High Quality Content by WIKIPEDIA articles! In standard English, both in Britian and the United States, the phonetic realisation of the dental fricative phonemes shows less variation than for many other English consonants. Both are pronounced either interdentally, with the blade of the tongue resting against the lower part of the back of the upper teeth and the tip protruding slightly (though less prominently than for the corresponding sound in Spanish) or alternatively with the tip of the tongue against the back of the upper teeth. The interdental position might also be described as "apico-" or "lamino-dental". These two positions may be free variants, but for some speakers they are complementary allophones, the position behind the teeth being used when the dental fricative stands in proximity to an alveolar fricative, as in clothes (/ðz/) or myths (/?s/). Lip configuration may vary depending on phonetic context.