Diseases of the Jawbones
DENS 3702, Spring Semester
Basic objectives for individual lesions:
1. Identify the cause (etiology; pathogenesis), cell or tissue of origin, and frequency (prevalence
rate)
2. List the predilection GAL (Gender predilection, Age predilection, Location predilection)
3. Describe the typical clinical appearance, unusual clinical variants, and look-alike lesions
4. Describe the basic microscopic features
5. Describe the usual biologic behavior (pathophysiology) and prognosis without treatment, and describe the typical treatment(s) and the prognosis with such treatment(s)
6. Describe unique variants, special features, or unique problems
Osteogenesis imperfecta:
1. Etiology: mutation in genes of type I collagen formation (autosomal dominant, some autosomal recessive); 1/8,000 births
2. GAL:
– None
– Infant and young child
– Teeth (opalescent dentin)
3. Clinical: Bowing, angulation, deformity of long bones; pathologic fracture; Wormian skull; osteopenia;
– Blue or gray or brown “translucent” crowns identical to dentinogenesis imperfecta
– Maybe shell teeth
– Fracture of crowns; maxillary hypoplasia
– Rarely, mixed radiolucent/opaque areas of jaws; hearing deficits
– Hypermobile joints; blue sclera; capillary fragility (pathologic bleeds)
4. Micro: Immature, irregularly shaped bony trabecula in fibrous background; diminished marrow; teeth have small pulps (shell teeth have large pulps)
5. Treat: Cautious behavior to prevent fracture; C-section for birth; shorten dental crowns; overdenture
6. Special: 4 types of disease:
– Type I: most common, mildest form; blue sclera throughout life; AD inheritance
– Type II: most severe (90% are stillborn or die shortly after birth); both AD & AR inheritance
– Type III: second most severe form; usually noticed after 6 months; sclera often normal; most die before adulthood (usually from cardiopulmonary problems from kyphoscoliosis);
both AD & AR inheritance
– Type IV: fractures in 50% at birth; blue sclera usually fades with time; AD inheritance
Osteopetrosis:
1. Etiology: inherited failure of osteoclastic function (number of osteoclasts is normal or high) > no bone resorption > gradual thickening of trabecula and cortex & anemia from less marrow space; prevalence rate: 1/100,000 persons
2. GAL: none; infancy (except adult onset type); none
3. Clinical: Slow opacification and decreased blood flow to bone (painful?), often with osteomyelitis which fails to heal (primarily a jaw problem), hearing loss and vision loss and facial palsy from crimping of nerves as they pass thru foramina; delayed or stopped tooth eruption; pathologic fractures
4. Micro: Thick lamellar bone forming concentric rings as it fills marrow spaces; thick cortex
5. Treat: Antibiotics to counter fewer hematopoietic cells; treat anemias if possible; try to prevent dental infection; hyperbaric therapy; a variety of medical therapies are tried.
6. Special: Two major types:
– Infantile osteopetrosis (malignant osteopetrosis): severe (usually die in first decade);
most common form; AR inheritance.
–Adult osteopetrosis (benign osteopetrosis): not severe (usually no marrow deficit); boneain is common; AD inheritance
Cleidocranial dysplasia:
1. Etiology: defective CBFA1 gene (chromosome 21) which guides osteoblastic differentiation and appropriate bone formation; AD inheritance with 40% spontaneous mutations
2. GAL: none; childhood and teenage years; clavicle
3. Clinical: missing or partially missing clavicles; drooping shoulders; frontal and parietal bossing; delayed closure of skull sutures (wormian bones); failure of permanent teeth to erupt; supernumerary teeth; hypoplastic alveolar development.
4. Micro: Bone looks normal; permanent teeth lack secondary cementum.
5. Treat: Surgical exposure and orthodontic repositioning of teeth; extraction of teeth with denture construction.
Focal osteoporotic marrow defect:
1. Etiology: Unknown, perhaps chronic local ischemia, perhaps demands of body for blood cells
2. GAL: female; middle-aged and older; third molar and retromolar areas, especially mandible, especially in old extraction sites
3. Clinical: poorly defined radiolucency, perhaps with portions of residual socket; may be tender or painful; no cortical expansion.
4. Micro: marrow is usually fatty, may be hematopoietic, and bony trabecula are thin and widely spaced.
5. Treat: None required unless painful, but usually conservative curettage is done to rule out lymphoma or sarcoma of bone.
