Which cyst is regarded as the SOFT TISSUE counterpart of the lateral periodontal cyst?

Correct answer: D. Gingival cyst of the adult

• A. The calcifying odontogenic cyst is defined by GHOST CELLS with dystrophic calcification and has both cystic and neoplastic forms — a completely different entity.
• B. The radicular cyst is INFLAMMATORY in origin, arising from the rests of Malassez stimulated by pulpal necrosis. It is the most common odontogenic cyst and is always associated with a NON-VITAL tooth.
• C. The gingival cyst of the NEWBORN (Bohn nodules, Epstein pearls) consists of multiple small keratin-filled inclusion cysts on the alveolar ridge or palate of an infant. They are extremely common and involute spontaneously within weeks; no treatment is needed.
• D. CORRECT. The GINGIVAL CYST OF THE ADULT and the lateral periodontal cyst share an identical origin (the rests of the dental lamina), identical histology (a thin non-keratinised lining with characteristic focal epithelial plaques and clear glycogen-rich cells), and an identical site of predilection — the MANDIBULAR CANINE AND PREMOLAR region of middle-aged adults. The only difference is location: the gingival cyst is confined to SOFT TISSUE on the facial gingiva, appearing as a small bluish-grey dome, while the lateral periodontal cyst is INTRAOSSEOUS. Both are treated by simple excision.

Note: Vitality testing separates the interradicular radiolucencies: the LATERAL PERIODONTAL cyst sits between the roots of VITAL teeth, while a lateral radicular cyst arising from a lateral canal is associated with a NON-VITAL tooth. Always test before you treat.