Bidental consonants are consonantsarticulated with both the upper and lower teeth. They are normally found only indisordered speech, and are distinct frominterdental consonants such as[n̪͆], which involve the tongue articulated between the teeth rather than the teeth themselves. The diacritic for bidental consonants in theextensions to the IPA is the same superscript plus subscript bridge, ⟨◌̪͆⟩:
People withhypoglossia (abnormally small tongue) may use bidental fricatives to target/s/ and/z/.
There is at least one confirmed attestation of a bidental consonant in the inventory of a natural language. TheBlack Sea sub-dialect of theShapsug dialect ofAdyghe has avoiceless bidental fricative where other dialects have[x], as in хы[xə]ⓘ "six". It has been transcribed as ⟨x̪͆⟩, reflecting its value in other dialects, but there is no frication at thevelum and it would thus be better transcribed as ⟨h̪͆⟩. The teeth themselves are the only constriction: "The lips [are] fully open, the teeth clenched and the tongue flat, the air passing between the teeth; the sound is intermediate between[ʃ] and[f]".[2]
