Bidental consonants are consonants articulated with both the upper and lower teeth. They are normally found only in disordered speech, and are distinct from interdental consonants such as, which involve the tongue articulated between the teeth rather than the teeth themselves. The diacritic for bidental consonants in the extensions to the IPA is the same superscript plus subscript bridge, ⟨◌̪͆⟩:A bidental percussive,, produced by striking the teeth against each other. A voiceless bidental fricative,, a fricative made through clenched teeth with no involvement of the tongue or the lips, a "bidental (consonant) produced by air passing through the closed front teeth". A voiced bidental fricative,, a fricative made through clenched teeth with no involvement of the tongue or the lips, and vibration of the vocal cords. Bidental aspiration of another consonant, such as or.