title: The influence of a gummy smile on lip seal.
abstract: OBJECTIVE
  The purpose of this study was to verify the influence of excessive gingival display on lip seal.
  
  
  METHODS
  Eighteen individuals with gummy smiles and poor lip seal were submitted to orofacial myofunctional assessment and surface electromyography in order to verify the action potential amplitude of mentalis muscle action generated during muscular exertion. Periodontal surgery was performed to remove excessive gingival tissue and bone volume from the pre-maxilla, and after 6 months, the patients were re-evaluated.
  
  
  RESULTS
  Decreased contraction and tensing of the mentalis muscle (chin dimpling) was clinically observed when attempting lip seal and electromyographical analysis revealed a statistically significant difference among action potential values during muscular exertion to achieve lip contact.
  
  
  CONCLUSIONS
  It was concluded that lip seal is influenced by gingival bone volume and that surgical removal contributed to a smoother contact between the lips.
authors.affiliation: Postgraduate Program in Health Sciences, Universidade Federal do Rio Grande do Norte - UFRN, Natal-RN, Brazil. gigasparino@uol.com.br
authors.forename: Giselle Gasparino
authors.initials: GG
authors.lastname: dos Santos
authors.forename: Delane Maria
authors.initials: DM
authors.lastname: Rego
mesh_terms: D000328:Adult; D004576:Electromyography; D005152:Facial Muscles / Q000502:physiology; D005260:Female; D005881:Gingiva / Q000033:anatomy & histology*; D006801:Humans; D008046:Lip / Q000502:physiology*; D008297:Male; D012904:Smiling; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires