We don't have synonyms for aphthae yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are aphtha.
(n) :
(pathology) Candidiasis, oral thrush, thrush (fungal infection of the mucous membranes of the mouth caused by any species of yeast from the genus Candida).
(n) :
(pathology) Candidiasis, oral thrush, thrush (fungal infection of the mucous membranes of the mouth caused by any species of yeast from the genus Candida).