subcrestal pocket

sub·crest·al pock·et

a pocket extending apically below the level of the adjacent alveolar crest. Synonym(s): infrabony pocket, intrabony pocket

in·fra·bon·y pock·et

, intrabonypocket (infră-bōnē pokĕt, intră-) Pocket extending apically below the level of the adjacent alveolar crest.
Synonym(s): subcrestal pocket.