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.

• Epithelial Plaques (localized thickenings): Found in:

  • Lateral Periodontal Cyst

  • Botryoid Odontogenic Cyst

  • Gingival Cyst of Adults

  • Glandular Odontogenic Cyst

Osteomyelitis

Osteomyelitis is an extensive inflammation of a bone. It involves the cancellous portion, bone marrow, cortex, and periosteum

Conditions that alter HOST IMMUNITY

Leukemia, Severe anemia, Malnutrition, AIDS, IV- drug abuse, Chronic alcoholism, Febrile illnesses, Malignancy, Autoimmune disease, Diabetes mellitus, Arthritis, Agranulocytosis

Conditions that alter vascularity of bone

Osteoporosis, Paget’s disease, Fibrous dysplasia, Bone malignancy, Radiation, Virulence of the organisms

Certain organisms precipitate thrombi formation by virtue of their destructive lysosomal enzymes.

Organisms proliferate in enriched host medium while protected from host immunity.

Etiology

- Odontogenic infections
- Trauma
- Infections of oro facial region
- Infections derived from hematogenous route
- Compound fractures of the jaws.

PATHOGENESIS

DEV . OF INFECTION --> BACTERIAL INVASION -->  PUS FORMATION -->  SPREAD OF INFECTION --> INCREASED INTRAMEDULLARY PRESSURE , BLOOD FLOW , OSTEOCLASTIC ACTIVITY --> INFLAMMATORY RESPONSES --> INCREASED PERIOSTEAL PRESSURE --> PROCESS BECOMES CHRONIC GRANULATION TISSUE FORMATION --> LYSIS OF BONE --> SEQUESTRUM FORMATION

Classification

Classification based on clinical picture, radiology, and etiology

Suppurative osteomyelitis

I. Acute suppurative osteomyelitis

II. Chronic suppurative osteomyelitis

– Primary chronic suppurative osteomyelitis

– Secondary chronic suppurative osteomyelitis

III. Infantile osteomyelitis

Nonsuppurative osteomyelitis

I. Chronic sclerosing osteomyelitis

  – Focal sclerosing osteomyelitis

  – Diffuse sclerosing osteomyelitis

II. Garre's sclerosing osteomyelitis

III. Actinomycotic osteomyelitis

IV. Radiation osteomyelitis and necrosis

Benign Lymphoepithelial Lesion / Mikulicz Syndrome

• Chronic enlargement of lacrimal and salivary glands

• Associated with Sjogren’s syndrome

Sialosis / Sialadenosis

• Non-inflammatory, non-neoplastic enlargement of salivary glands

Sialadenitis

• Inflammatory disease of salivary glands

 Sialadenoma Papilliferum

• Papillomas of salivary gland excretory ducts

Atresia

• Congenital absence or occlusion of major salivary gland ducts

Sialorrhea

• Increased salivation

• Seen in conditions like Parkinson’s disease

 Sialolithiasis

• Salivary duct stones in glands or ducts

• Common in submandibular gland

 Sialodochitis

• Inflammation of salivary gland ducts

Nasopalatine cyst

Radiology

The nasopalatine cyst appears as a well-defined, round radiolucency in the midline of the anterior maxilla . Sometimes it appears to be 'heart-shaped' because of super-imposition of the anterior nasal spine.

Radiological assessment should include examination of the lamina dura of the central incisors (to exclude a radicular cyst) and assessment of size (the nasopalatine foramen may reach a width of as much as 10 mm).

Pathology

The cyst is lined by a layer of pseudostratified ciliated columnar epithelium and/or stratified squamous epithelium. The capsule of the cyst is fibrous and may include the incisive canal neurovascular bundle.

Nasolabial cyst

Radiology

'Bowing' inwards of the anterolateral margin of the nasal cavity has been recorded

Pathology

The nasolabial cyst is lined by non-ciliated pseudostratified columnar epithelium, which is often rich in mucous cells.

Leukoedema

• Diagnostic Feature: Lesions do not rub off; disappear when cheek is stretched

Heck's Disease (Focal Epithelial Hyperplasia)

• Appearance: Cobblestone mucosa
• Also Seen In: Pyostomatitis vegetans, Keratosis follicularis

Infectious Mononucleosis

• Nickname: Kissing disease
• Etiology: Epstein–Barr Virus (EBV)