Nicolas and Prenant have described a curious case of this anomaly in a sheep.

Gurlt has named subjects presenting the total or partial absence of the inferior maxilla, agnathes or hemiagnathes.
Simple atrophy of the inferior maxilla has been seen in man as well as in the lower animals, but is much less frequent than atrophy of the superior maxilla.

Langenbeck reports the case of a young man who had the inferior maxilla so atrophied that in infancy it was impossible for him to take milk from the breast.

He had also almost complete immobility of the jaws.

Boullard reports a deformity of the visage, resulting in a deficiency of the condyles of the lower jaw.