Massive osteolysis (Gorham disease; phantom bone disease):
1. Etiology: unknown, perhaps from vascular proliferation in marrow spaces (hemangiomatosis of bone), many cases have traumatic episode to start
2. GAL: none; young adults; mandible, pelvis, humerus, clavicle
3. Clinical: Bone starts to “dissolve”, showing poorly demarcated radiolucencies around and between the teeth, continues until much or all of the mandible and maxilla are gone; painless
4. Micro: Immature bone with osteoclastic and osteoblastic activity, with fibrosis of marrow spaces often containing many dilated capillaries
5. Treat: None is effective; surgical curettage is usually tried
Idiopathic osteosclerosis (bone scar; enostosis; bone island):
1. Etiology: by definition, unknown
2. GAL: none; 5-20 years of age; mandible, especially first molar and premolar region
3. Clinical: Irregular, relatively well defined and uniform radiopacity without capsule slowly enlarges between or at apex of teeth; asymptomatic; no cortical expansion; growth stops with adulthood
4. Micro: Dense lamellar bone with fibrous tissue in small spaces
5. Treat: none required unless secondarily infected, then conservative surgical removal
Paget’s disease of bone (osteitis deformans):
1. Etiology: abnormal, enhanced resorption and deposition of bone, possibly from a slow virus, such as paramyxovirus (detected in osteoclasts); 1/100 persons over 45 years of age, but most disease is subclinical
2. GAL: men; late middle age and older; maxilla and skull
3. Clinical: irregular radiolucent/radiopaque regions become more radiopaque over time (cotton wool appearance); early stage is radiolucent (osteoporosis circumscripta); jaws involved in 17%; may get anemia and bleeding (no hematopoietic tissue or platelets), deafness and visual loss (pinched nerves as they traverse foramina in skull base); Lincoln’s sign (black beard) with technetium bone scan (scintigraphy) when mandible is involved; enlargement of maxilla, small sinuses; bowed legs; elevated alkaline phosphatase (25%+ above normal); may be bone pain
4. Micro: classic appearance of Chinese character (mosaic; jig-saw) bone with immature trabecula and abundant osteoblastic but lesser osteoclastic activity, with fibrous background stroma; many reversal or cement lines in the bone
5. Treat: seldom causes death; parathyroid hormone antagonists (calcitonin, bisphosphonates), aspirin for pain; may do skull base surgery to relieve nerves; new dentures or bridgework may be required as maxilla expands. Up to 13% risk of osteosarcoma or giant cell tumor, the former seldom in jaws, the latter often in jaws.
Langerhans cell histiocytosis (Langerhans cell disease; histiocytosis X):
1. Etiology: unknown, proliferation of Langerhans cells (dendritic mononuclear cells normally found in epidermis, mucosa, lymph nodes, bone marrow, which process antigens to T cells)
2. GAL: none; first 2 decades of life; posterior mandible
3. Clinical: 3 basic types:
– Acute disseminated histiocytosis (Letterer-Siwe disease): severe visceral involvement
and dermal involvement, with death in the first two years of life
– Chronic disseminated histiocytosis (Hand-Schüller-Christian disease): bone, viscera and
cutaneous involvement; bone usually shows well demarcated radiolucency with no sclerotic rimming (punched our radiolucency); perforation rather than expansion of cortex; may have superficial alveolar destruction mimicking periodontitis; teeth become loose and exfoliate or appear to be floating in air radiographically; skull radiolucencies are frequent
– Eosinophilic granuloma: single alveolar punched out radiolucency or periodontitis-like
alveolar destruction; asymptomatic
4. Micro: eosinophils, macrophages, lymphocytes, multinucleated giant cells
5. Treat: curettage; earlier the onset, worst the prognosis; may be fatal
Central giant cell granuloma (giant cell lesion):
1. Etiology: unknown, but not thought to be neoplastic...perhaps “reparative”?
2. GAL; females; before 30 years of age; mandible, especially anterior
3. Clinical: two variants: the nonaggressive and more common type, and the aggressive lesion. Well defined radiolucency, usually with thin sclerotic rim and scalloped borders; may expand cortex and push teeth; may be multilocular or unilocular; usually <1 cm but may be up to 10 cm diameter. Rarely: may be painful or tender; may produce paresthesia, may perforate cortex.
4. Micro: multinucleated osteoclast-like cells in cellular stroma of spindled and oval mesenchymal cells with nuclei similar to those of the giant cells; extravasated erythrocytes; hemosiderin deposits (old hemorrhage); reactive new bone formation near periphery; not encapsulated but is well demarcated
5. Treat: surgical curettage; some respond to corticosteroid injections, some to calcitonin or interferon alfa-2a; up to 10-20% recur.
6. Special: the giant cell tumor of long bones is quite different and much more aggressive, often with a malignant biological behavior. The brown tumor of hyperparathyroidism looks exactly like it radiographically and microscopically (think of this if multiple or aggressive).
