Résumé
Objective To evaluate the diffuse characteristics of two types of botulinum toxin type A (BOTOX and CBTX A) in the forehead and the effect of intradermal (ID) and subcutanous (SC) infections on their diffusion.Methods Healthy volunteers (n =20) were recruited to receive a 0.05 ml (2 U) injection of botulinum toxin type A at four forehead sites [both sides of medial forehead (SC) and temporal forehead (ID)],one side for BOTOX and another for CBTX-A.On day 14,the Minors' iodine starch test was performed and photographs were taken for calculating the area and dimensions of anhydrotic area.Results The areas of anhidrosis ID were significantly greater with CBTX-A (180±15) mm2 than that of BOTOX (144±14) mm2.The same conditions occurred in vertical dimensions (14.4±1.1) mm vs.(15.8±1.0) mm and horizontal dimensions (10.8±0.6) mm vs.(12.5±0.7) mm.There was significant variation between the both for diffuseness in the two anhidrotic halos observed after ID injection (P＜0.05).The areas of anhidrosis by SC were significantly greater with CBTX-A (207±17) mm2 than that in BOTOX (183±18) mm2.The mean horizontal dimension was greater with CBTX-A by SC (13.2±0.6) mm than that of BOTOX by SC (12.2±0.7) mm,but not statistically significant (P =0.06).The mean horizontal dimension in BOTOX was significantly greater with SC than that with ID (P＜0.05).There was no statistically significant difference between SC and ID administration of CBTX-A.Conclusions BOTOX diffuses less than CBTX-A.ID injection technique may result in less diffusion than SC.