In fact, the fricatives [f] and [v] often have lateral airflow, but no language makes a distinction for centrality, and the allophony is not noticeable.
The labiodental flap occurs phonemically in over a dozen languages, but it is restricted geographically to central and southeastern Africa.
It has been reported to occur phonemically in a dialect of Teke, but similar claims in the past have proven spurious.
[9] Dentolabial consonants are the articulatory opposite of labiodentals: They are pronounced by contacting lower teeth against the upper lip.
These are rare cross-linguistically, likely due to the prevalence of dental malocclusions (especially retrognathism) that make them difficult to produce,[10] though the voiceless dentolabial fricative [f͆] is used in some of the southwestern dialects of Greenlandic.