## Most Common Site of Oral Lichen Planus **Key Point:** The buccal mucosa (inner cheeks) and attached gingiva are the most frequently affected sites in oral lichen planus, accounting for approximately 70–80% of oral cases. ### Clinical Presentation at Common Sites | Site | Frequency | Presentation | Clinical Significance | |------|-----------|--------------|----------------------| | **Buccal mucosa & gingiva** | 70–80% (Most common) | Reticular white patches, erosions, erythema | Often symptomatic; may interfere with eating | | Hard palate | 20–30% | White striae, less erosive | Usually asymptomatic | | Dorsum of tongue | 10–15% | Atrophic patches, loss of papillae | Rare; often incidental | | Floor of mouth | <5% | Erosions, ulceration | Uncommon; high malignant potential if involved | **High-Yield:** Buccal mucosa and gingiva involvement is so characteristic that it is considered the **classic presentation** of oral lichen planus in most textbooks and examination questions. ### Why This Site? 1. **Mechanical trauma zone:** Buccal mucosa and gingiva are subject to constant friction from teeth, food, and mastication. 2. **Mucosal permeability:** These areas have relatively thin epithelium and higher permeability to antigens. 3. **Immune accessibility:** Proximity to underlying lymphoid tissue and dendritic cell populations. **Clinical Pearl:** Erosive oral lichen planus (especially on buccal mucosa and gingiva) carries a 0.5–5% risk of malignant transformation to oral squamous cell carcinoma over 10 years; regular monitoring is essential. **Mnemonic:** **BIG** = **B**uccal mucosa, **I**nner cheeks, **G**ingiva — the most common sites.
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.