Oral Pathology and Oral Medicine
Core concepts
Organize lesions by category: developmental (odontoma, amelogenesis imperfecta, dens invaginatus), inflammatory/reactive (periapical granuloma, radicular cyst, pyogenic granuloma, peripheral giant cell granuloma), cystic (dentigerous, odontogenic keratocyst, nasopalatine duct cyst), and neoplastic (ameloblastoma, squamous cell carcinoma, salivary gland tumors). Learn the classic clinical and radiographic features that distinguish them, plus oral manifestations of systemic disease (diabetes, leukemia, HIV, nutritional deficiencies) and potentially malignant disorders (leukoplakia, erythroplakia, oral submucous fibrosis).
Traps
Stems often present a lesion with overlapping features; the discriminator is usually location, age, or radiographic appearance. Dentigerous cyst attaches at the CEJ; OKC often grows anteroposteriorly with minimal expansion and has a high recurrence rate. Radicular cyst is always associated with a nonvital tooth. Beware confusing pyogenic granuloma (vascular, bleeds easily) with peripheral giant cell granuloma (multinucleated giant cells). For malignancy, remember red flags: induration, fixedness, non-healing ulcer >2 weeks, lymphadenopathy.
Worked example
Rule of thumb: "A well-defined unilocular radiolucency around the crown of an impacted third molar, attached at the CEJ = dentigerous cyst." If the stem adds a nonvital tooth, switch to radicular cyst. If it adds a soap-bubble multilocular appearance in the posterior mandible of a young adult, think ameloblastoma.