Cherubism (familial fibrous dysplasia):
1. Etiology: developmental anomalies; AD inheritance, defective gene on chromosome 16
2. GAL: none; first and second decades of life; posterior jaws, usually bilateral, often all four quadrants
3. Clinical: Greatly expansile radiolucencies, usually multilocular, begin prior to 5 years of age, enlarging until puberty, after which they usually stabilize and slowly regress. Face appears greatly enlarged, with “eyes toward heaven” because of pressure on infraorbital bone. Painless; tooth buds often pushed out of position; wide alveolus (speech problem?). Rarely: ribs and humerus involved. May have multiple multinucleated giant cell granulomas.
4. Micro: like giant cell granuloma, although often more loose tissue; eosinophilic cuffing around small vessels; old lesions: densely fibrous, fewer giant cells
5. Treat: none, unless pathologic fracture; usually facial features are normal by 25-40 years of age; surgical curettage can be performed; irradiation works, but risk of future sarcomas, so not done
Simple bone cyst (traumatic bone cyst; solitary bone cyst; idiopathic bone cavity):
1. Etiology: unknown, probably chronic ischemic bone disease
2. GAL: males; 10-25 years of age; posterior mandible
3. Clinical: poorly-demarcated to well-demarcated radiolucency, often with scalloped borders and often scalloped between tooth roots (teeth remain viable); 20% with expanded cortex; rarely: tender or painful; intramedullary void or cavitation
4. Micro: very little tissue available, usually with normal bone (maybe immature), fibrous tissue and a few lymphocytes
5. Treat: create cortical window, then curette walls of cavitation to stimulate fresh hemorrhage. Usually defect fills in with new bone in less than 6 months.
Aneurysmal bone cyst:
1. Etiology: unknown, but perhaps reactive response to trauma; some think it is an atypical central giant cell granuloma or similar to that lesion
2. GAL: none, teenagers and young adults; posterior mandible, shafts of long bones
3. Clinical: Multilocular, well-demarcated radiolucency, often with thin sclerotic rim; usually thins and expands cortex; often painful; may be compressible; may have paraesthesia; rarely: crepitus
4. Micro: thin fibrous trabecula with scattered multinucleated giant cells separate large blood-filled cavities; endothelial cells are not seen lining the cavities; erythrocyte extravasation may be seen in stroma; large areas of fibrous tissue may be seen; 20% are associated with another lesion, usually giant cell granuloma or benign fibro-osseous lesion.
5. Treat: curettage or enucleation, usually heals in 6-12 months; at least 8% recur
Fibrous dysplasia of bone:
1. Etiology: developmental anomaly from postzygotic mutation of GNAS 1 (guanine nucleotide-binding protein, alpha-stimulating activity polypeptide 1) gene
2. GAL: none; 7-20 years; posterior maxilla
3. Clinical: two basic types:
– Monostotic fibrous dysplasia: 85% of cases; jaws are among most common sites;
painless bony enlargement of diffuse alveolar or other maxillofacial area; growth is slow;
teethbecome separated but remain viable; ground-glass radiopacity, or irregular opacities,
ormixed radiolucent-radiopaque regions; poorly demarcated from surrounding normal
one; cortical expansion and thinning; lamina dura may be hard to see; PDL may be thin
– Craniofacial fibrous dysplasia: adjacent maxillary bones are involved (only)
–Polyostotic fibrous dysplasia (Jaffe-Lichtenstein syndrome; McCune-Albright
syndrome): relatively uncommon; may involve most of skeleton; café au lait spots;
sexualprecocity, hyperthyroidism, pituitary adenoma; hockey stick deformity of hip;
if only café au lait spots = Jaffe-Lichtenstein syndrome.
4. Micro: irregular immature bony trabecula in a fibrous background stroma, with no osteoblasts and no osteoclasts; no capsule; jaw lesions become more ossified with time
5. Treat: surgical recontouring; usually “burns out” with adulthood; may require multiple recontouring procedures during teen years.
