During fricative sounds ('F' sounds), where are the upper (maxillary) teeth positioned relative to the lower lip?

Correct answer: A. Inner third of the lower lip (wet-dry border/vermilion border area)

• A. Correct. During 'F'/'V' fricative sound production, the maxillary incisal edges should lightly contact the wet-dry (vermilion) border area, approximately the inner third of the lower lip — a key phonetic check for proper anterior tooth position in denture fabrication.
• B. Contact on the outer (dry) surface of the lip suggests the teeth are positioned too far forward/labially.
• C. No contact at all would suggest the teeth are positioned too far back/lingually or are too short.
• D. This does not correspond to the mechanism of 'F' sound production, which involves the upper teeth and LOWER lip.