Introduction

• Cause: abscess/cellulitis, neoplasia, cysts and mucocele, extraocular polymyositis, masticatory muscle myositis, hemorrhage, craniomandibular osteopathy, vascular anomalies.
• Signs: exophthalmos, strabismus, globe indentation, nictitans protrusion, difficulty or discomfort on opening mouth, red eye, restriction of globe retropulsion, unilateral nasal discharge/blockage.
• Diagnosis: ultrasonography, advanced imaging (CT/MRI), fine needle aspiration biopsy.
• Treatment: depends on cause. Drainage and antibiotics and anti-inflammatories for abscess, surgery/chemotherapy/radiation therapy for neoplasia, immunosuppressive agents for extraocular polymyositis and masticatory muscle myositis.
• Prognosis: good for abscess/cellulitis, cysts and mucoceles, guarded-fair for extraocular polymyositis and masticatory muscle myositis, usually poor for neoplasia.

Pathogenesis

Etiology

• Abscess/cellulitis.
• Neoplasia.
• Cysts/mucoceles.
• Extraocular polymyositis.
• Masticatory myositis.
• Vascular anomalies.
• Craniomandibular osteopathy.

Pathophysiology

• Abscess/cellulitis:
  • Hematogenous dissemination.
  • Penetrating injury.
  • Foreign body.
  • Tooth root abscess.
• Neoplasia:
  • Primary - arising from any orbital tissue.
  • Secondary - extension from neighbouring tissue or metastasis.
  • Usually malignant.
• Myositis:
  • Immune-mediated inflammatory myopathy.
• Cysts:
  • Dermoid:
    • Congenital.
  • Salivary retention cysts:
    • Result from inflammation of oral mucosa and obstruction of salivary flow.
• Mucoceles:
  • Sialoceles:
    • Usually result from trauma.
• Vascular anomalies:
  • Congenital or acquired.
• Craniomandibular osteopathy:
  • Inherited.
• Hemorrhage:
  • Trauma.

Timecourse

• Varies depending on cause.

Diagnosis

Treatment

Outcomes