6. Similar lesion: segmental odontomaxillary dysplasia: single maxillary quadrant shows radiopaque pattern of vertical stripes
Cemento-osseous dysplasia:
1. Etiology: developmental anomaly; may be familial
2. GAL: Female; young adults and early middle-aged; mandible; some lesions have racial predilection
3. Clinical: three basic groups:
– Focal cemento-osseous dysplasia: single site involved; 90% females; mean age 38 years;
more frequent in whites than blacks; posterior mandible; asymptomatic mixed
radiolucent/opaque areas less than 1.5 cm., becoming more sclerotic over time;
moderately well demarcated; nonexpansile
–Periapical cemento-osseous dysplasia (periapical cemental dysplasia): anterior mandible,
at apex of viable teeth; 14:1 female;male ratio; 70% in blacks; 30-50 years old;
asymptomatic; nonexpansile; lesions are similar to focal variant in appearance and
behavior
– Florid cemento-osseous dysplasia: multiple quadrants involved, usually mandible, usually periapical locations; lesions are larger than focal or periapical variants, and can expand cortex and produce tenderness or pain; may become exposed to surface (calcified material is rather avascular)
4. Micro: globular masses of dark calcified material (osseous or cementoid or both) with minimal cellularity, in a background stroma of immature fibrous tissue; encapsulated; may have one or more traumatic bone cysts
5. Treat: none required unless symptomatic, then conservative surgical curettage; try to prevent dental infections, since lesion is rather avascular
Familial gigantiform cementomas:
1. Etiology: unknown, but appears to be an adult onset “developmental” anomaly; AD inheritance
2. GAL: none; first and second decades; posterior mandible; racial predilection for whites
3. Clinical: Multiple, well demarcated, expansile, mixed radiolucent/radiopaque intraosseous lesions can become very large; may affect all four quadrants; impaction of teeth; facial deformity
4. Micro: same as for cemento-osseous dysplasia
5. Treat: continues to enlarge until fifth decade; once lesions are predominantly radiopaque surgical resection and recontouring can be done, may have to be repeated
Central ossifying fibroma (central cementifying/ossifying fibroma):
1. Etiology: benign neoplasm
2. GAL: none; young adults and early middle-age; mandibular molar and premolar region
3. Clinical: well demarcated unilocular radiolucency, sometimes with thin sclerotic rim; can be expansile and can become very large; asymptomatic; older lesions show irregular radiopacities in the radiolucency; can push roots aside
4. Micro: islands and irregular trabecula of immature bone in a background of immature fibrous tissue; often areas with dark cementoid calcified globules
5. Treat: Conservative surgical removal or curettage
6. Special variant: juvenile ossifying fibroma (juvenile aggressive ossifying fibroma): more rapid growth, larger growth capacity, high recurrence rate, younger patient (first 2 decades of life); two microscopic types: trabecular and psammomatoid
Osteoma:
1. Etiology: benign neoplasm; rare
2. GAL: none; teens and young adults; mandible, only found in H&N bones
3. Clinical: asymptomatic bony mass of cortex with normal overlying mucosa; radiopaque, maybe lobulated; may project into sinus; may be completely intramedullary
4. Micro: dense lamellar bone (compact osteoma) with small fibrous tissue-filled spaces, occasional marrow; some masses have normal marrow space (cancellous osteoma)
5. Treat: conservative surgical removal, otherwise will slowly continue to enlarge
Gardner syndrome:
1. Etiology: AD inheritance (mutation on chromosome 5); prevalence rate: 1/8,000 births
2. GAL: none, second and third decades; mandible
3. Clinical: multiple osteomas (usually compact type) of maxillofacial bones; adenomatous intestinal polyposis, with at least 50% risk of adenocarcinoma transformation; sometimes odontomas; supernumerary teeth; impacted teeth; epidermoid cysts of skin; desmoid tumors of skin; rarely: thyroid carcinoma; pigmented lesions of ocular fundus
4. Micro: osteomas are as above, intestinal polyps are adenomatous in nature
5. Treat: osteomas can be conservatively removed via surgery; polyps are monitored carefully by internist and removed when too large or too numerous (prophylactic colectomy is frequent); skin cysts and fibrous tumors can be conservatively removed as needed
Osteoblastoma:
1. Etiology: benign neoplasm of osteoblasts
2. GAL: slight male; 10-30 years of age; posterior mandible
3. Clinical: 2-4 cm well demarcated radiolucency with sclerotic rimming of periphery; often patchy irregular radiopacities; may expand cortex; painless
4. Micro: irregular trabecula of immature bone with abundant osteoblastic rimming and with numerous osteoblasts seen in background fibrous stroma
5. Treat: conservative surgical excision or curettage; small recurrence rate
6. Special variant: aggressive osteoblastoma: has atypical cells and is very cellular, occurs in older persons, often painful, may become very large
7. Similar lesion: osteoid osteoma: identical histology but center has plexus of nerves and there is usually a thick sclerotic rimming around lesion; very painful but pain disappears with aspirin or other prostaglandin inhibitors
Chondroma:
1. Etiology: benign neoplasm of hyaline cartilage and chondrocytes
2. GAL: none; third and fourth decades; anterior maxilla, condyle, usually hands and feet
3. Clinical: asymptomatic cortical expansion, slow enlargement; well demarcated radiolucency with scattered globular radiopacities.
4. Micro: mature hyaline cartilage, encapsulated, small chondrocytes in well-formed lacunae
5. Treat: conservative surgical excision or curettage; low recurrence outside facial bones, but in facial bones recurrence should be suspected as being a low-grade chondrosarcoma (which can look microscopically very similar)