title: Application of Local Injection of Botulinum Toxin A in Cosmetic Patients with Congenital Drooping Mouth Corner.
abstract: OBJECTIVE
  This study aimed to investigate the clinical application and efficacy of local injection of botulinum toxin A (BTX-A) at the depressor anguli oris in patients with congenital drooping mouth corner.
  
  
  METHODS
  From September 2013 to March 2015, 36 cosmetic patients received local injections of botulinum toxin A at the depressor anguli oris, with 1-3 injection sites in the moving region of the depressor anguli oris on each side. At each injection site, 2-4 U of BTX-A was injected, and the total dose for any unilateral treatment did not exceed 8 U. The change in the degree of drooping of the mouth corner before and after the injection was analyzed using statistical methods. The clinical efficacy, preservation time, and adverse reactions were observed.
  
  
  RESULTS
  The degree of drooping of the mouth corners of the cosmetic patients before the treatment was compared with that at 1 month after using a paired t test, and the difference was statistically significant, with P < 0.01. The treatment results were satisfactory, and the effect was preserved for 6-9 months. None of the 36 cosmetic patients had any complications of bruising, infection, dysfunction in opening and closing the mouth, smile asymmetry, drooling, or dysarthria after the injection.
  
  
  CONCLUSIONS
  The local injection of BTX-A at the depressor anguli oris can effectively lift a drooping mouth corner, thereby improving the depressed, stern, and aged appearance of the face. The performance of this treatment is simple, safe, and easy to perform in clinical applications.
  
  
  METHODS
  This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
authors.affiliation: Department of Plastic and Reconstructive Surgery, Beijing Chao-Yang Hospital, Capital Medical University, #8 Gongren Tiyuchang Nanlu, Chaoyang District, Beijing, 100020, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Qian
authors.affiliation: Department of Plastic and Reconstructive Surgery, Beijing Chao-Yang Hospital, Capital Medical University, #8 Gongren Tiyuchang Nanlu, Chaoyang District, Beijing, 100020, People's Republic of China.
authors.forename: Yan-Kun
authors.initials: YK
authors.lastname: Zhang
authors.affiliation: Department of Plastic and Reconstructive Surgery, Beijing Chao-Yang Hospital, Capital Medical University, #8 Gongren Tiyuchang Nanlu, Chaoyang District, Beijing, 100020, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Lv
authors.affiliation: Department of Plastic and Reconstructive Surgery, Beijing Chao-Yang Hospital, Capital Medical University, #8 Gongren Tiyuchang Nanlu, Chaoyang District, Beijing, 100020, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Hou
authors.affiliation: Department of Plastic and Reconstructive Surgery, Beijing Chao-Yang Hospital, Capital Medical University, #8 Gongren Tiyuchang Nanlu, Chaoyang District, Beijing, 100020, People's Republic of China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Cao
authors.affiliation: Department of Plastic and Reconstructive Surgery, Beijing Chao-Yang Hospital, Capital Medical University, #8 Gongren Tiyuchang Nanlu, Chaoyang District, Beijing, 100020, People's Republic of China. drjufengfan@163.com.
authors.forename: Ju-Feng
authors.initials: JF
authors.lastname: Fan
mesh_terms: D000328:Adult; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D015331:Cohort Studies; D004954:Esthetics; D005146:Facial Asymmetry / Q000151:congenital* / Q000188:drug therapy*; D005149:Facial Expression; D005152:Facial Muscles / Q000187:drug effects* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008046:Lip / Q000187:drug effects; D008297:Male; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D019274:Botulinum Toxins, Type A
keywords: Botulinum toxin A; Congenital drooping mouth corner; Depressor anguli oris