Viral Infections

Herpes Simplex Virus (HSV-1)

• Dormancy Sites: Trigeminal > Nodose (Vagus) > Dorsal Root > Brain
• Inclusions: Lipschutz bodies (intranuclear)
• Herpetic Whitlow: Finger lesions in dentists
• Location Difference:
  • Herpangina: Posterior palate
  • Herpes: Anterior palate

Herpes Zoster

• Key Feature: Lesions do not cross midline
• Ramsay Hunt Syndrome: Zoster of geniculate ganglion → facial paralysis

Measles

• Koplik's Spots: Disappear after skin rash onset

Rubella

• First Trimester: Blindness, deafness, cardiovascular defects

Mumps

• Complications: Orchitis, oophoritis (sterility), pancreatitis, meningoencephalitis

Gemination

• Attempted division of a single tooth germ before calcification.

• Results in two crowns (complete/incomplete) with one root and canal.

• Tooth count remains normal.

• Difficult to differentiate from fusion with a supernumerary tooth.

 Twinning

• Complete division of a single tooth germ.

• Results in one normal + one supernumerary tooth.

• Tooth count is more than normal.

Fusion

• Union of two separate tooth germs.

• If before calcification → single large tooth.

• If after calcification → roots fused, crowns may be separate.

• More common in deciduous teeth.

Concrescence

• Union by cementum only.

• Occurs after root formation.

• Common in maxillary molars.

Chronic Osteomyelitis

• As soon as pus drains intra or extraorally, condition ceases to spread and chronic phase commences.
• Infection is localized but persistent as bacteria are able to grow in dead bone inaccessible to body’s defenses.

Clinical features

• Primary – insidious in onset , slight pain , gradual increase in jaw size.
• Secondary - Pain is deep pain and intermittent, temperature fluctuations , pyrexia , cellulitis eventually leading to abscess
• New bone formation leads to thickening causing facial asymmetry.
• Thickened or “wooden” character of bone in cr sec osteomyelitis.
• Eventually cures itself as the last sequestra is discharged.

Radiographic Features

• Trabeculae in the involved area become thin or appear fuzzy & then lose their continuity.
• After some time “moth eaten” appearance is seen
• Sequestra appear denser on radiographs.
• Where the subperiosteal new bone formation , the new bone is superimposed upon that of jaw, “fingerprint” or “orange peel” appearance is seen
• Cloacae seen as dark shadows passing through opacity.

Histologic features

• Areas of acute and subacute inflammation in the cancellous spaces of the necrotic bone.
• Foci of acute inflammation
• Active osteoclastic resorption of bone noted in peripheral portions

Chronic Subperiosteal Osteomyelitis

• Cortical plate deprived of its blood supply undergoes necrosis, underlying medullary bone  is slightly affected.
• Multiple small sequestra form, eventually discharged through sinuses with pus.
• Following extrusion of sequestra, healing occurs.
• Spontaneous drainage poor in submassetric area.
• Much of  body of mandible is lost due to poor central blood supply of the region.

D/D

• Paget’s disease – particularly wen periosteal bone is involved
• Fibrous dysplasia
• Osteosarcoma

Chronic sclerosing osteomyelitis

– focal

- diffuse

Focal Sclerosing Osteomyelitis

Clinical features

• Most commonly in children and young adults, rarely in older individuals.
• Tooth most commonly involved is the mandibular third molar presenting with a large carious lesion.
• No signs or symptoms other than mild pain associated with infected pulp.

Radiographic features

• Entire root outline always visible with intact lamina dura.
• Periodontal ligament space widened.
• Border smooth & distinct appearing to blend into surrounding bone

D/D for focal sclerosing osteomyelitis

• Local bone sclerosis
• Sclerosing cementoma
• Gigantiform cementoma

Treatment & prognosis

• Affected tooth may be treated endodontically or extracted.
• Sclerotic bone  not attached to tooth and remains behind after tooth is removed.
• This dense area may not get remodeled.
• Recognizable on bone years later and is referred as bone scar.

