General Features

• Caused by mutation in DSPP gene (dentin sialophosphoprotein).

• Teeth appear translucent or opalescent.

• Enamel fractures easily due to poor dentin support.

• Pulp chambers are obliterated or enlarged depending on type.

• Also called Hereditary Opalescent Dentin or Shell Teeth.

Type II DI

• Pulp chambers are normal but rapidly obliterate.

• Associated with progressive hearing loss.

Type III DI

• Pulp chambers are large and shell-like.

• Seen in Brandywine isolate population.

• SLE → IgG, IgM, IgA deposits at BMZ + superficial lamina propria
• Lichen Planus (Erosive/Atrophic) → Autoimmune T-cell; BMZ involvement
• Cicatricial Pemphigoid → Subepidermal blistering from anti-BMZ antibodies

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.

• 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).

• Actinomycosis (Sulfur Granules):

  • Yellow sulfur granules: Are actually bacterial colonies.

  • Histopathology: Colonies appear "cotton wool" shaped. (Note: "Cotton wool appearance" is seen radiographically in Paget's disease).

• Tuberculosis (TB):

  • Diagnosis (Gold Standard): Presence of acid-fast bacilli in sputum.

  • Staining Method: Ziehl-Neelsen staining method is used to identify acid-fast bacilli.

  • Scrofula: TB of cervical lymph nodes.

  • Lupus Vulgaris: TB of skin.

• Tongue & Gingival Appearance in Systemic Conditions:

  • Strawberry tongue and Raspberry tongue: Seen in stomatitis of Scarlet Fever.

  • Strawberry Gingivitis: Seen in Wegener's Granulomatosis.

Acute suppurative osteomyelitis

• Serious sequela of periapical infection.
• Leads to spread of pus through the medullary cavities of bone.
• Depending upon the main site of involvement of bone, can be of two types-

1. Acute intramedullary
2. Acute subperiosteal

Acute Intramedullary Osteomyelitis

CLINICAL FEATURES:

• Patient experiences dull , continuous pain , indurated swelling forms over the affected region of jaw involving the cheek , febrile.
• When mandible involved, loss of sensation occurs on lower lip on affected side due to involvement of inferior alveolar nerve.
• Teeth become loose later along with tender on percussion
• Pus discharge , trismus , foul smell , regional lymphadenopathy , weakness

RADIOGRAPHIC FEATURES

• Earliest radiographic change is that trabeculae in involved area are thin, of poor density & slightly blurred.
• Subsequently multiple radiolucencies appear which become apparent on radiograph.
• In some cases there is saucer shaped area of destruction with irregular margins.
• Loss of continuity of lamina dura, seen in more than one tooth.

HISTOLOGIC FEATURES:

• Dense infiltration of marrow by polymorphonuclear leukocytes.
• Bone trabeculae in involved site (sequestrum) are devoid of cells in the lacunae.
• separation of considerable portions of devitalized bone.

Acute Subperiosteal Osteomyelitis

CLINICAL FEATURES

• Pain , febrile condition , i/o and e/o swelling , parasthesia
• Bone involvement limited to localized areas of cortex.
• Pus ruptures rapidly through the overlying cortex, tracks along the surface of mandible under the periosteal sheath.
• Elevation of periosteum from cortex is followed eventually by minute cortical sequestration.