📖 Oral Pathology
Infective osteomyelitis
Oral PathologyInfective osteomyelitis
- Tuberculous osteomyelitis
- Syphilitic osteomyelitis
- Actinomycotic osteomyelitis
Tuberculous osteomyelitis
- Non healing sinus tract formation
- Age group affected is around 15 – 40 years.
- Commonly seen in phalanges and dorsal and lumbar vertebrae.
- Usually occurs secondary to tuberculosis of lungs.
- Cases have been reported where mandibular lesions were not associated with pulmonary disease.
- Another common entrance is through a carious tooth via open pulp.
- Usually affects long bones and rare in jaws.
- Results when blood borne bacilli lodge in cancellous bone. Usually in ramus , body of mandible. may mimic parotid swelling or submassetric abscess.
Syphilitic osteomyelitis
- Difficult to distinguish syphilitic osteomyelitis of the jaws from pyogenic osteomyelitis on clinical & radiographic examination.
- Main features are progressive course & failure to improve with usual treatment for pyogenic osteomyelitis.
- Massive sequestration may occur resulting in pathologic fracture.
- If unchecked, eventually causes perforation of the cortex.
Actinomycotic Osteomyelitis
- The organisms thrive in the oral cavity, especially tissues adjacent to mandible.
- May enter the bone through a fresh wound, carious tooth or a periodontal pocket at the gingival margin of erupting tooth.
- Soft or firm tissue masses on skin, which have purplish, dark red, oily areas with occasional zones of fluctuation.
- Spontaneous drainage of serous fluid containing granular material.
- Regional lymph nodes occasionally enlarged.
- Mimics parotitis / parotid tumors
Osteoradionecrosis
Oral PathologyOsteoradionecrosis
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.
Non-epithelial cysts
Oral PathologyNon-epithelial cysts (not true cysts)
Solitary bone cyst
Radiology
The solitary bone cyst appears as a well-defined but non-corticated radiolucency. Typically, it has little effect
on adjacent structures and 'arches' up between the roots of teeth .
The inferior dental canal may not be displaced, but the cortical margins of the canal may be lost where it overlies the lesion. Expansion is rare.
Pathology
The cyst is lined by fibrovascular tissue that often includes haemosiderin and multinucleate giant cells.
Aneurysmal bone cyst
Radiology
The aneurysmal bone cyst typically presents as a fairly well-defined radiolucency. Sometimes it has a multilocular appearance because of the occurrence of internal bony septa and opacification. Marked expansion is a feature.
Pathology
The predominant feature of an aneurysmal bone cyst is the presence of blood-filled spaces of variable size lying in a stroma rich in fibroblasts, multinucleate giant cells and haemosiderin. Deposits of osteoid are also seen
Classification of cysts of the orofacial region
Oral PathologyEpithelial cysts
Developmental odontogenic cysts
Odontogenic keratocyst
Dentigerous cyst (follicular cyst)
Eruption cyst
Lateral periodontal cyst
Gingival cyst of adults
Glandular odontogenic cyst (sialo-odontogenic)
Inflammatory odontogenic cysts
Radicular cyst (apical and lateral)
Residual cyst
Paradental cyst
Non-odontogenic cysts
Nasopalatine cyst
Nasolabial cyst
Non-epithelial cysts (not true cysts)
Solitary bone cyst
Aneurysmal bone cyst