4. Major Infections of mouth and face

Identify the specific causative agents for oral actinomycosis (Actinomyces israelii), tuberculosis (Mycobacterium tuberculosis), and syphilis (Treponema pallidum).
Describe the classic clinical presentation of oral actinomycosis as a chronic, suppurative swelling, often near the angle of the jaw, that may form a draining sinus.
Recognize the key histopathological features of tuberculosis, specifically the formation of granulomas with central caseous necrosis and the presence of multinucleated giant cells.
Differentiate the oral manifestations of primary, secondary, and tertiary syphilis, with a focus on recognizing the primary chancre.
Correlate specific microscopic findings to their respective diseases:
- ‘Sulphur granules’ with actinomycosis.
- A dense, perivascular lymphocytic infiltrate with syphilis.

Explain the concepts of viral latency and reactivation, particularly for the herpesvirus family, and identify immunosuppression as a key trigger.
Differentiate between the clinical signs of a primary HSV infection (e.g., widespread primary herpetic gingivostomatitis) and a recurrent infection (e.g., localized herpes labialis).
Identify hairy leukoplakia by its unique clinical appearance (white, non-removable, vertically corrugated lesions on the lateral tongue) and associate it with its causative agent (EBV) and common risk factors (e.g., HIV infection).
Distinguish between the common benign oral lesions caused by HPV based on their typical clinical morphology and location:
- Squamous papilloma (small, often on the soft palate).
- Verruca vulgaris (white, keratotic, on lips/gingiva).
- Heck disease (multiple papules on lips/tongue, common in children).
Recognize the strict unilateral distribution of painful vesicles and ulcers along a nerve path as the hallmark clinical sign of oral shingles (reactivated VZV).

List at least five key local and systemic predisposing factors for oral candidosis, such as xerostomia, denture use, broad-spectrum antibiotic use, and immune defects.
Differentiate between the major clinical forms of oral candidosis based on their appearance:
- Pseudomembranous (Thrush): Removable white plaques.
- Acute Atrophic: Red, raw, painful mucosa (e.g., “antibiotic sore mouth”).
- Chronic Hyperplastic: Non-removable white plaques (candidal leukoplakia).
- Angular Cheilitis: Inflammation at the lip commissures.
Describe the pathogenesis of angular cheilitis, linking it to the “3Ds” (Denture-wearing, Deficiency states, and Disorders like reduced vertical dimension).
Identify the characteristic microscopic features of a candidal infection, including the invasion of superficial epithelial layers by fungal hyphae and the presence of neutrophil microabscesses.

Connective Tissue disorders

To develop a basic knowledge of reactive, benign and malignant connective tissue lesions that may occur in the oral cavity.
To recognise the common causes of various types of localised gingival lesions
To understand the etiology and causes relevant to the development of these disorders.