As adjectives the difference between peroral and preoral
is that peroral is by way of the mouth while preoral is situated in front of, or anterior to, the mouth.
peroral
English
Adjective
(-)
(medicine) By way of the mouth.
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preoral
English
Alternative forms
* pre-oral
Adjective
(
en adjective)
(anatomy) Situated in front of, or anterior to, the mouth.