Garre’s Osteomyelitis (Chronic Osteomyelitis with Proliferative Perosteitis)

• Chronic Non Suppurative Sclerosing Osteitis/ Periostitis Ossificans.
• Non suppurative productive disease characterized by a hard swelling.
• Occurs due to low grade infection and irritation
• The infectious agent localizes in or beneath the periosteal covering of the cortex & spreads only slightly into the interior of the bone.
• Occurs primarily in young persons who possess great osteogenic activity of the periosteum.

Clinical Features

• Uncommonly encountered, described in tibia and in the head and neck region, in the mandible.
• Typically involves the posterior mandible & is usually unilateral.
• Patients present with an asymptomatic bony, hard swelling with normal appearing overlying skin and mucosa.
• On occasion slight tenderness may be noted
• pain is most constant feature
• The increase in the mass of bone may be due to mild toxic stimulation of periosteal osteoblasts by attenuated infection.

Radiographic features

• Laminations vary from 1 – 12 in number, radiolucent separations often are present between new bone and original cortex. (“onion skin appearance”)
• Trabeculae parallel to laminations may also be present.

Histologic Features

• Reactive new bone.
• Parallel rows of highly cellular & reactive woven bone in which the individual trabeculae are oriented perpendicular to surface.
• Osteoblasts predominate in this area.

D/D for Garre’s Osteomyelitis

• Ewing's sarcoma
• Caffey’s disease
• Fibrous dysplasia
• Osteosarcoma

Treatment

• Removal of the offending cause.
• Once inflammation resolves, layers of the bone consolidate in 6 – 12 months, as the overlying muscle helps to remodel.
• If no focus of infection evident, biopsy recommended.

• Café au Lait Spots:

  • "Coast of California": Associated with Neurofibromatosis (Type 1).

  • "Coast of Maine": Associated with Fibrous Dysplasia.

• Carpet Tack Lesions: Characteristic of Discoid Lupus Erythematosus.

• Cerebriform Tongue: Seen in Pemphigus Vegetans.

• Charcot's Triad: Seen in Multiple Sclerosis, characterized by:

  • Intention tremor

  • Nystagmus

  • Dysarthria

• Chipmunk Facies: Seen in Thalassemia.

• Chvostek's Sign: Indicative of Hypoparathyroidism (facial muscle twitching upon tapping the facial nerve).

• Buffalo Hump: A characteristic clinical sign of Cushing's Syndrome (fat pad on the upper back).

• Most Common Benign Odontogenic Tumor: Odontoma (Ameloblastoma is second).

• Adenoid Cystic Carcinoma vs. Adenomatoid Odontogenic Tumor (AOT):

  • Adenoid Cystic Carcinoma: Salivary gland malignancy.

  • Adenomatoid Odontogenic Tumor (AOT): Benign odontogenic tumor. Do not confuse them.

• Liesegang Rings: Can be seen in CEOT/Pindborg's Tumor (primarily) and AOT (rarely).

• Amyloid-like Deposits: Characteristic feature of CEOT (Calcifying Epithelial Odontogenic Tumor).

• Duct-like Structures: Seen in AOT (Adenomatoid Odontogenic Tumor).

• Granular Cell Ameloblastoma: Granules are lysosomal aggregates.

Osteoradionecrosis

Clinical features

A reduction in vascularity, secondary to endarteritis obliterans, and damage to osteocytes as a consequence of ionising

Radiotherapy can result in radiation-associated osteomyelitis or Osteoradionecrosis. The mandible is much more  commonly affected than the maxilla, because it is less vascular. Pain may be severe and there may be pyrexia. The overlying oral mucosa often appears pale because of radiation damage. Osteoradionecrosis in the jaws arises most often following radiotherapy for squamous cell carcinoma.
 

Scar tissue will also be present at the tumour site, often in close relation to the necrotic bone.

Radiology
 

Osteoradionecrosis appears as rarefying osteitis within which islands of opacity (sequestra) are seen. Pathological

fracture may be visible in the mandible.

Pathology
The affected bone shows features similar to those of chronic osteomyelitis. Grossly, the bone may be cavitated

And discoloured, with formation of sequestra.
Acute inflammatory infiltrate may be present on a background of chronic inflammation, characterized by formation

Of granulation tissue around the non-vital trabeculae.

Blood vessels show areas of endothelial denudation and obliteration of their lumina by fibrosis.

Small telangiectatic vessels lacking precapillary sphincters may be present.

Fibroblasts in the irradiated tissues lose the capacity to divide and often become binucleated and enlarged.

Management

Prevention of Osteoradionecrosis is vital. Patients who  require radiotherapy for the management of head and

neck malignancy should ideally have teeth of doubtful prognosis extracted at least 6 weeks prior to treatment.

The dose of radiation,
The area of the mandible irradiated and
the surgical trauma involved in the dental extractions.
Surgical management of Osteoradionecrosis is similar to osteomyelitis.

• Pemphigus → Granular IgG intercellular
• Lichen Planus → Linear anti-fibrinogen at BM, with lamina propria extensions
• Cicatricial Pemphigoid → Patchy linear IgG/C3 at BM
• Bullous Pemphigoid → Patchy linear IgG at BMZ
• Erythema Multiforme → Patchy linear fluorescence
• Discoid Lupus (Lesional mucosa) → Speckled pattern (IgG, IgM, IgA, C3, fibrinogen)

Regional Odontodysplasia

• Key Feature: Widened pre-dentin layer
• Histology: Large areas of interglobular dentin

Supernumerary Roots

• Most Common: Mandibular canines and premolars

Congenitally Missing Teeth

Permanent Teeth (Descending Order):

1. Third molar
2. Mandibular 2nd premolar
3. Maxillary lateral incisor
4. Maxillary 2nd premolar

Deciduous Teeth: Maxillary and mandibular lateral incisors