Periodontics · single question
What does post-crossbite EXCEPT include? Tongue thrust is a cause, pacifier is a cause — which is NOT a cause of posterior crossbite?
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Correct answer: B. Microglossia (small tongue) — would PREVENT crossbite by not pushing teeth buccally
- A. Chronic mouth breathing (airway obstruction from adenoids/tonsils) leads to low tongue posture and maxillary constriction → posterior crossbite.
- B. Correct. MICROGLOSSIA (abnormally small tongue) is NOT a cause of posterior crossbite — in fact, a small tongue provides LESS outward pressure on the maxillary teeth, which might predispose to crossbite due to LACK of normal tongue pressure, but microglossia does not actively cause crossbite. Macroglossia (large tongue) can cause spacing and prognathism.
- C. Tongue thrust IS a cause of crossbite — abnormal anterior tongue pressure during swallowing can push teeth buccally.
- D. Prolonged pacifier use causes narrowing of the maxillary arch and posterior crossbite.