Glabellar contraction patterns: a tool to optimize botulinum toxin treatment.
BACKGROUND
Botulinum toxin is a well-established treatment for dynamic glabellar lines. A previous study evaluated the existence of glabellar contraction "patterns," according to the predominance of eyebrow approximation, depression, or elevation movements, namely "U," "V," "convergent arrows," "omega," and "inverted omega."


OBJECTIVE
To confirm contraction patterns in the adult population for a better treatment approach and to verify whether changes occur after repeated treatment.


METHODS
Pairs of photographs-at rest and under contraction-from two groups were retrospectively analyzed: 334 adult volunteers with a predominance of specific movements, being verified and 36 previously treated individuals when they returned for re-injections.


RESULTS
The five glabellar contraction patterns were confirmed. Each individual's initial pattern reappeared upon waning of the toxin effect.


CONCLUSIONS
Interpersonal differences in facial animation are observed. Classifying glabellar wrinkles allows accurate treatment with botulinum toxin, injecting the most commonly recruited muscles with higher doses or into more sites. Muscles not so recruited are spared or injected with lower doses for more-effective and -natural results. Although botulinum toxin blockade causes recruitment of adjacent muscles, the initial muscle contraction pattern is resumed when the effect wanes.
Dermatology Clinic, Hospital do Servidor Público Municipal de São Paulo, São Paulo, Brazil. artrindal@uol.com.br
Ada R Trindade
AR
de Almeida
Elisa R M
ER
da Costa Marques
Raul
R
Banegas
Bogdana V
BV
Kadunc
D000328:Adult; D000368:Aged; D001905:Botulinum Toxins / Q000008:administration & dosage*; D005152:Facial Muscles / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects; D009465:Neuromuscular Agents / Q000008:administration & dosage*; D010781:Photography; D012189:Retrospective Studies; D015595:Skin Aging / Q000187:drug effects
D009465:Neuromuscular Agents; D001905:Botulinum Toxins