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.

• Blood: Aneurysmal bone cyst, Vascular lesion, Vessel puncture.

• Air: Traumatic bony cyst (Simple Bone Cyst/Hemorrhagic Bone Cyst), Maxillary sinus.

• Chocolate Colored Fluid: Warthin's Tumor (salivary gland cyst).

• Stevens-Johnson Syndrome (SJS):

  • Characterized by ulcers with hemorrhagic crusts.

  • Typically has an acute onset following drug exposure (mainly sulfa group drugs).

• Biopsy for Vesiculobullous Pathology: Should be taken from the margin of the vesicle/bulla, including a significant amount of normal-appearing mucosa, to capture the pathological changes and adjacent healthy tissue for comparison.

• Linea Alba: A white, bilateral line on the buccal mucosa associated with pressure, frictional irritation, or sucking trauma from the facial surface of teeth.

• Morsicatio Buccarum: Chronic irritation seen on the buccal mucosa as a result of suction and glassblowers (chewing habits).

• Riga-Fede Disease: Sublingual ulcerations in infants resulting from chronic mucosal trauma from adjacent primary teeth (often natal/neonatal teeth).

• Epithelial Plaques (localized thickenings): Found in:

  • Lateral Periodontal Cyst

  • Botryoid Odontogenic Cyst

  • Gingival Cyst of Adults

  • Glandular Odontogenic Cyst

• 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)

• Bull Neck: Seen in Diphtheria and Ludwig's Angina.

• Bull's Eye Lesion / Target Lesions: Characteristic of Stevens-Johnson Syndrome and Erythema Multiforme.

• Bull's Teeth: Refers to Taurodontism.

• Circus Rubber Man: Clinical appearance associated with Ehlers-Danlos Syndrome (due to hypermobility and skin elasticity).

• Claw Hands: A physical deformity seen in advanced Scleroderma.

• Coup de Sabre: A linear depression or groove resembling a "saber cut" seen in Facial Hemiatrophy (Parry-Romberg Syndrome) and localized Scleroderma (linear scleroderma).

• CREST Syndrome: A limited form of Scleroderma, characterized by:

  • Calcinosis

  • Raynaud's phenomenon

  • Esophageal dysfunction

  • Sclerodactyly

  • Telangiectasias

• Crowe's Sign: Axillary or inguinal freckling seen in Neurofibromatosis Type 1.

• Frog Facies: A characteristic facial appearance seen in Crouzon Syndrome (due to midfacial hypoplasia and exophthalmos).

• Gorlin Sign: The ability to touch the tip of the nose with the tongue, seen in Ehlers-Danlos Syndrome (due to increased joint laxity).

• Hockey Stick Deformity of Femur and Shepherd's Crook Sign: Radiographic findings typically associated with Fibrous Dysplasia.

• Parrot's Beak Nose: A nasal deformity seen in Crouzon Syndrome.

• Red Strawberry Tongue and Pastia's Lines: Clinical signs characteristic of Scarlet Fever.

• Rodent Facies: A facial appearance often associated with Thalassemia.

• Simian Stance: A stooped posture, reminiscent of an ape, seen in Paget's Disease of Bone.

• Snail Track Ulcers: Serpiginous, grayish-white lesions on mucous membranes, characteristic of Syphilis (mucous patches in secondary syphilis).

• Socks Feet and Mitten Hands: Refers to syndactyly (fusion of digits) appearing like a sock or mitten, seen in Apert's Syndrome.

• Parrot Beak Shaped Nails: A nail deformity (onychogryphosis) seen in Congenital Syphilis.