CORRECTION SECTION: Accidentally switched narrow and wide buccal corridors. Wide smile = narrow buccal corridors. Narrow smile = wide buccal corridors. Summary: Narrow maxilla, narrow nasal cavity, dental crowding, narrow buccal corridor, chronic nasal congestion, low resting tongue posture, mouth breathing, deviated septum, obstructive sleep apnea, tongue scalloping, high arched palate. Sources: Relationship between dental arch width and vertical facial morphology in untreated adults Buccal corridors and smile esthetics