title: New details on the clefted uvular muscle: analyzing its role at histological scale by model-based deformation analyses.
abstract: OBJECTIVE
  As an initial step to a complex reconstruction model for virtual surgery, the present study was carried out to provide data on the prenatal cleft lip and palate uvular muscle in eight specimens.
  
  
  METHODS
  Serial sections of viscerocrania of 18 aborted embryos and fetuses were studied microscopically and segmented manually. Registration, three-dimensional reconstruction, and finite element analyses were conducted.
  
  
  RESULTS
  Incompletely clefted uvulae showed anterior fusion and dorsal fission of the bilateral uvular muscle bodies. A complete cleft lip and palate specimen evidenced single bilateral uvular muscle bodies lying medially and orally below the cleft shelf, its central longitudinal fibers running beneath the oral-median mucosa. In incompletely clefted uvulae, 10% to 50% of circular peripheral fibers crossed the midline within the central third of the anterioposterior muscle, behind the levator loop. Of the fibers, 30% to 60% crossed to the ipsilateral palatopharyngeus muscle. Fibers inserted into the uvular basal membrane in a 60% nasal and 40% oral distribution at the middle third of the macroscopically clefted uvula. The macroscopic uvula itself consisted of loose connective tissue and salivary glands. Deformation analysis did disclose local stress, suggesting the uvular muscle contributes to velopharyngeal closure in normal anatomy and extends the cleft edges in cleft palate.
  
  
  CONCLUSIONS
  Cleft lip and palate reconstruction should reasonably use the uvular muscle to augment the velar midline bulk. Uvular muscle deformation calculation was successful, permitting functional insight on the basis of microanatomical specimens, so far a bigger complete velar model can be ventured.
authors.affiliation: Maxillofacial and Facial Plastic Surgery, Johann Wolfgang Goethe–University Medical Center, Frankfurt am Main, Germany. constantinlandes@googlemail.com
authors.forename: Constantin A
authors.initials: CA
authors.lastname: Landes
authors.forename: Frank
authors.initials: F
authors.lastname: Weichert
authors.forename: Thomas
authors.initials: T
authors.lastname: Steinbauer
authors.forename: Andreas
authors.initials: A
authors.lastname: Schröder
authors.forename: Lars
authors.initials: L
authors.lastname: Walczak
authors.forename: Helga
authors.initials: H
authors.lastname: Fritsch
authors.forename: Mathias
authors.initials: M
authors.lastname: Wagner
mesh_terms: D016477:Artifacts; D002102:Cadaver; D005205:Fascia / Q000196:embryology; D005333:Fetus / Q000196:embryology*; D020342:Finite Element Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D010156:Palatal Muscles / Q000196:embryology*; D010609:Pharyngeal Muscles / Q000196:embryology*; D013194:Staining and Labeling; D014609:Uvula / Q000196:embryology*