Interdental consonant

Interdental consonants are produced by placing the tip of the tongue between the upper and lower front teeth. That differs from typical dental consonants, which are articulated with the tongue against the back of the upper incisors. No language is known to contrast interdental and dental consonants.

Interdental consonants may be transcribed with the extIPA subscript plus superscript bridge (⟨◌̪⟩ + ⟨◌͆⟩ = ⟨◌̪͆⟩), as in ⟨n̪͆ t̪͆ d̪͆ θ̪͆ ð̪͆ r̪͆ ɹ̪͆ l̪͆ ɬ̪͆ ɮ̪͆⟩, but it is also common to transcribe them as advanced dentals, as in ⟨n̪̟ t̪̟ d̪̟ θ̟ ð̟ r̪̟ ɹ̪̟ l̪̟ ɬ̪̟ ɮ̪̟⟩, or even as advanced alveolars, as in ⟨n̟ t̟ d̟ r̟ ɹ̟ l̟ ɬ̟ ɮ̟⟩.

Interdental consonants are rare cross-linguistically. Interdental realisations of otherwise-dental or alveolar consonants may occur as idiosyncrasies or as coarticulatory effects of a neighbouring interdental sound. The most commonly-occurring interdental consonants are the non-sibilant fricatives (sibilants may be dental but do not appear as interdentals). No language is known to contrast interdentals with dentals of the same manner.