['BTX-A is the standard treatment for glabellar furrows. However, some individuals have resting glabellar rhytides that are sufficiently deep that they respond poorly to BTX-A alone.', 'To compare the efficacy of BTX-A combined with intradermal Hylan B with the efficacy of BTX-A alone in individuals with moderate to severe glabellar rhytides.', 'This was a retrospective study of 16 subjects with moderate to severe glabellar rhytides. Their response to Hylan B plus BTX-A was compared clinically and photographically to their response to BTX-A alone.', 'All subjects had moderate or severe glabellar rhytides at rest before treatment. After BTX-A alone, none (0%) had achieved no or mild rhytides. After BTX-A and Hylan B injection, only 1 of 16 (6%) had moderate glabellar rhytides, with the remainder (94%) being mild.'] Do deep resting glabellar rhytides respond to BTX-A and Hylan B?