NEET MDS Lessons
Oral Pathology
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-
- Acute intramedullary
- 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.
Smoker's Palate & Melanosis
- Status: NOT premalignant
- Exception: Reverse smoking palatal changes ARE premalignant
Oral Submucous Fibrosis (OSMF)
Initial Stage:
- Vesicles may be present
- Dilated capillaries
Advanced Stage:
- Compressed capillaries due to fibrosis
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.
- Mosaic / Cotton Wool Bone → Paget’s Disease
- Orange Peel / Ground Glass → Monostotic Fibrous Dysplasia
- Salt & Pepper Bone → Thalassemia
- Phantom Bone / Massive Osteolysis → Bone disappearance
- Drill / Rider’s / Exercise Bone → Myositis Ossificans
- Brittle Bone → Osteogenesis Imperfecta
- Wormian Bones → Cleidocranial Dysplasia
- Coarse Woven Bone → Fibrous Dysplasia
|
Condition |
Key Features |
|
Paget's Disease |
- Denture tightening (arch expansion) |
|
Osteopetrosis |
- Rugger jersey spine |
|
Fibrous Dysplasia |
- Leontiasis ossea |
|
Cemento-Ossifying Fibroma |
- Leontiasis ossea |
|
Hyperparathyroidism |
- Ground glass appearance (Brown tumor) |
|
Cherubism |
- Giant cells + vascular stroma + hemosiderin |
|
Central Giant Cell Granuloma |
- Giant cells + vascular stroma + hemosiderin |
|
Juvenile Ossifying Fibroma |
- More aggressive than COF |
Mnemonics Flashcards
|
Mnemonic |
Meaning |
|
Paget's Patients Prefer Tight Dentures |
Paget's → Denture tightening due to arch expansion |
|
Fibrous Faces Feel Funny |
Fibrous dysplasia → Leontiasis ossea, Chinese script, Ground glass, Hockey stick femur |
|
Giant Cells Have Three Homes |
Seen in: Hyperparathyroidism, Cherubism, CGCG |
| Species | Role |
|---|---|
| Streptococcus mutans | Initiates caries; highly acidogenic/aciduric |
| Streptococcus sobrinus | Similar to S. mutans, less adhesive |
| Lactobacillus spp. | Progression in dentin; acid-loving |
| Actinomyces naeslundii/viscosus | Linked with root surface caries |
| Veillonella spp. | Lactate metabolizers in advanced lesions |
| Scardovia wiggsiae | Emerging cause in early childhood caries |
| Propionibacterium, Bifidobacterium, Rothia | Found in deep dentinal lesions |
-
Solitary Bone Cyst (Traumatic Bone Cyst): Usually situated above the inferior dental canal.
-
Stafne's Bone Defect (Static Bone Cavity/Lingual Mandibular Bone Defect): Located below the inferior dental canal. (Note: Stafne's is a pseudocyst/developmental defect, not a true cyst).