Diffuse Sclerosing Osteomyelitis

• May occur at any age, most common in older persons, esp in edentulous mandibles
• vague pain, unpleasant taste.
• Many times spontaneous formation of fistula seen opening onto mucosal surface to establish drainage
• Slowly progressive, not particularly dangerous since it is non destructive & seldom produces complications

Radiographic features

• Diffuse patchy, sclerosis of bone – “cotton wool” appearance
• Radiopacity may be extensive and bilateral.
• Due to diffuse nature, border between sclerosis & normal bone is often indistinct

D/D for DIFFUSE sclerosing osteomyelitis

FLORID OSSEOUS DYSPLASIA

SCLEROTIC CEMENTAL MASSES

TRUE CHR DIFFUSE SCLEROSING OSTEOMYELITIS

FIBROUS DYSPLASIA

Treatment & Prognosis

• Resolution of adjacent foci of chronic infection often leads to improvement.
• Usually too extensive to be removed surgically,
• Acute episodes treated with antibiotics.

• Hyperplastic Candidiasis: The only form of candidiasis that is non-scrapable. Often appears as admixed white and red areas, known as speckled leukoplakia or erythroleukoplakia.

• Median Rhomboid Glossitis: Etiology is controversial (developmental vs. fungal); if forced to choose, developmental.

• Gilchrist's Disease: Another name for North American Blastomycosis.

• Mucormycosis: More common in diabetic patients. Has a strong propensity to invade blood vessels.

• Dentigerous Cyst (Follicular Cyst):

  • Most common Developmental Odontogenic Cyst.

  • Always associated with the crown of an unerupted/impacted tooth.

  • Derived from Reduced Enamel Epithelium (REE).

  • Differential diagnosis: Eruption cyst, Paradental cyst (also from REE).

• Nasopalatine Duct Cyst (Incisive Canal Cyst/Median Anterior Maxillary Cyst - MAMC):

  • Most common Developmental Non-odontogenic Cyst.

  • Located in the midline of the anterior maxilla.

• Radicular Cyst (Periapical Cyst):

  • Most common Odontogenic Cyst overall.

  • Always associated with a non-vital tooth.

  • Inflammatory origin.

• Odontogenic Keratocyst (OKC) / Keratocystic Odontogenic Tumor (KCOT):

  • Primordial Cyst: An OKC found in place of a missing tooth.

  • Protein Content: Less than 4 gm/dL.

  • Aggressive Behavior: High mitotic activity, high PCNA index, and Ki67 activity.

  • Derived from Rests of Serres (remnants of dental lamina).

• Mucocele:

  • Common term for:

    • Mucous Extravasation Phenomenon (Pseudocyst): No epithelial lining.

    • Mucous Retention Cyst (True Cyst): Has an epithelial lining.

Infantile Osteomyelitis

• Osteomyelitis Maxillaries Neonatarum, Maxillitis of infancy
• Osteomyelitis in the jaws of new born infants occurs almost exclusively in maxilla.

Etiology

• Trauma – through break in mucosa cause during delivery.
• Infection of maxillary sinus
• Paunz & Ramon et al  believe that disease caused through infection from the nose.
• Hematogenous spread through streptococci & pneumococci

Clinical features

• Fever, anorexia & intestinal disturbances.
• swelling or redness below the inner canthus of the eye in lacrimal region.
• Followed by marked edema of the eyelids on the affected side.
• Next, alveolus & palate in region of first deciduous molar become swollen.
• Pus discharge from affected sites

D/D for Infantile Osteomyelitis

• Dacrocystitis neonatarum
• Orbital cellulitis
• Ophthalmia neonatarum
• Infantile cortical hyperostosis

TREATMENT

• Intravenous antibiotics, preferably penicillin.
• Culture & sensitivity testing
• Incision & drainage of fluctuant areas
• Sequestrectomy
• Supportive therapy