title: Muscle tension line concept in nasolabial muscle complex--based on 3-dimensional reconstruction of nasolabial muscle fibers.
abstract: BACKGROUND
  Plastic surgeons have attempted various ways to rebuild the aesthetic subunits of the upper lip in patients with cleft lip with less than perfect results in most cases. We propose that repairing the 3 muscle tension line groups in the nasolabial complex will have improved aesthetic results.
  
  
  METHODS
  Micro-computed tomographic scans were performed on the nasolabial tissues of 5 normal aborted fetuses and used to construct a 3-dimensional model to study the nasolabial muscle complex structure.
  
  
  RESULTS
  The micro-computed tomographic (CT) scans showed the close relationship and interaction between the muscle fibers of nasalis, pars peripheralis, levator labii superioris, and pars marginalis.
  
  
  CONCLUSIONS
  Based on the 2-dimensional images obtained from the micro-computed tomographic scans, we suggest the concept of nasolabial muscle complex and muscle tension line group theory: there is a close relationship among the alar part of the nasalis, depressor septi muscle, orbicularis oris muscle, and levator labii superioris alaeque nasi. The tension line groups are 3 tension line structures in the nasolabial muscle complex that interlock with each other at the intersections and maintain the specific shape and aesthetics of the lip and nose.
authors.affiliation: From the Center for Cleft Lip and Palate Treatment, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors.forename: Ningbei
authors.initials: N
authors.lastname: Yin
authors.forename: Jiajun
authors.initials: J
authors.lastname: Wu
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.forename: Tao
authors.initials: T
authors.lastname: Song
authors.forename: Hengyuan
authors.initials: H
authors.lastname: Ma
authors.forename: Zhenmin
authors.initials: Z
authors.lastname: Zhao
authors.forename: Yongqian
authors.initials: Y
authors.lastname: Wang
authors.forename: Haidong
authors.initials: H
authors.lastname: Li
authors.forename: Di
authors.initials: D
authors.lastname: Wu
mesh_terms: D002971:Cleft Lip / Q000601:surgery; D004954:Esthetics; D005152:Facial Muscles / Q000033:anatomy & histology*; D005333:Fetus; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008046:Lip / Q000033:anatomy & histology*; D018485:Muscle Fibers, Skeletal / Q000166:cytology*; D009129:Muscle Tonus / Q000502:physiology*; D055171:Nasal Cartilages / Q000033:anatomy & histology; D009666:Nose / Q000033:anatomy & histology*; D019651:Plastic Surgery Procedures / Q000379:methods; D055114:X-Ray Microtomography / Q000379:methods