
(1)
this specimen was from a dense bone island and consists of dense viable bone
an osteon unit is identifiable at higher magnification
bone and cementum bear similarity and may be admixed, particularly in maturing
fibro-osseous lesions as in this case [radiographically these would be radiopaque]
there is granulation tissue noted in the center; these maturing ‘BFOLs’ become avascular
with time and may necrose and form involucrum (dead bone that has not exposed to the
oral cavity or sequestrum (bone that has exposed to oral environment and/or been
‘expelled’)
osteomyelitis by definition must involve inflammation within the bone; it may be either
acute or chronic; the diagnosis is made with some hesitancy by many pathologists and
may require clinical signs and symptoms and significant inflammation (since the implied
treatment may be long-term antibiotics, surgical debridement and/or resection as in this
case)
the acute inflammatory cells (neutrophils) and multinucleated osteoclasts (inside the so
called Howship’s lacunae are easily identified
this was from a case of bisphosphonate-related osteonecrosis; the bone is non-vital (the
lacunae are enlarged and no osteocytes are identified) and bacterial colonies are present
(as pale purple staining amorphous material)
the two panels demonstrate bacterial colonies infiltrating the dentinal tubules
Notes:
Viable bone, by definition, requires the presence of osteocytes within the lacunae; the decalcification procedure (immersion of the
specimen in a potent acid in order to soften the specimen for cutting and staining) may mimic necrosis as the osteocytes may be lost during
the process.
Non-viable bone, such as in osteonecrosis or osteoradionecrosis, will by definition be absent of osteocytes; clinical history of
bisphosphonate or antimetabolite exposure or of radiation therapy to the jaw should be included in the biopsy request and patient history
Bone and cementum may appear similarly histologically; cementum, however, will typically stain more basophilic (blue-purple) and in
mixed lesions, cementum will often demonstrate reversal lines (alternating areas of pink and linear purple staining) mimicking the
cementum seen on the surface of a normal tooth root [refer back to Series 1 images demonstrating the tooth/cementum/PDL/bone]
The views and opinions expressed in this presentation are those of the author(s) and do not reflect official policy or position of the United States Air Force,
Department of Defense, or US Government.